| Title |
The Study on the Phenomenon of Heat Transfer on a Downward Isothermal Circular Surface by an Impinging of Upward Circular Nozzle Jet |
| Authors |
In Jae Lee ; Yong Kyoon Eom |
| DOI |
http://dx.doi.org/10.6110/KJACR.2016.28.11.450 |
| Keywords |
충돌 제트 열전달 ; 하향 등온 원형평판 ; 상향원형제트 Impinging jet heat transfer ; Downward isothermal circular plate ; Upward round jet |
| Abstract |
While many studies on the heat transfer effect of an impinging jet have been published, most studies focus on the downward impinging jet. This study investigates the impinging jet heat transfer phenomenon when water at a temperature of 24℃ impinges on the downward isothermal circular plate at 60, 70, and 80℃ and when the upward round jet nozzle is 4, 6, and 8 mm diameter with a flow rate 3.6, 4.6, and 5.6 L/min, respectively, and when the ratio of the nozzle clearance/nozzle diameter (H/D) is 1. The results showed that, as the nozzle diameter decreases, the heat transfer coefficient increases at a constant flow rate. The correlation equation of Nur, Prr, and Rejg is obtained in the impinging and constant velocity flow region (Nur/Prr0.4) Dr=4.6[Rejg(r/Rc)Dr]0.8 at all flow rates, in the deceleration and falling flow regions (Nur/Prr0.4) Dr=42.7|Rejg(r/Rc)Dr-345.7|0.3 at 3.6 L/min, (Nur/Prr0.4) Dr=92.4|Rejg(r/Rc)Dr-16.8|0.2 at 4.6 L/min, (Nur/Prr0.4) Dr=322.4|Rejg(r/Rc)Dr-536.2|0.01 and at 5.6 L/min. |