等速上仰翼型绕流结构的数值模拟

NUMERICAL SIMULATION OF THE FLOW STRUCTURE OF A CONSTANT-RATE PITCHING AIRFOIL

通过数值求解涡量-流函数形式的N-S方程研究等速上仰翼型的分离流动结构。用ADI方法解涡量方程;用Poisson方程直接法解流函数方程。在计算得到的流场中除可看到实验中观察到的多涡结构外,还发现一些实验中未观察到的现象。将分离流动结构的计算结果与翼型气动力变化相联系,并结合涡动力学理论,定性地解释了上仰翼型产生高升力的原因。

The sparatated flow structure of an NACA 0015 airfoil performing the constant-rate pitching motion is studied by numerically solving N-S equations in vorticity-stream function form. ADI method is used for solving the vorticity equation and a direct method for Poisson equation is used for solving stream function equation. The computation correctly simulates the experimentally observed multiple-vortex structure on a pithching airfoil and, in addition, some new flow phenomena are revealed. Based on the calculated flow structure and existing data on measured aerodynamic forces, and by using the theory of vortictity dynamics, the mechanism of high-lift generation on the pitching airfoil is studied, and some ideas about it are provided.