椭圆形控制环量翼型气动力的计算

A METHOD FOR CALCULATING THE AERODYNAMIC FORCES OF ELLPTICAL CIRCULATION CONTROL AIRFOILS

本文用边界层理论与计及分离尾迹影响的位流理论相结合的方法计算控制环量翼型的绕流,用离散涡模型模拟分离尾迹的影响。由上、下翼面分离点处引入离散涡。只是翼型附近尾迹中的离散涡可以自由移动。离翼型较远的离散涡假设为按来流速度移动。忽略射流出口上游的边界层对射流的影响。这些简化使本文的方法十分有效。与实验比较表明,本文的方法能较准确地计算出翼型的分离点位置和分离点前的压强分布。计算出的升力系数与射流动量系数的关系与实验相符很好。

This paper presents a method for calculating the aerodynamic forces of elliptical circulation control airfoils by combining the boundary layer calculation and potential flow calculation, and the effect of the separated wake on the potential flow is included using the discrete vortex method. Nascent vortices are introduced into the flow from the separation points on the upper and lower surfaces of the airfoil to model the separated vortex sheets. Only the vortices in the near wake are allowed to move freely and the vortices in the far wake are assumed to move with the free-stream velocity. The effect of the boundary layer upstream of the jet exit on the jet development is neglected. These simplifications make the present method very efficient. Good agreement between calculated and experimental results is obtained for the separation points and pressure distributions before the separation points, and for lift coefficient vs. momentum coefficient.