Experiments were conducted on a 1:17 model-scale helicopter rotor hub in the Pennsylvania State University Applied Research Laboratory 12-inch diameter Water Tunnel. Qualitative methods were used to investigate the interaction between the rotor hub and a canonical engine pylon upper surface. Oil paint visualization showed flow separation on the engine pylon and a high degree of interaction between the hub and pylon flows. Fluorescent dye injection revealed significant differences in the unsteady flow character between advancing and retreating sides of the rotor hub. Stereo particle image velocimetry was used in the wake of an isolated hub configuration to quantify the spatial and phase-dependent variations in wake velocity, revealing a wake bias towards the advancing side and, unexpectedly, a phase-averaged unsteadiness bias towards the retreating side. In general, a previously unavailable broad view of the rotor hub flowfield was obtained.
All Science Journal Classification (ASJC) codes
- Computational Mechanics
- Mechanics of Materials
- General Physics and Astronomy
- Fluid Flow and Transfer Processes