HU Chujun, AN Qianglin, WANG Xiaocheng
In this paper, a new model for calculating shipboard helicopter's landing operating envelope at forward fight condition is established by means of the momentum-source CFD method. In the new model, unsteady Euler equations in inertial coordinate system are used as governing equations, finite volume method (FVM) is employed in spatial discretization, and a five-stage Runge-Kutta explicit time iteration algorithm is adopted in temporal discretization, which all can help well simulate the rotor/fuselage/ship coupled aerodynamic characteristics in a complex turbulent flowfield environment during landing on the ship. To improve efficiency significantly, momentumsource model is chosen to represent the effect of rotor on its flowfield. In addition, the helicopter's trim calculation is also considered determine the operating envelope. Then, a Helicopter UH-60 is selected as the research object, and the wind azimuths of 0, 60 and 300 degrees are chosen for trim calculations. By using the available test data, the capability of the present trim method combined with CFD model is examined. With this method, the sample helicopter's landing operating envelope is calculated based on the judging criteria determined by the main rotor and tail rotor's control, helicopter's attitude angle and required power. Results show that the present method is suitable for determining shipboard helicopter's landing operating envelope.
