Numerical Simulation of the Airflow over Complex Terrains at Low Altitude

In order to avoid the problems of existing methods, a numerical simulation method for two-dimensional airflow over complex terrains is developed in this paper for the engineering use of flight dynamics. Based on the potential flow theories, the effects of terrains on the wind field are considered by a serial of two-dimensional vortexes, whose strengths are solved by combining with the ground boundary conditions. Numerical examples are studied by the proposed method, and the method is also evaluated by comparing the results with ones from the existing method. The result shows that the two- dimensional profile of complex terrains could be described by a cubic spline curve precisely. The computation procedure proposed in this paper is very simple and efficient, and it could provide a result of wind field with considerable accuracy. Therefore, this method could be used for flight principle evaluation and flight simulators.