Image processing of PSP technique in the internal flow

Optical pressure sensitive paint technique is attracting extensive attention for its unique advantage at surface pressure measurement. However, the precision and display of the PSP measurement results are affected by the measuring difficulties caused by complex inner-flow and narrow measurable space. Based on comprehension of the measuring mechanism, image processing scheme is explored and optimized by adopting theory image registration and resection. Using Fortran language, 3D reconstruction of PSP technique is developed by authors. The developed PSP image processing scheme is verified by the PSP image of the NPU cascade. The PSP image on the suction surface of NPU cascade is transformed from 2D into 3D and compared with the results of the pressure scanner. The results show that the PSP image processing method in this paper is an effective means to increase the accuracy in the internal flow measurement, and it is easy to obtain the pressure distribution on a cascade by the image 3D reconstruction.