| Title |
Change of Heat Transfer Characteristics in a Rotating Channel of Square Duct at Wall with Bleed Holes(Ⅱ) －Effects of Exit Mass Flow Rate |
| Authors |
김상인 ; 김경민 ; 이동현 ; 전윤흥 ; 조형희 |
| Keywords |
Bleed hole ; 유출홀 ; Coriolis force ; 코리올리력 ; Naphthalene sublimation technique ; 나프탈렌승화법 ; Rotating duct ; 회전덕트 |
| Abstract |
The present study has been conducted to investigate convective heat/mass transfer in the cooling passage with bleed holes. The rotating square channel has 40.0mm hydraulic diameter and the bleed holes on the leading surface of the channel. The hole dia-meter of bleed hole is 4.5mm and its spacing is (4.9) about five times of hole dia-meter. Exit mass flow rate through bleed holes is 0%, 10% and 20% of the main mass flow rate respectively. rotation number is fixed 0.2. A naphthalene sublimation technique is employed to determine the detailed local heat transfer coefficients using the heat and mass transfer analogy. The cooling performance is influenced by exit mass flow rate through bleed holes and Coriolis force of rotating channel for fixed Reynolds number. The heat transfer on the leading surface is decreased due to Coriolis force. However the total heat transfer is enhanced around holes on the leading surface because of trapping flow by bleeding. |