The camera method, or how to track numerically a deformable particle moving in a fluid network

TL;DR

This paper introduces the camera method, a finite element-based approach that efficiently tracks deformable particles in fluid flows by focusing on a moving neighborhood around the particle, reducing computational complexity and mesh distortion.

Contribution

The paper presents the camera method, a novel finite element technique that localizes fluid-structure interaction to a moving neighborhood, improving simulation of particles in fluid networks.

Findings

Effective in 2D axi-symmetry, 2D, and 3D cases

Reduces degrees of freedom and mesh distortion

Applicable to various fluid-structure interaction problems

Abstract

The goal of this work is to follow the displacement and possible deformation of a free particle in a fluid flow in 2D axi-symmetry, 2D or 3D using the classical finite elements method without the usual drawbacks finite elements bring for fluid-structure interaction, i.e. huge numerical problems and strong mesh distortions. Working with finite elements is a choice motivated by the fact that finite elements are well known by a large majority of researchers and are easy to manipulate. The method we describe in this paper, called the camera method, is well adapted to the study of a single particle in a network and most particularly when the study focuses on the particle behaviour. The camera method is based on two principles: 1/ the fluid structure interaction problem is restricted to a neighbourhood of the particle, thus reducing drastically the number of degrees of freedom of the problem; 2/ the neighbourhood mesh moves and rotates with the particle, thus avoiding most of the mesh distortions that occur in a standard ALE method. In this article, we present the camera method and the conditions under which it can be used. Then we apply it to several examples from the literature in 2D axi-symmetry, 2D and 3D.