Abstract
Two available low-Reynolds-number k-σ turbulence models have been used to predict turbulent natural convection within a differentially heated enclosure for the purpose of assessing their relative merits. In one model, fixed numerical values are employed for the model coefficients; in the other model, the coefficients vary with the value of the local turbulence Reynolds number. The numerical results from both models are compared to published experimental data. In general, the variable coefficient model predicts lower turbulence levels than the fixed coefficient model. Both models predict measured velocity profiles adequately, but overall, the predictions of the variable coefficient model are superior. The average Nusselt numbers are predicted more accurately by the variable coefficient model than by the fixed coefficient model.
Notes
Address correspondence to S. Ramadhyani, Heat Transfer Laboratory, School of Mechanical Engineering, Purdue University, 1288 Mechanical Engineering Building, West Lafayette, IN 47907-1288, USA.