用于层析粒子图像测速的模拟粒子场成像

Simulated particle field imaging for tomography particle image velocimetry

对层析粒子图像测速(PIV)技术中示踪粒子成像部分进行理论分析,并结合真实风洞的相应参数,通过搭建模拟粒子成像平台的方法来进行研究。设计了一套体积为80mm×100mm×100mm的激光照明系统,以提供粒子场的入射光强。建立了示踪粒子的三维成像模型,从而得到层析PIV系统的模拟图像。分析了影响PIV系统成像质量的相关因素。在单像素粒子数为0.007 7的情况下,通过真实粒子图像和模拟粒子图像比较,验证了该方法的正确性。

Tomography particle image velocimetry （Tomo-PIV） is a laser speed measurement technique that obtains a three-dimensional velocity field in a space. Based on the Tomo-PIV imaging theory, this paper analyzes the relation between optics model of trace particle imaging and the three-dimensional discrete projection method of CT image reconstruction. A new synthetic images computing method which corresponds to the real wind tunnel’s parameters are proposed. Then, a simulation laser illumination system with an irradiated volume of 80 mm×100 mm×100 mm is developed. The simulated Tomo-PIV images are obtained from the three-dimensional trace particles imaging model programmed by MATLAB. The factors affecting the imaging quality of PIV system are analyzed. Comparison of the synthetic images with the real particle images in which the number of particles per pixel is 0.007 7 shows the correctness of this simulation method.