解极近水面飞行时全机气动力中水波效应的边界元法  

The Boundary Element Method (BEM) solving the water wave effect on the aerodynamics of a vehicle flying close to water surface

作　　者：邹光远[1] 谭华[1] 张立柱[1] 

机构地区：[1]北京大学力学与工程科学系,北京100871

出　　处：《水动力学研究与进展（A辑）》2003年第4期379-396,共18页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金 ( 195 72 0 0 2 )

摘　　要：本文以边界元法为基础 ,在线性水波的假定下 ,对贴近水面飞行的三维飞行器 ,提出了一种计算气动力中水波效应的方法。本文共分三部分 :Ⅰ .分析了用边界元法计算非定常压力分布的困难和产生这一困难的原因 ,指出了对非定常问题 ,强度分布函数解必须保证唯一性而不能差一个随时间变化的常数。为此对无穷远条件必须有一个正确提法 ,并在此基础上给出了克服这一困难的方法。Ⅱ .水波效应问题的数学提法 ,包括各种定解条件和解的最后边界积分形式 ,导出了在飞行器形成的压力场的作用下波高应满足的微分—积分方程 ,给出了求解的基本方法和步骤。Ⅲ .对于一个包含有复杂外形的机身、机翼、端板、垂尾和平尾的三维机型在贴近水面飞行时 ,作了包括水波效应在内的全机气动力计算 ,给出了水波效应随攻角、飞行高度、波幅、波长及波的入射方向等的变化 ,得到了有意义的结果 。This article expounds a method for calculation of the water wave effect on aerodynamics of a three-dimensional vehicle flying close to water surface. The method is based on the boundary element method, and under the assumption of linear wave. The paper consists of three parts: Ⅰ. Analyzing the difficulty in calculating the distribution of unsteady pressure when using BEM and the reason for it. We point out that for unsteady problem there can’t be a difference of an arbitrary function of time between the solutions of intensity distribution and the solution must be unique. So there is only one proper way to impose the boundary condition at infinity. On this, a method to overcome the difficulty is given. Ⅱ. The methematical description of wave effect, including all kinds of initial or/and boundary conditions and the final boundary integral formula of solution. We give the differential-integral equation that is satisfied by the wave height under the impact of pressure field generated by the flight. The basic solution method and the process of solution are also given. Ⅲ. Calculating the aerodynamic characteristics with the effect of water wave of an airplane. The airplane has a 3D complex shape and flies close to water surface. The 3D shape includes the body, the wings, the end plates, the vertical-tail and the horizontal-tail. The change of wave effect with the angle of attack, the height of the airplane, the wave amplitude, the wave length, and the direction of the wave are given. Useful conclusions are drawn. At the same time it is proved that the method of computing the distribution of the strength of unsteady vortex is correct.

关 键 词：近水面飞行 水波效应 边界元法 三维飞行器 气动力 非定常运动 无穷远条件 数值计算 

分 类 号：V212.11[航空宇航科学与技术—航空宇航推进理论与工程] TV131.4[水利工程—水力学及河流动力学]