Differential lnfrared Thermography (DIT) for Dynamic Stall Detection

Kurzfassung

Flow separation plays an important role in the aerodynamics of propellers and helicopter rotors. Although the ideal is to retain attached flow under all flight conditions, the main rotor of a helicopter sees partial separation under highly loaded forward flight or for flight conditions which include the blades intersecting their own wakes. The presence and position of flow separation on the blade is of great interest during its operation. The knowledge of the flow separation is needed for the performance assessment, for the validation of the design, and for the calibration of numerical transition prediction tools. The paper describes the first use of Differential lnfrared Thermography as a new method for dynamic stall measurements on pitching and rotating blades.