A Real Time Finite State Induced Flow Model Augmented with High Fidelity Viscous Vortex Particle Simulation

This paper describes a real time rotor induced flow model that was developed by combining the high fidelity viscous vortex particle method with the computationally efficient finite state formulation. The viscous vortex particle method (VPM) offers advanced vorticity modeling technology and the finite state rotor induced flow formulation is widely used for real time simulation. The viscous vortex particle simulation is able to capture the important physics involved with the complicated rotor vortical flow, such as the effects of vortex stretching and contraction and the effect of wake diffusion and decay. Through this research, a model augmentation technique was formulated that successfully derived the enhanced finite state rotor induced flow model from the viscous vortex particle method. The finite state model thus augmented was validated in real time by reproducing the results of the vortex particle simulation. The augmented finite state rotor induced flow model was also integrated with rotor dynamics and a full helicopter simulation and validated against measured data. Excellent correlation with the measured data was obtained for the predicted rotor induced flow, the rotor flapping dynamics, and the aircraft dynamic response.