Vortex Generated Rotor Wake Model for Real-Time Simulation
The University of Alabama Flight Dynamics Laboratory (UA FDL) has been simulating helicopters since 1981. The real-time, man-in-the-loop, simulator was developed locally and is continuously being upgraded. The hardware, software, architecture and math models are all developed in-house by a team of faculty and graduate students. Since 1994, the UA rotor model has been Bladehelo  - a true blade model that numerically integrates the flapping motion of individual blades and the shaft rotation. The approach is physically based. Discrepancies are studied until they are understood. Bladehelo played a key role in the discovery of residual bending , . Bladehe!o uses rigorous dynamic equations for blade motion. There are no linearizations and no small angle approximations. The exact non-linear equations are integrated numerically. Current day computers, even modest ones, are equal to the task, and any labor spent on simplifying the equations is unnecessary and runs the risk of missing higher order effects like the one pointed out in reference [3). Until recently, Bladehelo was subject to two major limitations: 1. rigid blades and 2. uniform inflow. Both of these limitations have been removed. The present paper reports on the modeling of a dynamic, vortex-induced wake.