Comprehensive optical diagnostics of complex flow fields

Gregory Toker; Daniel Levin; Alexander Lessin

doi:10.1117/12.281400

22 September 1997 Comprehensive optical diagnostics of complex flow fields

Gregory Toker, Daniel Levin, Alexander Lessin

Proceedings Volume 3110, 10th Meeting on Optical Engineering in Israel; (1997) https://doi.org/10.1117/12.281400
Event: 10th Meeting on Optical Engineering in Israel, 1997, Jerusalem, Israel

Abstract

This paper describes a series of promising optical diagnostic techniques to provide a comprehensive acquisition of the optical information from various flow fields under investigation. A simultaneous application of the two or even several diagnostic techniques which combines a CFD code calculations yield more accurate measurements of the density and/or the density gradient distributions in complex flow fields. Traditionally qualitative data of the density gradient in a high speed compressible flow have been obtained by schlierengraphy. A white light source and a laser two optical arms schlieren optical schemes were constructed on the base of a conventional schlieren system. The optical image of a model was focused on a photo film and projected on a screen. A CCD- camera was used to catch the focused image in real time, to display it on a control monitor and to record it on a video tape recorder. An acoustically stable holographic variable shear interferometer, which has been easily constructed on the base of the conventional schlieren system allowed to record a signal hologram during the wind tunnel run by using a continuous wave laser light source. Signal and comparison holograms have then been post-processed by the dual hologram technique to display shearing interferograms. A holographic Moire deflectometry method is presented. The holographic recording provides a 'freezing' of the distorted signal wave on a hologram to analyze it a posteriori by the Moire technique. A novel holographic Moire interferometer is described and its application to testing a small size axisymmetric supersonic air jet is shown. An interference method with enhanced sensitivity and compensating for optical aberrations, which is based on rerecording holograms is briefly described. It would provide a reliable acquisition of the phase information from wide range of weak phase objects including high speed low density flow fields. The method has been demonstrated by mapping the density field of the supersonic air jet as a representative weak phase object. The numerical analysis of a 2-D flow field was also carried out by means of computational fluid dynamics (CFD) methods.

Citation Download Citation

Gregory Toker, Daniel Levin, and Alexander Lessin "Comprehensive optical diagnostics of complex flow fields", Proc. SPIE 3110, 10th Meeting on Optical Engineering in Israel, (22 September 1997); https://doi.org/10.1117/12.281400

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available