Numerical Study of Swirling Impinging Jets With Heat Transfer

This paper deals with numerical simulations of circular impinging jets with heat transfer, by means of Large Eddy Simulation (LES). The LES code uses higher order finite-differences on staggered Cartesian non-uniform grids. The current LES have the potential of dealing with transition as well as providing data on details of larger scale structures, statistical correlations and turbulent spectral content. The impinging circular jet has a nozzle-to-plate spacing ranging from 0.5 to 2 nozzle diameters and the Reynolds number is 20000. Three different swirl numbers have been considered, ranging from non-swirling to strongly swirling flow. From the LES results the transition process in the jet is clearly detected. Swirling flow strongly influences the development of the jet. The wall heat transfer rates become obstructed, even though the turbulence level increases.