Incorporation of Vortex Line and Vortex Ring Hover Wake Models into a Comprehensive Rotorcraft Analysis Code

The incorporation of simplified hover wake models into the comprehensive rotorcraft analysis code C A M R A D is described and examples are given on their use. The axisym metric models, in which vortices are represented by either straight lines or rings, are a more generalized form of the free wake models of R.T. Miller at MIT, with the wake geometry also able to be prescribed. Incorporation has allowed access to the tabular representation in C A M R A D of airfoil section characteristics as functions of angle attack and Mach number, and has broadened the range of rotor wake models in the code to include a free wake hover model that does not have the convergence problems of the existing free wake model when used for hover. Keywords: Helicopter wakes; Hovering; Vortices; Helicopter rotor aerodynamics; CAMRAD mathematical model; Australia.