単一円形衝突噴流熱伝達に及ぼすグラスホフ数およびプラントル数の影響 Effects of Grashof Number and Prandtl Number on Heat Transfer of a Single Circular Impinging Jet with Confined Wall
The numerical estimation was performed on the effects of Grashof number and Prandtl number in a single circular impinging jet with confined insulated wall. Numerical values were obtained for the Reynolds number Re = 100 and 500, the Prandtl number Pr = 0.01 ∼ 1,000, the Grashof number Gr = O∼10,000 and the dimensionless distance between nozzle and impingement surface H=1.0. In the case of a normal jet, a recirculated flow was generated on the insulated upper wall and the local heat transfer was improved with increase of Grashof numbers because of a flow accerelation near the impingement surface. However, in the case of a jet inverse to gravity direction, the local heat transfer was depressed because a recirculated flow region by the buoyancy was generated on the impingement surface. Effects of Prandtl number were also examined. The characteristics of average Nusselt numbers along various Prandtl numbers were divided into three regions.
日本冷凍空調学会論文集 14(2), 169-177, 1997-07-31