Vortical flow field investigation using a two-component pressure sensitive paint at low speed

A two-component pressure sensitive paint has been designed to perform wind tunnel tests in low speed flow. In order to increase the measurement accuracy, the sources of errors have been reduced by using a low temperature sensitive paint. Furthermore, this PSP allows to measure the variations of the excitation light between wind-on and wind-off images by means of the second component, insensitive to pressure. The PSP is applied on an non-instrumented delta wing model and pressure data are obtained by using separate calibration on small samples of paint. PSP images present some defects of non-uniformity due to a problem with the paint itself. Pressure fields are obtained from 50 down to 24 m/s. Comparison between measurements obtained with pressure taps and PSP results on separated tests shows a significant shift due to the paint calibration.