Direct Numerical Simulation of turbulent mixed convection in a vertical channel for the assessment of relaminarization effects on the hot wall

Abstract

Buoyancy driven flows play a major role in engineering applications, making it crucial to be able to develop appropriate tools for their simulation. A detailed computation of all scales in flows with industrial relevance, as it is possible with a Direct Numerical Simulation (DNS), requires enormous resources, speaking temporally and computationally. The Large Eddy Simulation (LES) technique has been established as means of reducing the amount of computational resources needed while providing information about the large vortices in a flow by spatial filtering and modeling of the small scales. The LES needs a model of the unresolved scales in the flow in order to yield physically correct results, which needs to be validated against the results of a DNS capturing all essential flow scales. In order to create the data to evaluate different subgrid scale (SGS) models needed for an LES, results of a DNS of turbulent flow with mixed convection through a vertical channel with differentially heated walls is presented here.