Transitional flows with the entropic lattice Boltzmann method

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 x 10(4), at an angle of attack alpha = 4 degrees, 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 T10(6) blade profiles, at a chord Reynolds number of Re = 6 x 10(4) or Re = 1 : 48 x 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.