Surface curvature effect on slot-air-jet impingement cooling flow and heat transfer process
- National Cheng Kung Univ., Tainan (Taiwan)
Experiments are performed to study surface curvature effects on the impingement cooling low and the heat transfer processes over a concave and a convex surface. A single air jet issuing from different size slots continuously impinges normally on the concave side or the convex side of a heated semicylindrical surface. An electrical resistance wire is used to generate smoke, which allows the authors to visualize the impinging flow structure. The local heat transfer Nusselt number along the surfaces is measured. For impingement on a convex surface, three-dimensional counterrotating vortices on the stagnation point are initiated, which result in the enhancement of the heat transfer process. For impingement on a concave surface, the heat transfer Nusselt number increases with increasing surface curvature, which suggests the initiation of Taylor-Goertler vortices along the surface. In the experiment, the Reynolds number ranges from 6,000 to 350,000, the slot-to-plate spacing from 2 to 16, and the diameter-to-slot-width ratio D/b from 8 to 45.7. Correlations of both the stagnation point and the average Nusselt number over the curved surface, which account for the surface curvature effect, are presented.
- OSTI ID:
- 7206907
- Journal Information:
- Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States), Vol. 113:4; ISSN 0022-1481
- Country of Publication:
- United States
- Language:
- English
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