论文部分内容阅读
针对瞬态脉动流场光学传输效应的实时仿真问题,提出了基于数字混沌系统的脉动流场成像仿真方法。首先,依据湍流的三重分解理论,将脉动流场分解为拟序场和完全随机场;其次,通过数字混沌系统产生球涡来模拟拟序场,使用光线追迹方法得到拟序场的等效相位差;然后,使用混沌系统产生完全随机场的等效相位差;最后,利用拟序场和完全随机场的等效相位差构建脉动流场的随机相位屏,采用物理光学方法得到脉动流场的点扩展函数(快照图像);从而获得短(长)曝光图像序列。仿真实验结果表明:该方法得到的结果与风洞实验数据相吻合。通过修改相关参数可以方便地仿真不同条件下的湍流场的光学传输效应,为气动光学效应的测试和校正提供了一种新的方法。“,”For the real-time simulation of the aero-optical transmission effect induced by the instantaneous fluctuation flow field, a novel method based on digital chaos was proposed. Firstly, the fluctuation flow field was decomposed into coherent structure field and completely random field according to the triple decomposition theory of turbulence. Secondly, Spheres generated by digital chaos were placed randomly throughout the volume with a chosen size distribution to represent one realization of the coherent structure field, and then the optical path length was calculated for all rays to produce the phase change. After that, the phase change of the completely random field was created by digital chaos. Finally, the random phase screen of the fluctuation flow field was reconstructed with the phase change of the coherent structure field and the completely random field, and physical optics method was adopted to get the corresponding point spread function (snapshot image), and so on to produce a large number of short-term and long-term sequence images. The simulation experimental results show that the method is in line with the wind tunnel experiment data. The method can simulate the aero-optical transmission effect under different flow conditions by adjusting the relevant parameters, and provides a new approach to assess and correct the aero-optical effects.