Rotor Wake Study Near the Horizontal Tail of a T-Tail Configuration

Development of advanced rotorcraft configurations has highlighted a need for high-quality experimental data to support the development of robust and accurate analytical design tools. To provide high-quality experimental data, a test program was conducted in the NASA Langley Research Center 14- by 22-Foot Subsonic Tunnel to measure the flow near the empennage of a 15% scale powered helicopter model with an operating tail fan and a T-tail configuration. Three-component velocity profiles were measured forward of the horizontal tail for four advance ratios using laser velocimetry to evaluate the effect of the rotor wake impingement on the horizontal tail angle of attack