Application of a Real Time Free Wake Induced Velocity Model in a Naval Rotorcraft Flight Trainer

Accurate modeling of the aerodynamic and induced flow field in the vicinity of rotorcraft during naval operations is an important aspect in the development of high fidelity simulation and training models. This paper describes the development and implementation of a high fidelity, real-time, induced velocity software module for use in piloted rotorcraft simulations (trainers) to enhance the modeling fidelity for simulating shipboard operations. The core technology is built upon real-time solutions of full-span, free-vortex rotor wake models coupled with fast panel fuselage/empennage/ground plane models. This aerodynamics module provides a detailed prediction of the three-dimensional, unsteady rotor-induced flow field, including complex multi-rotor and wake/fuselage interactions, as well as full/partial ground effect for moving ship/landing platforms in challenging flight regimes relevant to shipboard flight operations. The induced velocity module has been integrated with the NAVAIR CASTLE/H-60 flight dynamics model and operated within the MH-60 MMH trainer to demonstrate the application of real-time free models in a prototypical trainer environment. Also described is the development of an innovative approach for coupling the free-vortex rotor wake model with CFD-based ship airwake models to allow a fully-coupled rotor wake/ship airwake free-wake solution in real-time.