First-Principles Physics-Based Rotorcraft Flowfield Simulation Using HPCMP CREATE-AV Helios

The flowfield around a helicopter's spinning rotor, whether in forward flight or hover, is difficult to model due to the presence of unsteady flow and strong vorticity. Unlike a fixed-wing aircraft, which leaves its deposited wake behind it, a helicopter flies completely within its own strong vortex wake system. In hover, the strong tip vortices coil beneath the rotor and significantly alter the rotor's aerodynamic performance. In forward flight, the rotor-vortex wake is swept back to the tail, causing unsteady flow that affects control and vibration. The underlying issue in modeling rotorcraft flowfields is the need to correctly account for the complex vortex wake produced by the rotor. This article outlines the historical progress of first-principles physics-based predictive tools, from early estimations to the current state-of-the-art coupled computational fluid dynamics models used today in the HPCMP CREATE-AV Helios code.