A 3D-CFD methodology to investigate boundary layers and assess the applicability of wall functions in actual industrial problems: A focus on in-cylinder simulations

摘要

In the industrial practice, 3D-CFD in-cylinder simulations still largely rely on RANS turbulence models and highReynolds wall treatments, i.e. based on wall functions. However, the use of the latter represents a potential source of error, leading to poor estimations of shear stress and heat flux at the wall. In fact, universal laws of the wall can be claimed only under very restricted conditions, which are hardly (to say never) met in industrial applications. As a result, typical dimensionless profiles of velocity and temperature on the combustion chamber walls are far from standard wall functions.