Direct Numerical Simulation of Stably-Stratified Turbulent Channel Flow with CO2 Supercritical Pressure

摘要

Direct Numerical Simulations of stably-stratified turbulent channel flows were carried out to investigate the effects of strongly property change in supercritical pressured fluids on turbulent structures and heat transfer. Fully-developed stably-stratified turbulent channel flows at CO2 supercritical pressure (7.58 MPa) were targeted. In this condition, Prandtl number changed between 8.8 and 33 and turbulent Richardson number was 14.2. As the results, effects of the property change on the budget of mean energy were remarkably appeared. And flow laminarization was observed due to the buoyancy effect, however, buoyancy effects on turbulent statistics seem to be reduced compared with the same turbulent Richardson condition but low-Pr case.