GAS JET IMPINGEMENT ON A SURFACE HAVING A LIMITED CONSTANT HEAT FLUX AREA: VARIOUS TURBULENCE MODELS

Abstract

The orthogonal jet impingement method is used in the processing industry to achieve intense heating, cooling, or drying rates. The present study examines jet impingement on a surface having a constant heat flux over a limited area. Air is considered as the impinging gas, and the process is simulated with a two-dimensional axisymmetric form of the governing conservation equations. Four turbulence models, including standard k-epsilon, low Reynolds number k-epsilon, and two Reynolds stress models, are introduced to account for the turbulence. A numerical scheme employing the control volume approach is introduced when discretizing the governing equations. To validate the theoretical results, the flow properties predicted from the present study are compared with the previously reported experimental findings. It is found that the standard k-epsilon model predicts excessive kinetic energy generation in the vicinity of the stagnation region, which in turn, results in excessive heat transfer and lowering of the temperature in this region. On the other hand, the agreement between the temperature profiles predicted from both the low Reynolds number k-epsilon model and the Reynolds stress turbulence model are better than that obtained from the standard k-epsilon model.