Dynamic engine model integrated in helicopter simulation

An extensive physical based engine-governor-drive train model is integrated into the DLR helicopter simulation code SIMH. For that purpose, the main rotor formulation comprising rigid lead/lag and flap degrees of freedom is resolved for rotor speed and drive train dynamics. Parameterized engine and governor models are evaluated from complex high order physical descriptions, using reduction schemes, while still being physical meaningful, allowing for application in real time conditions. The full non-linear formulation is appropriate for the use in ground based simulation, allowing to cover the whole helicopter operative flight envelope. The parameters of the reduced lower order models were optimized by comparing the simulation results with BO105 flight test data in hover and forward flight. With the inclusion of both engine and drive train dynamics, improvements in the dynamic prediction of helicopter shaft torque, rotor speed, heave and yaw motion for collective and pedal inputs could be achieved.