摘要
利用ESPI技术测量气流场的散斑位移,CCD快速采集热气流扰动的N帧时序散斑干涉图,采用序列相减或自动相减得到时序相关条纹,对相关条纹进行傅立叶变换、频谱滤波、逆傅立叶变换、三维相位展开,计算出气流快速变化过程中任意时刻物光的相位变化,并得出相位变化与气流场散斑位移和折射率梯度的关系式,也可再现气流场的变化过程,为热物理参数测试中的快速动态过程提供一种实验分析手段。
ESPI was proposed to test airflow speckle shift. N trames of speckle patterns along temporal sequence were collected by CCD, phase field of correlated patterns were obtained after calculating the temporal correlated patterns using a FFT program, which does Fourier transformation, filtering, inverse Fourier transformation and phase unwrapping. Then the instantaneous speckle shift could be worked out and the variation process of airflow filed could be also redisplayed. A new experimental analytical method for fast dynamic processes in testing of engineering themodynamical parameters was
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
北大核心
2006年第4期156-161,166,共7页
Journal of Sichuan University (Engineering Science Edition)
关键词
气流散斑场
ESPI
相关条纹
傅立叶变换
散斑位移
airflow speckle field
ESPI
contouring fringes
Fourier transformation
speckle shift
