About fluid forces computation for Volume Penalization coupled with Lattice Boltzmann method (VP-LBM)

TL;DR

This paper compares two methods for computing fluid forces in the VP-LBM framework, analyzing their differences through simulations of airfoil lift/drag and particle sedimentation.

Contribution

It introduces a comparative analysis of momentum exchange and stress integration methods within VP-LBM for fluid force computation.

Findings

Significant differences observed between the two methods in force calculations.

The methods yield different lift and drag coefficients for the airfoil.

Results highlight the importance of method choice in VP-LBM simulations.

Abstract

In this paper, two different approaches fluid forces computation approaches are compared in the frame of Volume Penalization - Lattice Boltzmann Method (VP-LBM). The first method, the momentum exchange method, uses the variation of the distribution functions near the fluid solid interface, while the second one, the stress integration method, allows direct integration of fluid forces onto this interface. Applied to the VP-LBM, which consists in penalizing the solid in the LBM, these two methods lead to significantly different results. The tests are performed to study on one hand the lift and drag coefficients of a Naca 0012 airfoil at different angles of attack, at Reynolds number 1000, and on the other hand, the particle sedimentation under gravity in a channel.