와이어 스크린 리브이 열전달과 마찰계수에 미치는 효과
Effects of the Wire-screen Rib on Heat Transfer and Friction Factors
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유체 유동에 수직인 방향으로 반복적 리브이 설치된 사각 채널에서 열전달 계수와 마찰계수를 측정하기 위해 실험을 수행하였다. 시험부의 치수는 198 mm(폭)과 40 mm(높이) 그리고 길이가 712mm인 직사각형 채널이다. 시험부 채널의 형상비는 4.95이고 수력 직경 D_h은 6.66 cm이었다. 4종류의 와이어 스크린 리브(rib)과 한 개의 일체형 리브을 사용하였다. 0.1 mm 두께의 스테인레스 강판 히터와 T형 열전대를 사용하였다. 레이놀즈 수의 범위는 20,000에서 60,000이었다. 수력직경( D_h)과 리브의 높(e)이 비(e/ D_h)는 0.075이고 리브 간격(p) 대 높이(e)으 비(p/e)는 10이다. 연구결과 일체형리브이 누셀트수와 마찰계수 모두 가장 컸다.
Abstract
Experiments to determine heat transfer coefficients and friction factors are conducted on a stationary transverse parallel wire-screen rib roughened rectangular channel. The test section consists of 198 mm (W) x 40 mm (H) x 712 mm (L). The channel has the aspect ratio of 4.95 and hydraulic diameter of D_h=6.66 cm. Four wire screen ribs and a solid rib are used. 0.1 mm-thick-stainless steel foil heaters and thermocouples (T type) are used to measure the heat transfer coefficients. Reynolds numbers studied range from 20,000 to 60,000. The wire-screen rib height (e) to hydraulic diameter ( D_h) ratio (e/ D_h) is 0.075; spacing (p) to height ratio (p/e) is 10. Results indicate that the solid rib produces the greatest Nusselt number and friction factor.
참고문헌 (17)
- U. Bin-Nun, "Low cost and high performance screen laminate regenerator matrix", Cryogenics, 44, pp.439~444 (2004)
- A. Kolb, "Experimental studies on a solar collector with metal matrix absorber", Solar Energy, 65, pp.91~98 (1999)
- N. S. Tharur, "Heat transfer and friction factor correlations for packed bed solar air heater for a low porosity system", Solar Energy, pp.319~329 (2003)
- P. J. Richards, "Wind loads on porous structure", J. Wind Eng. Ind. Aerodyn, 83, pp.455~465 (1999)
- A. Bejan, "Cooling of stacks of plates shielded by porous screens", Int. J. Heat Fluid Flow, 16, pp.16~24 (1994)
- J. Tian, "The effects of topology upon fluid-flow and heat transfer within cellular copper structures", Int. J. Heat Mass Transfer, 47, pp.3171~3186 (2004)
- D. W. Zhou, "Heat transfer enhancement of impinging jets using mesh screens", INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 47(10-11), pp.2097~2108 (2004), PERGAMON-ELSEVIER SCIENCE LTD
- S.Ergun, "Fluid flow through packed column", Chem. Eng. Prog, 48, pp.89~94 (1952)
- J. C. Armour, "Fluid flow through woven screens", AIChE J, 14, pp.415~421 (1968)
- J. R. Sodre, "Friction factor determination for flow through finite wire mesh woven screen matrices", ASME J. Fluid Eng, 119, pp.847~851 (1997)
- C. T. Hsu, "Effective stagnant thermal conductivity of wire screen", J. Thermophysics, 10, pp.542~545 (1996)
- M. Ozdemir, "Porosity variation and determination of REV in porous medium of screen meshes", Int. Commun. Heat Mass Transfer, 24, pp.955~964 (1997)
- T.Ebisu, "Development of new concept air-cooled heat exchanger for energy conservation of air-conditioning machine in Heat Transfer Enhancement of Heat Exchangers", pp.601~620 (1999), Kluwer Academic
- W. M. Kays, "Compact heat exchanger" (1964), McGraw Hill
- F. W. Dittus, , University of California(Berkeley) Pub. Eng, 2, pp.443~ (1930)
- E.M.Micheal,Radiative heat transfer,Academic Press, "San Diego", pp.162~189 (2003), Academic Press
- S. J. Kline, "Describing uncertainties in single sample experiments", Mechanical Engineering, 75, pp.3~8 (1953)