基于流固耦合的直接虚拟区域法离散δ函数研究

研究直接虚拟区域法中欧拉点和拉格朗日点上速度、虚拟力等物理量的交换函数在流固耦合计算中的应用.通过直接虚拟区域法中运用不同类型和收敛阶的离散δ函数,对颗粒在液体中自由沉降的流固耦合问题进行分析,得出了选择直接虚拟区域法中离散δ函数的原则.根据欧拉网格特点选择δ_h(r)函数和拉格朗日网格特点选择δ_h(r)函数,率先提出了δ_h(r)≠δ_h(r)的新构造方法,使直接虚拟区域法能更加精确和高效地模拟出颗粒在流体中自由沉降这一重要问题,并通过了数值试验论证.

The Discrete Delta Function Study of Direct Fictitious Domain Method Based on Fluid-Structure Interaction

The exchange functions of physical quantities such as velocity,virtual force at the Euler point and Lagrange point are applied to the fluid-structure interaction in direct fictitious domain method in this paper.By using different types and convergence order of the discrete δ functions,fluid-structure interaction problems of sedimentation of a circular particle in liquid are analyzed,and the new method of the discrete δ function is obtained.According to the Euler characteristics of grids select δ_h(r) function and Lagrange grids select δ_h(r) function,a new construction method of δ_h(r)≠δ_h(r) is proposed,which makes the direct fictitious domain method more accurate and more efficient simulation of particle's sedimentation in liquid,and through the numerical experiments demonstrate.