Boundary‑layer transition on a rotor blade measured by temperature‑sensitive paint, thermal imaging and image derotation

Kurzfassung

Transition measurements using temperature sensitive paint (TSP) and infrared (IR) imaging are shown for a model-scale rotor blade using deblurring by an axial rotating mirror. The effective angle of attack was computed from the geometric angle of attack and the downwash measured using particle image velocimetry (PIV), and this agreed well with actuator disc computations. The transition locations extracted from TSP and IR agreed well, and also agreed with predictions from an Euler- boundary layer code with an envelope-e^N transition prediction.