A moving least square immersed boundary method for SPH with thin-walled structures

TL;DR

This paper introduces a moving least squares immersed boundary method for SPH that enhances accuracy and stability in simulating thin-walled structures without multiple boundary layers.

Contribution

It develops a novel LSIB method that simplifies thin-walled structure simulations and improves 3D accuracy and stability compared to existing methods.

Findings

Achieves smooth velocity and pressure fields in impulsively started plate simulations.

Accurately predicts forces and vortex wake development in flow past cylinder.

Remains stable and interference-free in three-dimensional simulations.

Abstract

This paper presents a novel method for smoothed particle hydrodynamics (SPH) with thin-walled structures. Inspired by the direct forcing immersed boundary method, this method employs a moving least square method to guarantee the smoothness of velocity near the structure surface. It simplifies thin-walled structure simulations by eliminating the need for multiple layers of boundary particles, and improves computational accuracy and stability in three-dimensional scenarios. Supportive three-dimensional numerical results are provided, including the impulsively started plate and the flow past a cylinder. Results of the impulsively started test demonstrate that the proposed method obtains smooth velocity and pressure in the, as well as a good match to the references results of the vortex wake development. In addition, results of the flow past cylinder test show that the proposed method avoids mutual interference on both side of the boundary, remains stable for three-dimensional simulations while accurately calculating the forces acting on structure.