差分干涉CT技术诊断激波管界面不稳定性  

Diagnosis of Richtmyer-Meshkov instability in shock tube using shearing interferometric tomography

作　　者：刘寿先[1] 陈光华[1] 黄文斌[1] 袁树云[1] 王德田[1] 李泽仁[1] 彭其先[1] 

机构地区：[1]中国工程物理研究院流体物理研究所,四川绵阳621900

出　　处：《强激光与粒子束》2012年第7期1555-1560,共6页High Power Laser and Particle Beams

基　　金：中国工程物理研究院科学技术发展基金项目(2009B0403041)

摘　　要：对差分干涉计算机层析技术诊断激波加载下气柱界面不稳定性的可行性进行初步理论和实验研究。针对有限投影数的联合代数重建算法,提出了一种新的投影矩阵计算方法,采用特定投影方向,各投影方向具有不同采样间隔。投影方向的对称性和投影线的规律性使计算过程大为减化。用该重建算法对气柱密度场进行数值模拟,结果表明4方向投影能够重建激波作用下气柱演化初期的体密度场,8方向投影基本能够重建演化中期的体密度场。用差分干涉系统对激波管气柱进行3方向诊断的实验结果表明,差分干涉计算机层析技术用于激波冲击下的气柱不稳定性密度场诊断是可行的。The paper presents the numerical and experimental study of shearing interferometric tomography for Richtmyer-Meshkov instability diagnosis.On the basis of simultaneous algebraic reconstruction technique（SART）,a method is presented to compute the projection coefficient matrix using specific projection directions and different sampling interval for each direction.The symmetrical projection and projection ray regularity simplify the computing process of the conventional SART.The reconstruction of the density field of a gas cylinder was performed.The numerical results show that four-directional computer tomography（CT） can reconstruct the density field in the early stage of evolution and eight-directional CT has the maximal error less than 17% in the middle stage of evolution.Three shearing interferometers were used to measure the gas cylinder density in shock tube from three different directions.The phase distribution deduced from the interferograms basically coincides with the theoretical prediction.The results of numerical computation and experiment indicate that shearing interferometric tomography may be a useful tool for the study of Richtmyer-Meshkov instability.

关 键 词：界面不稳定性 差分干涉 计算机层析 气柱实验 激波管 

分 类 号：O436.1[机械工程—光学工程] O351.2[理学—光学]