Analysis of heat transfer and flow characteristics in turbulent impinging jet

Abstract

Jet impingement technique is characterized by a high heat removal capability. As such it has been proposed as a cooling method for the helium cooled divertor, a high-heat flux component of the future fusion reactor called DEMO. Since power plant efficiency depends on the divertor’s heat removal capability it has to meet certain demands, i.e. high-heat transfer and low pressure drop. In this paper local heat transfer and flow characteristics of an axis-symmetric impinging jet are analyzed numerically using the RANS approach and eddy viscosity type SST turbulence model. Turbulence models and heat transfer predictions are validated on the free jet impingement experiment ( Baughn and Shimizu, 1989). Since the numerical results are affected by the turbulence model the influence of the turbulent production is investigated in particular. The validated numerical model is further applied to analyze the effect of the nozzle inlet shape on the heat removal capability and pressure drop in the confined impinging jet. Two different nozzle inlet parameters are tested; chamfer angle θ and chamfer depth L c h . The numerical results are compared with the experimental data ( Brignoni and Garimella, 2000).