ISSN オンライン: 2688-7231
ISBN 印刷: 978-1-56700-497-7 (Flash Drive)
ISBN オンライン: 978-1-56700-496-0
Proceedings of the 25th National and 3rd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2019)
A COMPARISON OF RANS AND LES MODELS FOR THE PREDICTION OF HEAT TRANSFER CHARACTERISTICS OF WALL-JETS.
Researchers have extensively studied the flow characteristics
of a turbulent wall-jet as it exhibits both the turbulent boundary layer and a free shear layer which makes its interaction fascinating. However, the essential application of a wall-jet is in the film cooling of gas turbine blades and combustion chamber liners. With the advent of new manufacturing techniques, intricate shapes in gas turbines are possible to optimize heat transfer. Simulations are required to optimize the design, and thus, the performance of turbulence models in capturing thermal properties needs to be evaluated. In the present study, Reynolds averaged Navier-Stokes model (RANS) with Launder-Sharma K-ε model is tested and compared against a large eddy simulation (LES), Smagorinsky model. Assessment is done to determine their accuracy in the prediction of heat transfer parameters like mean, second-order statistics, and Nusselt number in a wall-bounded turbulent jet at a Reynolds number of 7500. It is observed that even though the low Reynolds number RANS model captures the heat transfer qualitatively, it fails to capture the absolute magnitudes of the mean and fluctuating quantities while, LES results were close to that of the direct numerical simulation (DNS) data.