Temperature corrected Pressure Sensitive Paint measurements on a flexible surface
Michela Gramola, Paul J. Bruce, Matthew Santer
Abstract
View Video Presentation: https://doi.org/10.2514/6.2021-0128.vid The temperature sensitivity of Pressure Sensitive Paint (PSP) in supersonic wind tunnel experiments has been explored through diagnostic experiments on a flexible model and analytical predictions of its thermal behavior. A 3D flexible plate, clamped on all sides, was tested in the Imperial College London supersonic wind tunnel at Mach 1.4 and 2, with and without a shock wave. Point-tracking photogrammetry was employed in conjunction with PSP to facilitate image registration. A heat transfer solver was written in MATLAB to estimate the plate temperature during tests given its geometry and the flow conditions. Results from this were employed to investigate the impact of surface deformation, variations in tunnel stagnation temperature with time, step changes in plate thickness and Mach number gradients on the paint luminescent response. Temperature-dependent calibration coefficients were computed and applied to the different regions of the plate to account for local temperature differences during a test. This was found to significantly improve accuracy of the pressure measurements and remove non-physical features.