New Computational Models for Airframe Aerodynamics In- and Out of Ground Effect

摘要

This paper describes a new aerodynamic model for the flow past a complete helicopter in a generic flight state, with particular reference to hover and forward flight in ground effect. The model is based on an unsteady Reynoldsaveraged Navier-Stokes code, coupled with a quasi-steady actuator disk and a blade element method for the rotor blades. The implementation presented does not require any changes in the computational grid. The effect of the rotor blades is included as a momentum source distribution. The disk loading is calculated with a convolution through a Gaussian function. Examples of results are shown for an airframe in hover out of ground and forward flight in proximity to the ground (ground clearance h/d = 0.8).