常航速船波势及船波阻力的边界元法

A Boundary Element Method for the Potential Problem of a Ship Moving Forward at Constant Speed

利用满足Laplace方程,线性化自由面条件及无穷远处条件的Havelock兴波源涵数,建立了关于常航速稳态船波势函数的边界积分方程.针对这个积分方程,建立了相应的数值计算方法,编制了一般三维问题的边界元法计算机程序,可用来计算全潜和半潜物体的稳态绕流场及船舶兴波阻力.

Using Havelock source function a boundary element method for the potential problem of a ship moving forward at constant speed is developed. The Havelock source function satisfies the Laplacian equation (except at the source point), the linear free surface condition and the boundary conditions at infinity. But for surface ships, this method is difficult to adopt because of an extra line integral in the governing integral equation. The line integral is applied at the intersection of the free surface and the ship's surface, where the Havelock source function is not well defined. By use of differential geometry theory the line integral is evaluated numerically and appropriate equations are established for the discrete set of nodes on the line integral route, so that the problem can be solved by BEM. A FORTRAN computer program is developed using the above-mentioned method for the evaluation of the flow field and the wave resistance of both a submerged body and a surface ship. The authors' predictions for a submerged sphere and a semi-submerged sphere are compared satisfactorily with other theoretical results.