非线性双渐进法应用于水中结构瞬态运动的研究

Transient motions of submerged structures with nonlinear fluid-structure interaction method

为了解决线性双渐近法只能用于解决准静态条件下的流固耦合问题的局限性,提出了解决流固耦合问题的非线性双渐进法。并将其应用于瞬态载荷作用下具有初始航速结构的流固耦合计算当中。研究了水平初速度系数下流场的动压力时历曲线,分析非线性对结构运动前期、中期、后期周围流场动压力的影响,分析无量纲单位面积冲量随水平初速度系数的变化趋势。给出了非线性效应不能被忽略的初始速度条件,进而研究了非线性双渐近法的适用范围。

For the purpose to overcome big limitation of DAA only being applicable to semi-static fluid-structure interaction problems,nonlinear doubly asymptotic approximation method was proposed.The method was used to compute transient FSI problems of a moving submerged body.The pressure-time curves were analyzed at different horizontal initial velocities,and the effects of nonlinearity on the fluid pressure at earlier,intermediate and later times were studied.The change of nondimensional unit-area impulse was investigated along with the horizontal initial velocity.Finally,the initial velociy condition with unneglectable nonlinear effect was given,further the applicability of the NDAA was studied.