潜体非定常兴波问题的数值求解

摘要

开发了一种求解非定常兴波问题的基于非均匀有理B样条(NURBS)的三维面元法,应用该方法对潜体加速航行的情况进行了数值计算研究.基于势流理论,建立了线性边值问题,在物面上分布时域Kelvin源,物面和物面上的源强分布都用NURBS来表示.用时间步进的方法求解这一边值问题.对潜体中低速航行的情况进行了计算,给出了即时的波阻和波型.%A 3D high-order panel method based on Non-Uniform Rational B Spline (NURBS) has been developed to solve the unsteady wave-making problem caused by a submerged body in accelerated motion. Based on the potential flow theory, a linear boundary value problem is formulated in time domain. The velocity potential is expressed by a time-domain Kelvin source distribution on the body surface. The body surface is geometrically described by NURBS, and the singularity distribution on the surface is also expressed by NURBS. The problem is solved in a time-marching manner in time domain. Calculations are conducted for a submerged spheroid beneath the free surface at low or moderate speed. The instant wave resistance and wave elevation are obtained. The results are presented and discussed.