Transitional flows with the entropic lattice Boltzmann method

Abstract

The accuracy and performance of entropic multi-relaxation time lattice Boltzmann models are assessed for transitional flows of engineering interest. A simulation of the flow over a low-Reynolds-number $SD7003$ airfoil at $Re=6\times 10^{4}$ , at an angle of attack $\unicode[STIX]{x1D6FC}=4^{\circ }$ , is performed and thoroughly compared to available numerical and experimental data. In order to include blockage and curvature effects, simulations of the flow in a low-pressure turbine passage composed of $T106$ blade profiles, at a chord Reynolds number of $Re=6\times 10^{4}$ or $Re=1.48\times 10^{5}$ , for different free-stream turbulence intensities are presented. Using a multi-domain grid refinement strategy in combination with Grad’s boundary conditions yields good agreement for all simulations. The results demonstrate that the entropic lattice Boltzmann model is a viable, parameter-free alternative to modelling approaches such as large-eddy simulations with similar resolution requirements.