| Title |
Turbulent Heat Transfer of an Oblique Impinging Jet on a Concave Surface |
| Authors |
임경빈 ; 최형철 ; 이세균 ; 최상경 ; 김학주 |
| Keywords |
Oblique impinging jet ; 경사충돌제트 ; Liquid crystal ; 액정 ; Concave surface ; 오목표면 ; Turbulent heat transfer ; 난류열 |
| Abstract |
The turbulent heat transfer from a round oblique impinging jet on a concave surface were experimentally investigated. The transient measurement method using liquid crystal was used in this study. In this measurement, a preheated wall was suddenly exposed to an impinging jet while recording the response of liquid crystals to measure surface temperature. The Reynolds numbers were 11000, 23000 and 50000, nozzle-to-surface distance ratio was from 2 to 10 and the surface angles were α＝0°, 15°, 30° and 40°. Correlations of the stagnation point Nusselt numbers with Reynolds number, jet-to-surface distance ratio and dimensionless surface angle, which account for the surface inclined angle, are presented. The maximum Nusselt numbers, in this experiment, occurred in the direction of upstream. The displacement of the maximum Nusselt number from the stagnation point increases with increasing surface angle or decreasing nozzle-to-surface distance. In this experiment, the maximum displacement is about 0.7 times of the jet nozzle diameter when surface curvature, D/d is 10. |