| Title |
Effect of Surface Roughness on Two-Phase Flow Heat Transfer by Confined Liquid Impinging Jet |
| Keywords |
Confined jet ; 구속제트 ; Surface roughness ; 표면거칠기 ; Free surface ; 자유표면 ; Submerged jet ; 잠입제트 ; Jet impingement ; 충돌제트 |
| Abstract |
The water jet impingement cooling with boiling is one of the techniques to remove heat from high heat flux equipments. The configuration of surface roughness is one obvious condition of affecting the performance on heat transfer in nucleate boiling. The present study investigates the water jet impinging single-phase convection and nucleate boiling heat transfer for the effect of surface roughness to enhance the heat transfer in free surface and submerged jet. The distributions of the averaged wall temperature as well as the boiling curves are discussed. Jet velocities are varied from 0.65 to 1.7m/s. Surface roughness by sand blast and sand paper varies from 0.3 to 2.51m and cavity shapes on surface are semi- circle and v-shape, respectively. The results showed that higher velocity of the jet caused the boiling incipience to be delayed more. The incipient boiling and heat transfer increase with increasing surface roughness due to a large number of cavities of uniform size. |