Application of the lattice Boltzmann method combined with large-eddy simulations to turbulent convective heat transfer

In this paper, the large-eddy simulation is introduced into the lattice Boltzmann method to study convective heat transfer in turbulent flows. The simulations include a closed lid-driven cavity flow and a backward-facing step flow in both laminar and turbulent regions. The results show that by combining with large-eddy simulations, the lattice Boltzmann method can simulate turbulent flow phenomena well and give good agreement with other experimental and numerical results, while the traditional lattice Boltzmann method fails. Quaternary vortices of the turbulent cavity flows are captured in the simulations as well as the transient vortices of backward-facing step flows. By calculating the distribution of skin-friction coefficients and Nusselt number on the lower wall, the drag and heat transfer efficiency of backward-facing step flows are found to be influenced by the vortices generated near walls significantly, no matter the flow is laminar or turbulent. For laminar cases, the flow phenomena are also greatly affected by the Reynolds number. But in turbulence, the flow field is fully perturbed and chaotic, so that the transport phenomena are approximately independent of the Reynolds number.