Heat transfer measurements with fluid crystals at the Goettingen wind tunnel

Fluid crystals are used to investigate heat transfer in the fin region of an aircraft model tested in a wind tunnel at Mach 6. The fluid crystal method is useful in the qualitative determination of positions of high heat stress (hot spots) and in quantitative heat transfer measurements particularly with complex temperature distributions. Flow around the test model is free of disturbance for the noninstrusive method of measurement. Evaluation of the fluid crystal measurements is performed with a digital interactive image evaluation system (DIBIAS) and temperature distributions are illustrated.