Experimental and LBM analysis of medium-Reynolds number fluid flow around NACA0012 airfoil

TL;DR

This study validates Lattice Boltzmann Method (LBM) coupled with LES turbulence modeling against wind tunnel experiments for flow around a NACA0012 airfoil at medium Reynolds number, demonstrating high accuracy and computational efficiency.

Contribution

It introduces a high-resolution LBM-LES approach for accurate CFD analysis of airfoil flow, validated against experimental data at Re=191000.

Findings

LBM-LES provides highly accurate predictions of pressure coefficients.

Max RMSE of 0.105 on upper surface and 0.089 on lower surface.

Method enables efficient CFD analysis on high-performance computing architectures.

Abstract

Cornerstone of this research is the examination of fluid flow around NACA0012 airfoil, with the aim of the numerical validation between the experimental results in the wind tunnel and the Lattice Boltzmann Method (LBM) analysis, for the medium Reynolds number (Re = 191000). The LBM-Large Eddy Simulation (LES) method described in this paper opens up opportunities for faster computational fluid dynamics (CFD) analysis, because of the LBM scalability on high performance computing architectures, more specifically general purpose graphics processing units (GPGPUs), pertaining at the same time the high resolution LES approach. Process starts with data collection in open-circuit wind tunnel experiment. Furthermore, the pressure coefficient, as a comparative variable, has been used with varying angle of attack (2, 4, 6 and 8 degrees) for both experiment and LBM analysis. To numerically reproduce the experimental results, the LBM coupled with the LES turbulence model, the generalized wall function (GWF) and the cumulant collision operator with D3Q27 velocity set has been employed. Also, a mesh independence study has been provided to ensure result congruence. The proposed LBM methodology is capable of highly accurate predictions when compared to experimental data. Besides, the special significance of this work is the possibility of experimental and CFD comparison for the same domain dimensions. Considering the quality of results, Root-Mean-Square Error (RMSE) shows good correlations both for airfoil's upper and lower surface. More precisely, maximal RMSE for the upper surface is 0.105, while 0.089 for the lower surface, regarding all angles of attack.