Vortex Generated Rotor Wake Model for Real-Time Simulation

A model of the wake of a helicopter rotor is presented that is based on tracking vorticity generated by the rotor blades. The blade elements are treated as lifting lines. The near wake is presented as a vortex lattice and the far wake as vortex rings. The velocity induced by all parts of the wake is used to compute the lift of the blade elements and to drift each part of the wake. A vortex lattice generated by ten rotor revolutions, with vortex rings representing older vorticity was sufficient to reproduce the full induced velocity at the rotor. Real-time operation was achieved with only tip and root trailing vortices accounted for, using 16 Pentium II processors in parallel.