A Numerical Study of Heat Transfer on a Fin in Force and Natural Convection

• Main Authors: Chun-Feng Huang, 黃群峰
• Other Authors: Shun-Ching Lee
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/86283829320328523169

碩士 === 國立高雄應用科技大學 === 機械與精密工程研究所 === 95 === Using heat sinks to increase the area of cooling is the most common yet the most basic of heat management techniques. As heat generation density in electronic elements increases, demand for cooling rises. The more difficult the cooling design, the higher the cost. To meet the demand for cooling in electronics, therefore, shape, material and process of heat sinks all require newer techniques. In this study, COSMOS FloWorks is used to simulate the efficiency of heat transfer in oblique heat fins in natural convection and forced convection. The main purpose is to analyze: (1) the heat transfer of fins (plate, pin and sheet type) at different Reynolds numbers, slopes and arrangements (staggered and in-line) in forced convection; (2) the cooling efficiency of different fin thicknesses and spaces between fins at slope 1.9 in forced convection; (3) the effect of heat transfer characteristics of plate type, pin type and sheet type at different slopes and different Rayleigh number in natural convection. Experiment data from G.Ledezma and A.Bejan [1] (1995) was used to verify the results. It was found that, at Reynolds number 3750 with forced convection and slope of the radiator 0, data from the reference [1] and this experiment are somewhat different, yet the trend of simulation values is the same as the reference. Moreover, in the reference, at Reynolds number 3750 with forced convection, there may be some problems in experiment data. At fin slope b=0, in-line pin and sheet radiators and staggered pin and sheet radiators outperformed ordinary plate radiators. Grooves on the sides of the fins gave rise to an increase in thermal convection performance and thereby achieved a cooling effect. Grooves on the sides of fins of other slopes increased their performance as the Reynolds number rose. As well, the cooling effect of in-line fins was better than that of staggered fins.