Abstract
The numerical estimation was performed on the heat transfer and flow characteristics of a laminar annular impinging jet with confined insulated wall. Numerical values were obtained for the diameter ratio d/D=0~0.9, the dimensionless distance between nozzle and impingement surface h/ro=0.25~1.0, the Reynolds number Re=100~2000 at Prandtl number Pr=0.72and Grashof number Gr=3×103. The flow was divided into major flow and minor flow. Two kinds of recirculating flows on the upper insulated wall and impingement surface affected the local heat transfer on the impingement surface. Positions of maximum and minimum Nusselt number depend on diameter ratio and Reynolds number, respectively. In addition, the diameter ratio, which mean Nusselt number becomes minimum, exists.