Comparison of LED and LASER based Lifetime Pressure-Sensitive Paint Measurement Techniques

Abstract

The lifetime-based Pressure-Sensitive Paint (PSP) measurement method has several advantages over the intensity-based method which is more commonly used in wind tunnel tests. This paper reports about a measurement that has been conducted in an industrial wind tunnel to compare LED (“modulation approach”) or LASER (“single-shot approach”) based lifetime PSP techniques and to find advantages and disadvantages of both techniques when operated in a large wind tunnel facility. For this type of measurements gated cameras and pulsed light sources are required. Both techniques were applied to a test in the Transonic Wind Tunnel in Göttingen. Measurements were carried out using both methods on the same model and the same PSP coating. For this test, PSP was applied on a delta wing model equipped with pressure taps and measurements were conducted at various angles-of-attack and Mach numbers. The results of each lifetime-based PSP system are compared against each other and to conventional pressure tap data.