机身边界层控制研究

对带壁面抽吸的三维可压缩机身边界层控制进行了计算研究。采用了非正交曲线坐标系边界层方程,通过修改矢量流函数关系式,将壁面法向速度转变成为控制方程的一个可调参数,从而消除了边界条件与方程未知参量之间的非线性耦合;所发展的横向分段推进数值技术,可用于计算横流速度在横向多次反号的复杂边界层流动;设计不同的壁面抽吸系数分布,以研究边界层控制对多种边界层特性的影响。结果表明:壁面抽吸对边界层的控制效果是显著的,合理的抽吸分布能有效地减小机身阻力。

Investigation of Fuselage Boundary Layer Control

The three-dimensional compressible boundary layer flow for a general fuselage with suction is investigated computationally by means of the boundary layer equation for a nonorthogonal curvilinear coordinate system. The stream function is modified and the nonlinear interaction between the boundary condition and the unknown variables is removed through the translation from wall normal velocity to a adjustable parameter of the governing equation. In this paper a numerical technology of crosswise marching along divided segments is developed. It can be used to compute the complicated boundary layer flow in which the sign of the crosswise velocity is changed for many times. Several different suction distributions are designed and their effects on kinds of parameters of boundary layer are investigated. The results show that the effect of suction is obvious and the appropriate suction distribution can appreciably reduce the drag of fuselage.