Scale-resolving simulations using a lattice Boltzmann-based approach

Abstract

This paper summarizes the fundamental concepts behind the lattice Boltzmann approach for scale-resolving numerical flow simulations with a brief description of the solver algorithms and models in the lattice Boltzmann-based code PowerFLOW. The focus is put on representative simulation examples including a direct numerical simulation of a channel and the NACA0012 airfoil at a chord Reynolds number of 657,000 resolving all the turbulent scales and several fundamental cases increasing in flow and geometric complexity demonstrating the hybrid turbulence approach which is resolving only the large coherent turbulent structures, while smaller turbulent flow structures are modeled. Simulation results of a simple shear layer flow, a smooth body separation on the NASA Hump and iced airfoils are documented. The results provide a good overview of the high accuracy achieved for transitioning and separated turbulent flow situations and the mechanisms initiating the switch from mainly modeled to mainly resolved turbulent flow structures. Combined with the high efficiency of the numerical method, developments following the described strategy are expected to evolve further and allow additional industrial deployment.