Roughness-Resolved LES of Additive Manufacturing-Like Channel Flows

Abstract In the last decade, progresses in additive manufacturing (AM) have paved the way for optimized heat exchangers whose disruptive design will heavily rely on predictive numerical simulations. However, due to typical roughness induced by AM, current wall models used in steady and unsteady 3D Navier-Stokes simulations do not take into account such characteristics. For the development and assessment of novel wall models for AM, a high-fidelity roughness-resolved Large-Eddy Simulation (RRLES) database is built. This article describes the numerical setup and the methodology used for conducting RRLES, from surface generation to post-processing. In addition, three different cases representing two printing directions plus a streamwise and spanwise isotropic case are investigated. While the roughness distributions are the same in the three cases, the effective slope (ES) is very different and the impact of this parameter on turbulence and heat transfer is analyzed at different Reynolds numbers.