CFD Analysis of Quadrotor Biplane Tailsitter Hover-to-Cruise Transition

Among various UAV configurations, quadrotor biplane tailsitter designs are particularly promising due to their efficiency in both hover and forward flight modes. This study investigates the hover-to-cruise transition of the CRC-80, a scaled-up, 80-pound, pitch-controlled UAV, based on the CRC-10 developed at the Army Research Laboratory (ARL). A flight dynamics and controls model of the aircraft is developed and coupled with three different levels of aerodynamic fidelity: a dynamic inflow solver, a vortex particle method code, and a Reynolds-Averaged Navier-Stokes based computational fluid dynamics solver. The different aerodynamic models are used to achieve accurate and force-balanced transition flight simulations. Unsteady and quasi-steady simulation approaches combined with multi-fidelity analysis are used to determine the sufficient level of simulation necessary for understanding the aircraft loads and acoustics.