2D flow visualization by laser holograph interferometery in shock tube and some applications in Computational Flow Imaging are presented.

Multiphase pipeline flow is very important to oil, gas and process industry. This is a class of problems where comprehensive simulations, although desirable on physical grounds, are not practical due to the large aspect ratio between the pipe length and diameter. In order to enhance the understanding of the pipeline flow, as well as to validate and identify the critical aspects of these models, intensive experimental data are needed. This will define how these models can be improved.

Improvements on the Global Rainbow Thermometry (GRT) technique are being presented. The GRT technique allows us to study the physical properties of liquid-in-liquid and liquid-in-air dispersions. In this paper the influence of droplet non-sphericity on the size and temperature measurements of liquid droplets suspended in a liquid or a gaseous bulk will be analyzed. A new theoretical model that takes into account the effect of the non-spherical droplets on the GRT signal will be proposed and a data inversion algorithm is described. It allows to automatically find the optimized parameters of the simulation of experimental Global Rainbow patterns. Expeirmental validation of the rainbow thermometry technique is performed, measuring the droplet size and temperature by means of alternative techniques to compare with the present method. For this purpose, an original experiment has been designed.

Digital speckle correlation method (DSCM) is based on the correlation-matching search algorithm, in which the correlation coefficient is used as a criterion for matching of two speckle patterns. The properties of the correlation coefficient affect the accuracy and the searching speed of DSCM. As many as ten different definitions of the correlation coefficient can be found in literatures but almost no comparison works are reported. In this paper, the different coefficient equations are compared and the properties of all these definitions are concluded. The comparison results may help to improve the development and application of DSCM in future. Some new correlation coefficients with better properties are then defined on the basis of the comparison.

Cell growth experiments are used to determine the effects that various environmental factors have on the development and life cycles of cells. For current earth-based testing, the experiments are conducted in Erlenmeyer flasks on orbital shaker tables. This method has been used for several decades and serves as teh baseline-testing configuration. In the future, cell growth experiments will be conducted on the International Space Station (ISS), which will permit long duration testing of the effects of gravity on the development and life cycle of cells. Particle Image Velocimetry (PIV) has been used to measure the 3D velocity field within the flasks. The high-resolution PIV data have been used to calcluate accelerations and shear stresses that the cells typically encounter during testing. The PIV data will be used to verify that the fluid environment during testing on the ISS is comparable to that encountered during earth-based testing.

This paper describes a device for 3D profile measurement systems, which are based on grating projection method using phase shifting technique for fringe analysis. As a key component of these systems, we propose to apply a liquid crystal (LC) grating instead of a conventional ruled grating, which has difficulty in speedy and accurate shifting of the projected pattern. This LC grating consists of 960 lines of stripe pattern on the substrate of 60×40 mm² in size and has such features as 8 bits of gray levels in dynamic range in use of mono-chromatic applications. A sinusoidal pattern as well as a binary pattern in realized by combining pulse width modulation control and frame ratio control technqiue. In addition, the period of the pattern is arbitrarily controlled and shifting of the projected pattern is also electrically realized. We demonstrate a few examples measured by the system which uses this LC grating inside.

A digital in-line holography recording system was used in the holography particle image velocimetry for a 3D flow measurement that are made up of the new full field fluid mechanics experimental technique--DHPIV. In this experiment, the traditional holography film was replaced by a CCD chip that record the interference stripe directly without the darkroom processing, and the virtual image slices in different position were reconstructed by compuation using Fresnel-Kirchhoff integral from the digital image. Also, complex field signal filter was applied in image reconstruction to achieve the thin depth of image field that has strong effecting with the vertical velocity component resolution. Using the frame-straddle CCD techniques, the 3D velocity was computed by 3D cross-correlation through space interrogation block matching through the reconstructed image slices with digital complex field signal filter. Then the 3D velocity, vortex, iso-surface details and the time evolution movie in a 3D flow field were displayed by numerical computation and experimental measurement using this DHPIV method.

Convective motion in fluid dynamics and heat transfer is the most important phenomenon to be understood since it can greatly influence the performances of fluid and heat transfer systems in various manners. With the advances of modern technologies, new diagnostics for mapping 3D convective flow is veyr necessary for fundamentals of flow physics. Especially, modern computational modeling has been greatly advanced to demand 3D convective-flow diagnostics in order to verify and tune the methodologies and approaches. Conventional velocimetry is either pointwise or 2D. If available, 3D gross-field velocimetry can allow us unprecedented physical insight as well as the needed data for validation of numerical codes and understanding of funamental flow physics. In an effort to meet the need of 3D flow diagnostics, we have developed stereoscopic tracking velocimetry (STV). STV is based on the simultaneous stereoscopic monitoring of numerous particles dispersed in a carrier fluid. It can thus provide time-sequence velocity maps of an entire flow field. Here we briefly present the methodology of STV and its experimental measurement results of 3D flow fields including the traditional flow involving a free jet and the directional solidification for material processing.

In this paper, several techniques for fluid measurement, such as Optical Interferometry and Particle Image Velocimetry (PIV) etc. are introduced. And their applications on the fluid physics experiment of simulation microgravity on the ground in the national microgravity laboratory are presented. To reduce the gravitational effect on the ground, the character sizes reserached objects are generally very little. The measuring techniques of fluid mechanics have to be combined with micrology to carry out the measurement of little size.

The experiments are run in an inhomogeneous turbulent shearless layer generated in a wind tunnel with two different meshes. A PIV system synchronized simultaneously with a Mie scattering diffusion concentration system is used in order to obtain the velocity and concentration fields at the same instant. We present here some statistical results for both velocity and concentration and also the mean flux. Filtering and subgrid scale modeling are applied to experimental velocity and concentration field in order to check the effect of the length of filter and the accuracy of subgrid model of LES.

Parallel lines viewed in a picture taken with a camera appear to meet at a vanishing point. Three groups of parallel lines which are perpendicular each to other appear three vanishing-points in a perspective picture. This paper proposed an algorithm by which real 3D position of the viewpoint and imaging plane of the picture and the scale of the picture are determined based on positions of the three vanishing-points. In this paper the principle of perspective geometry, visual geometry, was also discussed, especially the vanishing-point theorem. Meanwhile, this paper also proposed a method by which real 3D positions of the objects are determined with a two-viewpoint imaging system.

A micro PIV system has been developed as a new diagnostic tool for micro scale flow and applied to the measurement of microchannel flow. The micro PIV system employs the incident-light fluorescent microscope system and utilizes high-power pulsed Nd:YAG lasers, a high-resolution CCD camera and 1 μm diameter fluorescent tracer particles. The velocity distributions of pressure-driven flow and pressure- and electrokinetically-driven flow in a microchannel were measured using the micro PIV system and the visualization of flow fields in a microchannel was demonstrated.

The paper studies three-component PIV techniques used in 3D flow field measurement. Lateral stereovision was employed to locate the spatial position of particles and a progressive approach was used to measure the position accurately. A new epipolar constraint algorithm for the corresponding match was put forward. The algorithm can reduce the search area under perspective distortion. Fuzzy pattern recognition was introduced to PIV adjacent frame matching and fuzzy clustering was employed to implement the moving analysis of local particles in double exposure PIV images. Finally, a simulated experiment of 3D PIV analysis was completed by the techniques mentioned above.

There are two basic configurations of stereoscopic particle image velocimetry (SPIV) systems: translation system and angular-displacement system. Theoretical and experimental error anaysis of SPIV is summarized. The results of theoretical error analysis indicate that the angular-displacement SPIV system with the Scheimpflug condition can provide up to 40% higher out-of-plane accuracy than the translation systems. Experimental error analysis of SPIV is to directly estimate the uncertainties from actual SPIV recordings after accurate automatic registration provided the imaged object's characteristics are known. Moreover, a liquid prism ensures that two camera continue to enjoy an orthogonal orientation with respect to the liquid-air interface.

In this paper an experiment on measurements of the wake of Goldfish carassius auratus swimming unrestricted was conducted in a water tunnel. Color liquid was used to visualize the wake of the fish and PIV was used to measure velocity field of the wake. Results show that there is reverse Karman vortex street in symmetrical plane of the fish's wake and the Strouhal frequency of the fish is about 0.35 udner the different experimental conditions. The distribution of velocity and vorticity in the wake of Goldfish was measured by PIV and formation of reverse Karman vortex street in the wake was studied in a model experiment.

SPIV was applied to a large-scale low-speed compressor facility with the configuration of the two CCD cameras placed on each side of the light sheet, so the periscope-type probe containing light sheet forming optics is not needed in the measurement, and the instantaneous velocity and vorticity distributions in several cross sections were successfully measured in the tip region of the compressor rotor at the design and near stall conditions. The results show SPIV would be a very attractive and powerful diagnostic tool for the study of complex turbomachinery flow. Some problems encountered in the measurement are also discussed.

An experimental investigation of Benard-Marangoni convection has been performed in double immiscible liquid layers of rectangular configuration. The two kinds of liquid are 10cst silicon oil and FC-70 respectively. The velocity fields in the vertical cross-section are obtained by PIV. Flow patterns and/or temperature distributions on the horizontal interface are displaced by using thermal color liquid crystal (TLC), and the velocity distributions on the interface were also obtained with the help of the serial particle image of TCL. The evolution processes of convection are observed in the differential thickness ratio of two liquid layers, and the convection styles are discussed.

The velocity fields of oscillatory convection have been measured using the techniques of Particle Image Velocimetry (PIV) in a liquid bridge of half floating zone with small typical scales of a few millimeters for emphasizing the thermocapillary effect in comparison with the effect of buoyancy. The flow patterns of the oscillatory flow have been studied experimentally in a liquid bridge. The flow patterns in the liquid bridge are classifeid with mode numbers according to oscillatory flow characteristics. Results of the experiment show that the mode depends on the aspect ratio as well as the volume ratio of the liquid bridge. The experimental results are helpful for studying the structure of flow at the onset of oscillatory thermocapillary convection in a liquid bridge.

The flow fields behind elliptic cylinders with different aspect ratios adjacent to a free surface were investigated experimentally in a circulating water channel. The elliptic cylinders tested in this study have same cross section area. For each elliptic cylinder, the experiments were carried out under different conditions by varying the submergence depth of the cylinder beneath the free surface. The flow fields were measured using a single-frame double-exposure PIV system. For each experimental condition, 350 instantaneous velocity fields were captured and ensemble-averaged to obtain the mean flow field information and spatial distribution of turbulent statistics. The near-wakes can be basically classified into three typical patterns, which are formation of Coanda effect, generation of substantial jet-like flow, and attachment of jet flow to the free surface. The general flow structures behind the elliptic cylinder are similar to previous results for a circular submerged near to a free surface. However, the wake width and the angle of downward deflection of the shear layer developed from the lower surface of the elliptic cylinder are smaller than those for the circular cylinder. These trends are enhance with increasing of the cylinder aspect ratios.

Electrospray is a process that relies on the electrostatic force to break the liquid into fine charged droplets. Electrospray ha several features by contrast with other atomization techniques. Since the size distribution of the droplets in electrospray is monodispersity when the spray operates under the Taylor-cone mode, and it is well controllable, the electrospray is applied in many fields such as material process, mass spectrometry technique, drag delivery, and ink jet print etc. In this paper, Dantex Flowmap 1500 PIV system with double-pulse Nd:YAG laser was used to measure the whole instantaneous velocity field of the electrospray droplets. The measuring results show that many effects, such as the applied voltage, flow rate, and temperature, will influence on the velocity distribution of the drops. The velocity distribution of the electrospray dorps is axisymmetric. The highly applied voltage will lead the droplets to accelerate during falling.

The detailed near-wake flow behind the Edge Blowing Mixture Curtain flameholder and the V-gutter flameholder were investigated by using 2D cross-correlation on-line PIV in a low speed wind tunnel. Experiments were conducted at the main flow velocity of 10m/s and 20m/s, the jet velocity of 10m/s and 20m/s respectively. Results show that near-wake flow structure of both flameholders is governed mainly by large-scale vortices in the form of vortex street, and the jet increase the size of the vortices. But symmetrical large-scale vortices appear when the momentum ratio of the jet to the main flow is high, which is disadvantage to combustion. Based on the research on the instantaneous flow, the instantaneous viewpoint of the flame stability mechanism was brought forwad. Important effect of alternate formation and shedding of vortices on the flame stability was discussed. All of these offer important theoretic basis for further studying combustion performance of the novel flameholder.

This paper presents an experimental study of the influence of 2D leading-edge geometry on transition and performance. The measurements were conducted on a special large-scale experimental facility, the pressure distribution and flow field were measured. The test model used in this study consists of circular leading edge and elliptic leading edge. Results are presented for a range of incidence. The measurement result indicated that the leading edge shape has a large influence on flow details, separation and transition as well as the boundary layer properties after reattached point.

A towing PIV system in large towing tank at China Ship Scientific Research Center is presented, also its application in the investigation on the effect on flow structure of juncture forms of stern appendage with submarine-like main-body. The coefficients of non-uniformity of the nominal wake for five juncture forms are assessed and compared.

This paper describes a study of the conditions inside a turbo-drill turbine cascade of high circulating flow coefficients using the PIV method. Measurements of velocity vector fields and derived vorticity were obtained and their characteristics determined. The fluid drill mechanical energy transfer, overall energy-losses and flow features responsible for these effects were investigated.

An agitator rig is built to observe the unsteady characteristics of the large vortex produced by the rotor-stator interaction in impeller machinery. Using a PIV, a speeder and an encoder, the instantaneous velocity measurement is finished at a group of rotating speeds and phase angles, respectively. The ensemble averaged velocity, vortex streamline and turbulent intensity are obtained from PIV data. The results show that the distribution of the instantaneous parameters has no periodicity. The ensemble-averaged vortex is mainly located in the neighborhood of the static vanes, and the phase angle has little influence on it. The turbulent intensity has similar characters with the vortex.

We present here a pretty simple method for matching the indices of refraction between a solid and a liquid, which is needed for flow visualization inside porous media. With this technique, a matched medium, consisting of Duran glass beads and a mixture of Dow Corning 550 and Dow Corning 556 is made. Experiments are conducted in an open channel with a porous bed and overlying fluid to investigate fluid dynamics in the interface region of fluid and porous. Using Particle Image Velocimetry, flow fields both in the fluid region and within porous region are obtained.

The laser diagnostic and visualization technology provides proper methods to understand the turbulence flow and the interaction between flow field and electricity field. In this paper, PIV is used to make instantaneous velocity measurements over a 120mm by 150mm area in the spray and detailed properties of electrospray are obtained. Small size particles are dispersed in spray space in advance and the vortices on the edge of spray are apparent in the measurement results. The comparison of velocity, turbulence momentum and vorticity between charge spray and conventional spray is presented.

Fuzzified neural network based on fuzzy number operations may be one of powerful fuzzified neural networks. We introduced a fuzzified neural network basd on fuzzy number operations which approximates targets by choosing the shapes of the weights and the biases and calculating the left, mean and right values of each weight or bias. However, as we have pointed out, the learning algorithm is a little time-consuming. We propose a parallel learning algorithm for the fuzzified neural network in this paper. The parallel learning algorithm works well for the fuzzified neural network.

The fluid flow associated with micro and meso scale devices is currently of interest. Experiments were performed to study the fluid flow in meso-scale channels. A straight flow tube was fabricated with 1.0×4.0mm² in rectangular cross section and 200mm in length, which was made of quartz for flow visualization and PIV measurements. Reynolds numbers were ranged from 311 to over 3105. The corresponding pressure drop was from 0.65KPa to over 16.58KPa between the inlet and outlet of the tube. The micro PIV was developed to measure the velocity distribution in the tube. A set of microscope object lens was mounted ahead of CCD camera to obtain optimzed optical magnification on the CCD chip. The velocity distributions near the outlet of the tube were measured to obtain full-developed flow. A CW laser beam was focused directly on the test section by a cylinder lens to form a small light sheet. Thus, high power density of light was formed on the view region. It is very important to the experiment while the velocity of the flow reaches to a few meters per second within millimeter scale. In this case, it is necessary to reduce exposure time to microseconds for PIV measurements. In the present paper, the experimental results are compared with the classical theories.

The phenomena of Portevin-Le CHaltelier (PLC) band propagation and its pulsation were investigated by using dynamic digital speckle pattern interferometry (DSPI). Pulsation of fringe density in the inside of the slip band accompanying with the serrations of load curve was observed. When the load falls in the serrations, the slip deformation happens just like an avalanche, and the specimen takes a shrinkage deformation in the outside of the slip band to compensate the elongation deformation in slip band, even for a tensile test. The maximum elongation in the slip band causing by the avalanchine slip is about 7.6 μm.

The measurement of in-plane surface strain is very important in structural material research. The traditional strain measurement techniques, however, have their clear constaint and inconveniency in terms of both sensor system arrangement and data analysis. This paper presents the development of a novel technique for estimating the local surface strain over a region. The key element of the technique is a high accurate image displacement detection algorithm. This algorithm is based on the Optical Flow concept and implemented in a multi-scale analysis scheme. This technique is aiming at covering large viewing area and detecting small deformation components on the top of large translation with high accuracy. A numerical differentiation procedure is also discussed to derive strain field from the displacement field. The test procedure of this technique is also presented in this paper. The test procedure consists of absolute translation calibration and strain calibration against strain-gauge measurement. The experimental results show a very good agreement between the proposed technique and the well-established traditional measurement.

Binary speckle correlation evaluated by computer simulations. Accuracy, sensitivity, computing speed and the image compression ratio are considered.

The signal to noise ratio of speckle pattern is unity, so it is difficult ot extract signal from a single speckle pattern. We have presentd a method of smoothing speckle fringe patterns is proposed, basing on the upper method. For a series of speckle fringe patterns, the location of the fringe is changing continually. According to the feature, the smoothing is implemented with great efficiency and speed.

A new method combining temporal phase analysis with dynamic digital speckle pattern interferometry is proposed to study Portevin-Le Chatelier effect quantitatively. The principle bases on that the phase difference of interference speckle patterns is a time-dependent function related to the object deformation. The interference speckle patterns of specimen are recorded with high sampling rate while PLC effect occurs, and the 2D displacement map of PLC band and its width are obtained by analyzing the displacement of specimen with proposed method.

A new full-field optical technique is developed to study surface deformation of solids. This method combines the measurement by grid method and the digital image processing. An optical information processing system and a digital image processing system of computer are used in this method. At the output plane we receive the pattern of grating lines taht can be used for the analysis of deformation of the specimen on which we have produced the phase grating. At last we show the application of this technique in the investigation of elastic-plastic fracture.

A technique for measuring in-place displacement under impact loading using digital speckle pattern interferometry (DSPI) with combining the digital subtraction and add mode is presented. A new technique of the add mode filtering is used. To grab the digital speckle of field produced by a pulse laser, an instantaneous digital image grabbing system is proposed. Thus the dynamic digital speckle image can be recorded and stored in a digital frame store. As an example, the displacement field of a semi-infinite model udner impact loading is measured.

In this paper, the digital speckle correlation method (DSCM) is selected as the experimental means to calculate the J integral of foil material. The deformation fields in the crack tip region are measured and their contour maps are shown. The formula using deformed field to calculate J integral is derived. Through calculating J integral of foil material by the DSCM, it is shown that this experimental method is a useful test technique in studying the mechanical behavior of film or foil materials.

In this paper, the technique of electronic sheraing speckle pattern interferometry with wide Audio-frequency driving vibration is used in non-destructive test of the multiply plywood structure. Test results show that we are able to evaluate promply the soundness of bonding of the plywood. In the process of test not only can we find any locations of defects from the synthesized intensity map very quickly, but also can obtain the shape, size and resonant frequency of every interior defect of the multiply plywood accurately.

The key problem to enhance the precision of displacements measurement with image correlation is to make the most of correlation behavior of speckle images. In fact, the artificial random speckles or natural texture, especially the microcosmic texture, on the object's surface have fractal characteristics, and the digital images of these patterns are also fractals. It is found that there is correlation between the fractal characteristics in un-deformed and deformed states of the images. Based on this fact a method called fractal correlation method, can be used to measure displacements. In this paper, the fractal correlation method was used to measure the displacement field on a crack tip of a metal specimen. The microcosmic natural texture on specimen's surface was taken as images, and the area was 1.397×1.397mm. By correlation operation with the fractal correlation method, curves of displacement around the tip can be obtained. The position of crack tip can be clearly distinguished from the displacement curves. The relationship of COD and distance behind the tip is linear. This agrees with the theory of fracture mechanics. The results also show that the plastic field does not distribute in uniform.

In this paper, an experiment is executed to analyze the displacement distribution of 56-ply composite laminates under three-point bending. In the experiment, the displacement fields on the two free edges of the laminated composite are measured by using the moire interferometry method and natural micro-image processing technique based on wavelet transform at the same time. In the first part of this study, a two-beam traditional moire interferometry experiment has been carried out. And in the second part, we present a new image processing method, which combines the theory of correlation and wavelet transform technique.

In this paper a Laser Moire deflectometry applicable for mini/micro-scale flow visualization is proposed. Based on the moire effect, the displacements of moire fringes can be used to calculate the deflection angle of laser beam, which is induced by the variation of refractive index in thermal flow fluid. Thus, density and temperature distribution of flow fluid can be obtained. The physical and mathematical model of the laser moire deflectometry is presented in detail. A digital image processing method of moire fringes by using Fourier transform is discused. The researches show that laser moire deflectometry can meet needs of mini/micro-scale temperature field for natural convection of a heated thin wire is experimentally demonstrated by means of the laser miore deflectometry.

The structure of the vortical flow behind a symmetrical airfoil of finite aspect ratio undergoing combinations of heave and pitch motions is investigated using qualitative dye flow visualization. The results are contrasted with flow visualizations obtained using electrolytic precipitation. The effect of changing the pitch amplitude is observed from the plan from view and wingtip view of the airfoil. With a Strouhal number of 0.35, Reyholds number based on airfoil chord of 164 and a phase angle of 90o, the maximum pitch amplitude is varied from 0° to 20°. The geometry of the downstream vortical flow is observed to change suggesting that the induced velocity from interacting structures decreases at lower pitch amplitudes. The rate of dynamic stall development may also be affected by variations in pitch amplitude since it appears that the timing of leading edge separation is affected. The flow field of an airfoil flapping periodically about a fixed axis appears to be influenced by the amplitude of pitching oscillations. At the tested Strouhal numbers the vortex formations appear to be primarily dependent on airfoil oscillation rather than heave translation. Furthermore, the results suggest that the wake structures originating from the dynamic stall process are important for the analysis of these complex flows. While the results from the two flow visualization techniques are similar, the dye flow visualization images provide greater qualitative insight. Inherently, precipitative techniques such as the one used here could provide good flow visualizations since the smoke/particles leave the surface of the airfoil, but the setup is found to be very sensitive to potential changes. The ion content in the electrolytic material was also found to play a role. Furthermore, the high ablation rate of the technique presented some practical problems.

The light sheet technique provides a unique method of visualization for off-body flow fields at subsonic through supersonic speeds. But conventional mirror tansmission laser systems have some shortcomings: The harsh environments of high speed wind tunnels often cause the misalignment of the optical components and the contamination of the mirror surfaces. The exposed laser beam is dangerous to the persons at the work sites. This paper presents an advanced optical-fiber-transmission laser sheet system, which provides a solution to the problems above and greatly improves the quality, safety and reliability of the light sheet. The emphasis is laid on the detailed composition of the new type visualization system. Some examples of its applications in transonic/supersonic wind tunnels are also given in this paper.

Full surface strain measurement requires the determination of two out-of-plane and four in-plane displacement gradient components of the surface strain tensor. Shearography is a full-field speckle interferometry technique with a sensitivity predominately to the out-of-plane displacenet gradient. Speckle pattern photography has the sensitivity to the in-plane displacement, and taking the derivative yields the in-plane dipslacment gradient. In this paper the two techniques are combined to yield a single-access multi-component surface strain measurement using shearography to measure the out-of-plane components and speckle pattern photography to measure the in-plane components. Results are presented of a multi-component surface strain measurement.

In this paper, an explosion, which starts at the center of a vortex, is considered. A shock tube was used to conduct the experiment. A vortex is generated when the shock wave propagates around a wing-shaped model. The explosion is triggered at the time when the vortex arrives at the position where the explosion wire is located. Holographic interferometery was used to visualize the vortex-explosion interaction. Both experimental and numerical results showed that a vortex, after disturbed by an explosion, is strongly deformed and smeared out, which suggets that vortex might be suppressed or even destroyed with an explosion. More careful works need to be carried out in the near future in order to get more detailed and quantitative information for both academic and application interests.

Wax-crystal morph is one of the prime inner factors that influence the rheological property of waxy crude at low temperature. The normal way to identify wax-crystals is comparing qualitatively the wax-crystals obtained from video-microscopy. The paper studies a quantitative characterization and classification of wax crystals of waxy crude oils. In this paper, a blocked 2D etropy threshold method was used to segment wax crystal images, and the grain size, shape characters of wax crystals and the continuous liquid phase characters are extracted through a statistic method. Finally, the fuzzy clustering method was employed to classify the wax crystal images.

In order to find a new method to compare the theory results with experiment results, it is necessary to develop the technique of computer simulating flow visual, which gets flow visual image from the computational flow field data. The computer simulation technique for flow visualization is the technique of CFI. CFI is succinctly defined as the art and science of generating digital images of theoretical fluid observations of real flow fields. It involves numerical value calculation, image processing, computer graph and other techniques. In this paper, we study four kinds of CFI technique. They are CFI-Schlieren, CFI-Shadowgraph, CFI-Interferometry and CFI-Color Schlieren. The algorithms of CFI-Color Schlieren and CFI-Interferometry are amply dissertated and some computational images are provided. Then we have accomplished the laser holographic interferometry experiments of shock wave diffracting double cubes model. We compare experimental interferograms with CFI images. The result verifies the validity of the theory. The comparisons of the computation with experiment are given in this paper. At the same time, we have developed the computer simulation software for flow visualization. The software provides a new approach to test and verify experiment and theory result. This paper also gives a description about the design method and function of the software. In the end, we also discuss the developing direction of the future.

Computational flow imaging (CFI) uses theoretical predictions of the interaction and transmission of optical waves through theoretical flowfield to generate digital pictures that simulate real observations, but the phase data produced by interferometric, Schlieren or shadow graph is the result of the integration of the refractive index or refractive index or refractive index gradient along the line-of-sight. The goal of this research is to develop a fast, efficeint ray casting method for integral calculation of computational flow imaging. We use a preprocessing procedure that the whole flow region is divided into new regular blocks in which the voxels are distributed by x and y coordinates to increase the processing speed. The algorithms are generally enough to handle non-convex, curvilinear or irregular grids and cells and grids constructed from multiple grids of CFD solutions.

A new moire interferometer, known as multifunction 3D function interferometry system is developed by authors, which combines the advantages of four-beam moire interferometer with the Twyman/Green interference system. The system can measure in-plane and out-of-plane deformation synchronously with high accuracy and high sensitivity. A compact phase shifter is used to improve the measurement sensitivity. The optical theory, components, key techniques, unique ability, and specifications of the system are described in detail in this paper. Some typical experiments using this system have been done and gained good results.

A combined system of four beams moire interferometer and incremental hole-driling machine was designed and applied for residual stress measurement. Two typical experiments were done using this system: non-uniform in-depth residual stress measurement of an ultrasonic shot-peening Aluminum plate; non-uniform in-plane residual stress measurement of an elastic-plastic Aluminum bent beam. Experiments results show good accordant with other measurement results and theory analysis results.

A new focused ion beam (FIB) miore method is proposed to measure the in-plane deformation of object in a micrometer scale. The FIB moire is generated by the interference bewteen a prepared specimen grating and FIB raster scan lines. The principle of the FIB moire is described. Several specimen gratings with 0.14 and 0.20 micron spacing are used to generate FIB miore patterns. The FIB moire method is successfully used to measure the residual deformation in a MEMS structure after removing the SiO₂ sacrificial layer with a 5000 lines/mm grating. The results demonstrate the feasibility of this method.

A new phase shifting SEM scanning moire method is proposed in this paper. The phase shifting technique is realized in four steps from 0 to 2 π by shifting electron beam in y-axis direction controlled by SEM system. It is successfully applied to measure the virtual strain of a MEMS structure with grating of 5000 lines/mm. The experiments prove the technique can be widely used in meso-deformation measurement, and also show the sensitivity of experiments is highly improved after phase shifting technique. It provides a new way for disposal of fringes patterns in sub-micro moire method.

This paper introduces how to in situ observe fracture behavior aroung a crack tip in ferroelectric ceramics under combined electromechancial loading by use of a moire interferometry technique. The deformation field induced by electric field and stress concentration near the crack tip in three-points bending experiments was measured. By analyzing the moire interferometry images it is found that under a constant mechanical load, an electical field has no effect on crack extension in the case that the directions of the poling, electric field and crack extension are perpendicular to each other. When the poling direction is parallel to the crack extension direction and perpendicular to the electric field, strain decreases faster than values predicted by the theoretical analysis as the distance away from the crack tip increases. In addition, as the electric field raises the strain near the crack tip increase, and the strain concentration phenomena becomes more significant.

In this paper, moire interferometry method is applied tostudy interfacial fracture behavior analysis of Porcelain-Fused-to-Metal restoration. The SIF with respect to the crack of four-point bending specimens are studied by moire interferometry. The Carrier technique is applied to get the phase and displacement of the interfacial crack. The SIF is attained by the method of this paper. The experimental result proves the moire interferometry method can be applied to the small specimen with the interfacial crack.

In the present paper, a method for measuring the shear-stress distribution over a solid surface in a fluid flow is studied with a use of shear-sensitive liquid crystal coating. The color response of the liquid crystal coating is calibrated against the various shear stress magnitudes and directions using an experimental test section of laminar channel flow. The measurement of shear stress distribution is carried out with a use of two color CCD cameras situated side by side. The color to shear stress transformation is conducted by the analysis with use of relative hue as a calibration variable, which is a function of shear stress magnitudes and directions. The usefulness of this technique was confirmed by the measurement of shear stress distribution around a circular cylinder with small span.

The most important procedure for improving accuracy of modeling in stereo-lithography is to clearly identify the relationship between the conditions of laser irradiation and the solidification of photo-curing resin for modeling. The parametric study concerning laser power, laser beam diameter, laser scan speed and properties of photo-curing resin was conducted in order to find those influence on the dimensional accuracy of the solidified resin.

An optical diagnostic system consisting of the Michelson interferometer with the image processor has been developed for the study of the kinetics of the thermal capillary convection. The capillary convection, surface deformation, surface wave and the velocity field in a rectangular cavity with different temperature's sidewalls have been investigated by optical interference method and PIV technique. In order to calculate the surface deformation from the interference fringe, Fourier transformation is used to grating analysis. The quantitative results of the surface deformation and surface wave have been calculated from the interference fringe pattern.

This paper presents applications of LIF in the flow of high temperature and high enthalpy gases: we have adopted ArF excimer to excite the rot-vib absorption lines near 193.3 nm for Schumann-Runge system of Oxygen and used UV PMT to detect the fluorescence near 256nm to establish a set of LIF flow field measuring system based on ArF excimer. On the basis of LIF system we have done some research on LIF technology. We have obtained the experimental results of fluorescence signal within Oxygen Schumann-Runge system for the air at room temperature and arc-jet of oxygen and argon mixture gases. The experimental result show that the LIF measurement system based on ArF excimer has been established successfully.

Planar Laser Induced Fluorescence (PLIF) technique was utilized to measure the image of hydroxyl radicals (OH) fluorescence and spontaneous emission in hydrogen/air and kerosene/air supersonic combustion. The results showed that PLIF has been an efficient approach for identification of fuel/air mixing and combustion process. It was found that large number of OH radical is concentrated in the cavity range of the combustor, it is helpful to understand the mechanism of the cavity as the flame-holder in supersonic combustion.

It is well known that arc plasma is one of the main tools for the ground simulation of the reentry environment, so its experimental diagnoisis is very important. We have etsablished a set of arc plasma supersonic nozzle flow device with high stability and running continuously. The stability of spectral intesnti for supersonic arc-jet is 1-1.5%. On the basis of the device we have made a spectroscopic diagnostic investigation on the supersonic nozzle flow of non-equilibrium arc plasma for argon arc-jet and obtained the rich experimental diagnostic results about supersonic arc-jet. The experiments results show that the electron temperature of supersonic arc-jet changes non-monotonically, and it decrease in a range and increases in the next range periodically along with the flow direction. The established device and diagnostic method on supersonic flow of arc plasma has a very wide application in the research on non-equilibrium flow mechanisms of high temperature gases.

The Optical Pressure Measurement (OPM) technique is a kind of practical pressure measurement in high-sped wind tunnel. The pressure data on the wing surface of an airplane model by both OPM technique and clasic tap measurement technique in high-speed wind tunnel are given in this essay. The FOP-1 paint made in china was used in the OPM technique. The measuring results with the two techniques are discussed, and the performance of FOP-1 paint is proved to be good.

By means of Hartmann Sensor at the rate of 419 Hz, a series of dynamic degraded wave front of collimated laser transport perpendicularly across a heated air flow was measured. The airflow was generated using a vertical-placed nozzle. An integral result of the airflow density distribution was educed. Both span-wise direction and stream-wise direction structure convection were observed. Some pilot study of flow field visualization was made.

One new kind of the laser-ultrasonic technique in which a continuous ultrasonic signal is used to record flow-induced traveling time differences of ultrasonic wave, propagation along a measuring sound beam between two laser beams, so-called A Continuous Ultrasonic Signal Method of Laser-Ultrasonic Technique, is presented. This method allows a fast and non-disturbing exploration of the flow field around models in wind tunnels. By using the new method, even an ultrasonic transducer with lower performance could be employed, and there is no need a high-accuracy optical detector.

Sensors and actuators become much smaller as parts of MEMS devices. Some of them run based on the thermal principle and thermal characteristics directly determine their performance. For example, micro-hotplate structures are incorporated into integrated gas sensors to heat the sensing thin film to a determinate temperature with a high sensitivity. The micro-machined accelerometer with no proof mass is based on free convection of a tiny hot air bubble in an enclosed chamber. The temperature profile of its heater is a key factor influencing the feature of the accelerometer. A thermally actuated membrane micro-pumpo can drive fluid by periodical heating of materials with different thermal expansion coefficients and consequent periodical vibration. An IR thermography with a microscopic set was applied in their thermal measurement to optimize these devices.

In this paper, digital micro-speckle correlation method is used to calculate strain field of functionally gradient material (FGM) in constant temperature, and the results are compared with that of double layer material in constant temperature. This paper offers a kind of feasible experiment method and meaningful results to design and prepare functionally gradient material. The experiment shows that the FGM can relax effectively the stress between any two laminates.

In order to solve the problems that exist in the magnetic liquid seal of reciprocating shaft, we have set up an experimental facility, which composes a camera, a microscope, a step-by-step motor, a pin roller screw, a reciprocating motion shaft, pole pieces, a permanent magnet and the magnetic liquid in the seal gap. Through the optical technology and image process of the experimental facility, we have studied the magnetic liquid flow in the seal gap when the reciprocating shaft moves with different velocities and strokes, this study especially concentrates on 1) the regular pattern of such flow; 2) the loss quantity of magnetic liquid caused by the reciprocating motion shaft; 3) the failure reasons of this magnetic liquid seal and 4) the design of a new structure for the magnetic liquid seal of reciprocating shaft. The application indicates that the new structure is very effective in some occasions.

A method was developed to determine the petroleum coke particle size in illuminant flame by a laser-Doppler velocimeter. The particle size was determined by taking the wave number into account in addition to the pedestal amplitude. The petroleum coke particles were blown into the vertical test pipe from the lower part of the pipe and were heated to 850° C by electricity. The measurement points were at the 50 mm, 450 mm and 900 mm up the pipe entrance. The measurement result shows that there was obviously particle size enlargement at the process of the burning, and there was not obviously crash phenomena at the process.

The shift step must be an accurate value in the traditional algorithm of phase-measuring profilometry technology, the result error is found in unequal step-shifting in which one or more step is not the accurate value. So the phase shifter is expensive to meet the high precision. In this paper, the software is made to give a chart of error phase in any unequal step phase-shifting, and a calibration algorithm is presented to give the correct phase based on this error-phase chart. With the help of computer emulator written by us, the calibration algorihtm based on checking proved to be correct. So the precise request of phase shifter is reduced greatly.

In 3D projecting grating profilometry, we are often persecuted by some disgusted phenomenon of images, such as reflecting flare, overlapping of grating and other noise. All these can bring a bigger error in image processing. The intention of this paper is to propose some special filter and other methods of image processing. The technique we applied is based on peculiarity of projecting grating profilometry image, which has obvious directionality. We used the nonsymmetrical multi band-pass filters to reject the high frequency noise along the grating and other component except base frequency part. The result obtained from the processed image by multi band-pass filter is much better than that from primary image. The method is propitious to measure some smooth surfaces.

Study on the mechanical behavior of FRP-concrete structure is mainly by means of theoretic calculation and experimental analysis. Comparing with the electrical strain gauge which are generally used to measure the external strain for short term, fiber optic sensor which is embedded in the interface of FRP tube and inner concrete, can easily not only measure the internal strain of the structure, but also monitor the crack expanding of inner concrete. The Mach-Zehnder interferometer is applied in the strain measurement. The optical parameter of fiber optic sensor is identified in the calibration experiment, so the internal strain can be calculated by processing the experimental optical signal. The method of automatic data collection and signal processing of the measuring system is presented in the paper.

A digital image correlation system, which is a combination of a long-focus microscope and a digital image-measuring device, is developed for study in the mechanical behavior of the viscoelastic materials. In this paper, the precision of the digital image correlation system is assessed by using an extra solution within of the framework of infinitesimal strain in particular, the choice of the size of subset in the correlation technique is discussed when the displacments are not infinitesimal. Then, the system is employed to obtain the displacement field in each step, strain field in the interest area of the specimen, and the experimental result show that digital image correlation system can perform the precise measurements of the mechancial behavior of viscoelastic materials.

It is dificult to analyze fringe pattterns by phase-step technique because of the unstable fluid field when employing shearing interferometer to measure the temperature-gradient field of free convection. To overcome this difficulty, a new method is presented to proces the carrier fringe patterns. The fringes before and after disturbance are thinned to locate their centers and encoded into numerical data. The value of firnge order on every pixel can be acquired by surface fitting to these data. By subtracting the two fringe fields, the fringe order distribution caused uniquely by the temperature change can be obtained. This method can also eliminate the aberrations of the optical system. The method is applied to this recent experiment to obtain new results.

The surface profile is presented various, that forming cause of the specific trace is different. The specific trace is distributed as two types, from its criterion. First, the criterion of the specific trace is large, surpass a millimeter, is called grand specific trace; Second, the criterion is small, more or less the same length micron, is called micron specific trace. Using projection, contracting beam micrography, two-dimensions adusting image mode exchange, low-pass filter off noise, wavelet, and intelligent mode phase reconstruction, the surface profile of recognizing specific trace is given exactly and rapidly, that is a new optical image processing technology in recognition and diagnosis. This paper introduces the speciality above the technology and gave typical examples.

In the particles' size optical measurements, the distribution of particles' size is often caculated upon the diffraction image, so the quality of the image is very important. But in the real case, information data of the image both in high bright area and consulted area are often lost because of the overflowing of zero grade diffraction stripe and submersing of high grade diffraction stripe, but for the disfigurement of optical element, speckle and system accepting-error. In this paper, a new method of double filter data processing is put out, that is, the image is first divided into some net-section, the integral-average of scattering energy in this section is chosen as a rebuilt data, and second, non-linearity alternated processing is put out to reduce the trouble affecting and with in the probability idea the probability brightest dot data is set as 1, the backdrop probability data as least at the proejcted section. At last, a high qualty image is rebuit in 3D with this two filter processing after processing by a computer.

Surface Plasmon Wave Sensor (SPWS) is a new type of sensor. Many output light measurements of SPWS exist, such as to measure the single color light intensity, to measure the absolute light intensity spectral and to measure relative light intensity spectral. In the paper, several ways to measure and analyze the outputs light of the SPWS are presented. In particular, absolute light intensity spectral analysis and relative light intensity spectral analysis are contrasted. For the way to measure the absolute light intensity spectral, it requests that the input light must be an ideal white light and has very steady light intensity. For the latter way, it needs not the same requests as the former. So the input light has little influence on the measurement and the relative light intensity spectral has much merit such as the low request to input light, higher precision etc. At last, we obtain a conclusion that it is most adaptable to use relative light intensity spectral analysis to measure the output light of the optic fiber SPWS.

Cost-effective and reliable damage detection is critical for the utilization of composite materials. This paper applies a new combined method of Kohonen self-organizing feature neural networks and active damage detection technique to composite health monitoring. The proposed method features a simple structure algorithm, supervision free self-study and lateral association, etc. According to such method and virtual instrument technique, an active damage detection system for composites is developed. This effective method for damage detection has been verified in the course of its practical use.

According to the digital correlation of computer image processing, this paper advances a new high precision and un-touched method for measuring the large range distance by correlation search. In factual application, this method is used for measuring the distance of the CJ6120LC6HK carriage's front and trailing axes centers. This paper presents analysis on the correlation function, measuring precision and measuring error. Based 1m high precision mir, accurate orientation has been given, so that the good results have been gained for measuring the distance of the CJ6120LC6HK carriage's front and trailing axes centers. In conclusion, a good method for measuring the large range distance could give the revelation to the engineering application.

It is very important to explore yielding, opening and developing of the crack in contact fatigue failure problems in order to understand the theory and increase the lifetime of machine parts. The numerical methods, such as finite element method are used in solving the contact problem, but for the complex bound condition and stress concentrated area the methods are limited. The scatter photoelasticity is a power tool in solving the contact problem as it can obtain the stress components and find the 3D effect conveniently and nondestructively. In order to obtain the phase value from the isodyne image with unknown order fringes accurately and automatically some isodyne image distinction methods have been developed. In this paper the frequency domination isodyne method is applied in a contact problem.

Poly(3-hydroxybutyrate) exhibits remarkable embrittlement upon storage at room temperature, and this problem limits its widely use in technical purpose. In this paper, morphology and micro-structure of PHB spherulite are investigated by using the twelve variables gradient method and polarization microscope. The results indicate that the PHB spherulites could continuously crystallize, namely: secondary crystallization, the morphology and micro-structure of PHB spherulite are changed, the embrittlement at room temperature was resulted from PHB secondary crystallization. Competition phenomenon in the process of PHB secondary crystallization was found.

Interferometric reconstruction of a flow field usually consists of three steps. The first is to record interferograms, the second is to extract phase information from interferograms and the final is for numerical inversion of the phase data. In interferometric flow recording, test section enclosures and opaque models are frequently present, blocking a portion of the probing rays or restricting the view angle of the field to produce a partial data set especially for interferometric tomography. It also involves very harsh environments with external vibrations and disturbances of the ambient air. The ill-posed problem is susceptible to experimental noise and can produce serious distortions in reconstruction. Interferometric reconstruction of flow fields thus needs accurate phase information extraction. The major problem encountered in interferometry is that it is extremely sensitive to external disturbances including the vibration of the optical setup. This is true especially for aerodynamic wind tunnel testing. For successful application of interferometry to experimental fluid mechancis and heat/mass transfer, efficient mechanisms for accurate flow-field recording and information extraction are thus very necessary. In interferometric recording, use of the phase stepping techniques is desirable whenever possible, since they provide the most accuracy. However, they are not applicable under disturbing conditions; that is, under harsh environments. In an effort to provide accurate interferometric data, we device interferogram recording and reduction techniques. They are based on a phase-stepping method: however, applicable to harsh environments including wind tunnel testing. Here we present the governing concepts, investigation results, and application demonstration of our approaches for practical flow measurements. The developed approaches are tested through phoase extraction and 3D reconstruction of an experimental flow field, which is designed for future wind tunnel testing. The test conditions are very harsh, involving building vibrations and ambient air disturbances especially during the interferometric data acquisition in the phase stepping process. The results of the thermocouple readings agree fairly well with those from the experiment when compared. The acceptable error in the entire interferometric reconstruction process is believed to be mainly due to the ill-posed nature of the tomographic reconstruction but not from the phase extraction of the employed phase-stepping technique.

Several photos of projected gratings patterns should be taken from different angles, when 3D topography of revolving objects is measured by grating projected method. How to combine the measured data of grating projected patterns is a key factor of measuring 3D topography of revolving objects. A new data combination method, which is based on cylinder coordinate transform, is proposed in this paper. The equations and operating steps are introduced and the experiments are given in this paper. All the projected gratings patterns are processed by FFT phase technique.

A new reconstruction algorithm is presented, which transforms the plane image function into 2D Fourier series expansion and substitutes the projection vector of 2D Fourier series' orthogonal basic functions for that of the image function. By the minimum norm optimization criterion, the weighting coefficients are worked out and then the original image function can be obtained by inverse Fourier transformation. Computer simulations are made. The results show that the reconstruction time is less than one second and the maximum error can be less than 5%, the average error less than 1% by choosing proper approximation level.

Axisymmetric density field of the blunt cone model is measured in the free-flight ballistic range utilizing holographic interferometry. The paper introduces a new method that compared with the experimental interference fringes and the computational one for increasing the definition of reading interference fringes. A rebuilt technology for density field is used to obtain the full flow field density distribution that provides an experimental basis for model design and CFD. It is also significant to put the CFI technique further forward.

In present study, a novel method of reconstruction and fabrication of a missing external ear is developed based on laser scanning technique and CAD/CAM technologies. Using the method, the prosthesis of an ear has been fabricated and applied in clinic successfully. The precision and efficiency of rehabilitation reconstruction is improved. The results suggest that the dimensions of the contralateral ear, its position and the shape of the deficient side of the face can be reliably measured on the patient and that laser scanning is useful technique for planning and monitoring facial reconstruction of the ear and other apparatus.

Out-of-plane displacement of the electronic package is an essential source of the electronic device failure. It is caused from the mismatch of the coefficient of thermal expansion among different parts of IC device. Here a projection Moire system is presented for monitoring and analyzing warpage during packaging. Projection Moire is particularly useful to measure warpage of surfaces with components. While this method shows promising features, it will give erroneous results if improperly used. In this paper, the formula of the systematic erro is deduced. Based onteh analysis, compensation could be done to eliminate the systematic error and guarantee an accurate measurement results.

Super elastic single crystal CuAlNi is one of the most popular shape memory alloys in the world. It has been widely used in engineering, biomechanics and medical science. But some of its basic properties such a martensitic transformation of CuAlNi single crystal under compression and also their generation, nucleation and propagation of transformation band are not competely investigated. Its mechancial properties of CuAlNi single crystal under compression are also not investigated completely. The deformation of CuAlNi shape memory single crystal is reported under compression loading for selected crystal orientation. The stress-strain curve is obtained when it is compressed. 2D microscope images of martensitic band are also observed clearly with special method. The deformation of CuAlNi shape memory single crystal of stress-induced martensitic transformation under compression was firstly studied by using IR camera. It demonstrates that the transformation band also exists under compression.

The paper introduces the quantitative investigation of free-flight axisymmetric density field by laser holographic interferometry in physical range in CARDC. The free-flight flow field holographic interferogram and shadow picture of a sphere of 12mm in dia. at M=15 have been given. At the same time, the experimental result is compared with the computational flow field interferogram obtained by CFI. In the end, the quantitative gas density distributions and the separate distance between the bow shock wave and the sphere have been obtained.

The flow field of shock wave passing through curved channel and surrounding hill is investigated in a shock tube by holographic interferometry along with the quantitative measurement of the pressure distribution on the 3D object by transducer pressure measurement technology. The test results indicate that the effect in the flow field of shock wave is the largest at the copulation of 3D object and hill, the object leeward surface and its corner. It is significant to research into impact effect of shock wave at the complicated landform.

A system of nondestructive testing (NDT) with ability of automatic wide audio frequency scanning loading by use of electronic shearing speckle pattern interferometry is developed. Automatizaiton technique is used in the system of NDT.

A method to measure the 3D movement and attitude of a moving object based on the theory of optical measurement is introduced. In order to measure the 3D movement and attitude of a moving object, the method uses cameras to take image sequences of the moving object and extracts the information of the moving object in the images. The extracted information mainly consists of the object edges and the cooperative man-made marks, such as ellipses, lines, angles and the ratio of length over width etc., instead of points in traditional methods.

The paper presents a detecting method for oil tube thread, which combines optical techniques and image processing techniques to measure the physical dimension of tube thread and give further analysis. The relevant technqiues such as projection of tube thread, feature of thread image and image processing are discussed, the way for thread image measuring and calibration is introduced in detail. The measurement accuracy is also considered. Finally the application of the measurement is illustrated.

Observing turbulent boundary layer with Lagrange DPIV system composed of DPIV and moving equipment in which CCD camera displaced along to down stream of the flow; analyzing the factors of moving equipment conducing to measurement random error, deducing the expressions of random error; analyzing the measurement result and obtaining the primary quantitative result.

This paper discusses major challenges and resolution means of density field measurements by optical interferometric tools in the productive wind tunnel with larger test section dimensions. The application field of 3D density field interferometric measurement is presented in the blow-down facility. The experimental data error reduction is also analyzed in more detail.

Pulsed laser beam with lattice distribution was used to modify surface processing for ductile iron. The microstructures around the graphite were observed using OM, and Nanoindentation and micro-hardness of that measured from surface to inner of sample. The result shows that the graphite ball has an important effect on cow-eye microstructure evolution either in light molten area or in phase change hardened are. It is not true that assuming the material is uniform during laser rapid heating and fast cooling for the graphite ball as a dependant composition phase. The microstructures of cow-eye is made up of fine remnant austenite in light molten area, and consisted of martensite and bainite in laser modified are. The cow-eye microstructure has a transformation from martensite and bainite to pearlite with the distance increasing from surfce. At last, the microstructure evolution of cow-eye has been discussed.

In this paper, the methods of photoelasticity and image processing are used to study the formation of crack on reaction cylinders in a chemical factory and to evaluate its safety. As a result of studying, the reaction cylinders are safe under normal operating conditions, and can continue to be used, except the cracked cylinder.

The movement parameters of a wing of a flying airplane are important for its design, analysis and life-estimation, while the 3D measurement of these parameters is a difficult task. A measurement setup is proposed as well as its corresponding calibration and image processing algorithms to fulfill the task. The calibration methods for the camera system on both ground condition and air condition are developed. We present a new method of location of 3D straight line through plane-plane intersection. The results show that the 3D measurement accuracy in the difficult air condition can be better than 1mm.

An optical diagnostic system designed for the microgravity experiments on Marangoni drop migrations has been depicted in the presented paper. One part of the optical system was used to image and record the drops tracks; the other part was an equal-thick interferential system, it has the ability to observe the fine structures of the drop migrations. Some ground-based experiments had been performed and the results were simply discussed in the present paper.

This paper focuses on the steel strain measurement technics inside of steel reinforced concrete (SRC) by fiber Bragg grating sensors (FBGS). The technics include the stickup methods of optical fiber to steel and the connection design of imbedded FBGS with the external measurement systems. The traditional resistance strain gauges are also used to detect the internal strain for the comparison with the FBGS to validate the effectiveness of the technics. Two kinds of experiments were designed to deal with the problem the internal steel strain measurement with both effects of temperature and transverse strain on measurement result of FBGS on the concrete beams. The epxerimental shows that the technics introduced in the paper can protect the otpical fiber from being broken during the manufacturing of SRC and make the internal strain measurement effectively by FBGS.

A measurement system on how to obtain the dynamic properties of rotor under the rotary condition using the laser untouched method was presented in this paper. This system mainly consists of three parts: laser vibrometer used to acquire and process signal from the rotor, gearing used to dive the rotor to simulate its real movement condition, and the rotor representing the measured object. In order to evaluate this system, the rotor was investigated under three states: hit by hammer, turned by hand, and turned by gearing in low speed. Showing from the measurement result, the measuring results of dynamic properites of the rotor under these three states were consistent. Consequently, the measurement system we designed is reliable.