Experimental Investigation of Wing-on-Rotor Effect at Low Disk Loading and Reynolds Number

Abstract

Hover performance and prediction for tiltrotor-like vehicles lack experimental data and computational models for rotor–wing interaction at low disk loading and low Reynolds number. An experimental investigation of rotor–wing interaction in hover near the small unmanned-air-vehicle scale (disk loading and ) is conducted to determine how changes in rotor–wing geometry influence rotor–wing interaction. The test setup consists of a rotor and a flat plate representing a generic wing. The vertical and chordwise distances between the rotor and the wing are varied to assess wing-on-rotor influence. Rotor thrust and torque, wing download force, and wing surface pressures are collected and analyzed. Trends and empirical equations are presented and discussed in the context of momentum theory. Results show that the increase in the wing download force is greater than the increase in the rotor thrust as the rotor approaches the wing. The effect is more pronounced as the disk coverage increases. The resulting empirical equations provide a preliminary estimation of rotor thrust and download force for arbitrary rotor type, disk coverage, and height in rotor–wing interaction at low disk loading and low .