Polarization imaging based supersonic/hypersonic flow field measurement method

Abstract

The invention discloses a polarization imaging based supersonic / hypersonic flow field measurement method. The method comprises the following steps: optimizing a line-biased laser light source for incident illumination such that the polarization degree of the incident line-biased laser is within a set threshold range; adjusting the polarization direction of the incident line-biased laser and the receiving angle of a polarization imaging system so as to make a scattering signal of nanoparticles at the imaging angle of the polarization imaging system strongest; using the polarization imaging system to image the supersonic / hypersonic flow field to obtain a polarization-related result of the scattered light signal of the nanoparticles, wherein the polarization-related result includes the polarization degree, the polarization angle, and the ellipsometric angle of the scattered light of the nanoparticles; and converting the density field of the supersonic / hypersonic flow field based on the polarization information to obtain density distribution of the supersonic / hypersonic flow field. The invention utilizes the polarization parameter information of the scattering signal of the nanoparticles to realize the visualization and fine measurement of the flow field, and has good anti-interference ability and high precision.

Description

technical field [0001] The invention relates to the technical field of flow field measurement, in particular to a method for measuring a supersonic / hypersonic flow field based on polarization imaging. Background technique [0002] The fine measurement of supersonic / hypersonic flow field is an important content of supersonic and hypersonic flow mechanism research. The aerodynamic performance of high-speed aircraft and the thermal protection of the aircraft surface are closely related to the supersonic / hypersonic flow structure outside the aircraft. It is necessary to study the flow structure through experiments to provide a basis for the design of the aircraft. [0003] Existing methods for supersonic / hypersonic flow structure measurement include schlieren, shadow, interference, particle image velocity field (PIV), filtered Rayleigh scattering (FRS) and laser-induced fluorescence (PLIF) and other methods (Fan Jiechuan. Modern Mobile Display Technology [M]. Beijing: National ...

AI Technical Summary

Problems solved by technology

[0006] The present invention provides a method for measuring supersonic / hypersonic flow field based on polarization imaging to solve the technical problem that existing NPLS technology tends to produce large errors in the quantitative measurement of supersonic / hypersonic flow field due to the inhomogeneity of light intensity

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