A posteriori analysis of non-dissipative large-eddy simulation of wall-bounded transcritical turbulent flow

Abstract

A posteriori analyses based upon a recently proposed non-dissipative large-eddy simulation framework for high-pressure transcritical wall-bounded turbulence have been carried out. Due to the numerical complexities that arise in such type of flows, the discretization requires kinetic-energy- and pressure-equilibrium-preservation schemes to yield stable and non-dissipative scale-resolving simulations. On the basis of this framework, the objectives are to: (i) compute wall-resolved large-eddy simulations of a high-pressure transcritical turbulent channel flow, and (ii) assess the thermofluid performance with respect to a direct numerical simulation at a low-Reynolds-number regime. In this regard, three different subgrid-scale stress tensor models have been considered, together with models for the unresolved scales of the filtered pressure transport and state equations. The study shows that the results of the subgrid-scale stress tensors examined slightly deviate, under these extreme conditions, from the time-averaged velocity and temperature reference solutions. Differently, in terms of bulk performance, it has been found that the skin-friction coefficient and Nusselt number are relatively well captured at the cold and hot walls. Thus, it is concluded that dedicated efforts by the research community are needed to improve the prediction accuracy of existing subgrid-scale models for wall-bounded transcritical turbulence.