Flow measurement is the key method for R&D and operation monitoring of liquid rocket engine. Therefore, it is
important to measure flux of low temperature liquid propellants for the liquid hydrogen/liquid oxygen or the liquid
oxygen/kerosene rocket engine. Presently in China, the level meter and the turbine flowmeter are usually used in the
experimentation of the liquid hydrogen/liquid oxygen rocket engine. The level meter can only scale average flux and the
precision of the turbine flowmeter (the measuring wild point is 1.5%) can not be ensured due to the reason which there is
not devices of low temperature real-time demarcation in China. Therefore, it is required to research the high performance
low temperature flow measurement equipment and the vortex street flowmeter is selected because of its advantages. In
the paper, some key techniques of low temperature vortex street flowmeter are researched from the design aspect. Firstly,
the basic theoretical research of vortex street flowmeter includes signal detection method, shape of vortex producer and
effects of dimension of vertex producer to vortex quality. Secondly, low temperature vortex street flowmeter adopts the
method of piezoelectric components stress mode. As for the weakness of phase-change, lattice change and fragility for
many piezoelectric materials in low temperature, it can not be fulfilled piezoelectric signal and mechanism performance
under this condition. Some piezoelectric materials which can be used in low temperature are illustrated in the paper by
lots of research in order for the farther research. The article places emphasis upon low temperature trait of piezoelectric
materials, and the structure designs of signal detector and calculation of stress, electric charge quantity and heat transfer.
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