Wind Tunnel Test Results for an Overlapped Quadrotor Configured UAS

The Aviation Development Directorate of the U.S. Army Aviation and Missile Research, Development and Engineering Center (AMRDEC), in cooperation with the U.S. Army Research Laboratory and the NASA Ames Research Center Aeromechanics Office, conducted wind tunnel tests of an Overlapped Quadrotor (OQ) configured UAS in the U.S. Army 7- by 10-foot Wind Tunnel at the NASA Ames Research Center, Moffett Field, CA. The OQ was one of multiple quadrotor aircraft that were tested in the 7- by 10-foot Wind Tunnel in January 2017. The OQ is a prototype overlapping, shrouded rotor, quadcopter aircraft that was developed by Malloy Aeronautics and modified by the Army Research Laboratory (ARL). A novel design characteristic of the OQ revolves around the arrangement of its rotors – pairs of diametrically opposed overlapping shrouded rotors are oriented in opposite directions and opposing geometric planes, while the overall thrust direction is uniform, achieved via pairs of counter-rotating rotors. The purpose of the test was to evaluate the aircraft performance over a variety of projected flight conditions, while also quantifying the aerodynamic interaction effects of an overlapping shrouded rotor design. The test is described here in detail, and a selection of the key results from the test is presented.