ASSESSMENT OF A ONE-EQUATION TURBULENCE MODEL FOR STRONGLY HEATED GAS FLOWING UPWARD IN A VERTICAL TUBE

摘要

A one-equation near-wall turbulence model is used to predict a strongly heated, low-Mach-number gas flowing upward in a vertical tube. Intense wall heating causes significant and continuous fluid property variation and thickening of the viscous sub-layer. Consequently, a fully developed flow does not evolve. Existing literature reveals that two-equation models with various near-wall approaches generally perform poorly under such conditions. However, the one-equation model considered in this study is shown to accurately predict this flow through adjustment of a model constant related to the viscous sub-layer thickness.