Experimental Investigation of a Linear Cascade with Large Solidity Using Pressure Sensitive Paint and Dual-Camera System

Pressure Sensitive Paint (PSP) technique has been increasingly applied to the experimental research of aerodynamics and thermodynamics due to its strengths of non-contact, high resolution results and large coverage area, etc. However, rarely has this technique been successfully used to the study of internal flow such as compressor cascade, since narrow flow passages would heavily restrict the acquisition of PSP images. In this paper, PSP technique was used to study the pressure distribution on a linear compressor cascade with large solidity of 2.3, where the view of recording camera can be heavily blocked due to adjacent blade surfaces. To help get integrated PSP images of the internal flow passage, dual camera system along with image processing tools like 3D reconstruction and image integration were adopted. The results showed that with the aid of such assistance, image results with good quality and readability could be obtained. Meanwhile, pressure data given by PSP were compared with data from traditional way of pressure taps and showed good consistency. Massive results of the entire cascade passage surface were given with different inlet Mach numbers and incidence angles. The results showed that PSP technique can integrally measure cascade tunnel of large solidity with the help of dual-camera system.