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- 2016
变加热功率下不同形状微肋阵热沉内的对流换热
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Abstract:
摘要： 为探索变加热功率下微肋阵热沉内的对流换热规律,采用精密机械加工获得圆形、菱形和三角形微肋阵热沉,建立一体式加热试验系统,测试了微肋阵热沉的压力降、流动阻力系数、热阻等对流换热参数,研究Re为0~1 000时微肋阵内阻力及对流换热受加热功率的影响规律。研究结果表明,微肋阵内阻力系数先随加热功率增加而增大,圆形和菱形截面微肋阵中该现象在Re>400时消失,而三角形微肋阵在Re>250时消失。加热功率的增加强化了圆形和菱形截面微肋阵内的对流换热,三角形微肋阵的Nu在Re<250时随加热功率的增加而增大,当Re>250后则有所降低;加热功率对于圆形和菱形微肋阵热沉热阻的影响在Re<600时较为明显,而对于三角形微肋阵当Re>250后加热功率对于热阻的影响基本可以忽略。
Abstract: In order to investigate the flow and convective heat transfer characteristics under different heating loads in micro pin fins,test sections of micro pin fins with different cross section shapes of circle, diamond and triangle were precision machined. An integraed heating system was used to to measure the pressure drops, frictional resistance factors and thermal resistance in micro pin fins. Based on the experimental results, the impact of heating load on the flow resistance and the heat transfer in micro pin fins with Reynolds number ranging from 0~1 000 was explored. It was found that the friction factors in the three types of micro pin fins became large with the increase of the heating load, but this phenomenon disappeared when Re>400 for the circle and diamond micro pin fins, and Re>250 for the triangular micro pin fins. The convective heat transfer in micro pin fins with cross section shapes of circle, diamond was enhanced by increasing the heating load, but the Nu in triangular micro pin fins became large with the increase of the heating load when Re<250, and then it became slightly smaller when Re>250
| [1] | PELES Y, KO??塁AR A, MISHRA C, et al. Forced convective heat transfer across a pin fin micro heat sink[J]. International Journal of Heat and Mass Transfer, 2005, 48(17):3615-3627. |
| [2] | KO??塁AR A, MISHRA C, PELES Y. Laminar flow across a bank of low aspect ratio micro pin fins[J]. Journal of Fluids Engineering, 2005, 127(3):419-430. |
| [3] | CHANG S W Y W HU. Endwall thermal of performances of radially rotating rectangular channel with pin-fins on skewed rib lands [J]. International Journal of Heat and Mass Transfer, 2014, 69:173-190. |
| [4] | 张承武,浦龙梅,姜桂林等.不同截面形状微肋片内流动阻力特性[J].化工学报,2014,65(6):2042-2048. ZHANG Chengwu, PU Longmei, JIANG Guilin, et al. Resistance characteristics of micro pin fins with different cross-section shapes[J]. CIESC Journal, 2014, 65(6):2042-2048. |
| [5] | TULLIUS J F, TULLIUS T K, Bayazitoglu Y. Optimization of short micro pin fins in minichannels[J]. International Journal of Heat and Mass Transfer, 2012, 55(15-16):3921-3932. |
| [6] | 刘志刚,张承武,管宁.叉排微柱群内顶部间隙对传热效率的影响[J].化工学报,2012,63(4):1025-1031. LIU Zhigang, ZHANG Chengwu, GUAN Ning. Influence of tip clearance on heat transfer efficiency in staggered micro-cylinders-group[J]. CIESC Journal, 2012, 63(4):1025-1031. |
| [7] | MOFFAT R J. Describing the uncertainties in experimental results [J]. Experimental Thermal and Fluid Science, 1988, 1(1):3-17. |
| [8] | HAMID R S, MORTEZA F. Computational analysis of nanofluid effects on convective heat transfer enhancement of micro-pin-fin heat sinks[J]. International Journal of Thermal Science, 2012, 58:168-179. |
| [9] | MEI D Q, LOU XY, QIAN M, et al. Effect of tip clearance on the heat transfer and pressure drop performance in the micro-reactor with micro-pin-fin arrays at low Reynolds number[J]. International Journal of Heat and Mass Transfer, 2014, 70:709-718. |
| [10] | SHAHABEDDIN K M, YUWEN Z. Analysis of nanofluid effects on thermoelectric cooling by micro-pin-fin heat exchangers[J]. Applied Thermal Engineering, 2014, 70(1):282-290. |
| [11] | MUSHTAQ I H. Investigation of flow and heat transfer characteristics in micro pin fin heat sink with nano fluid[J]. Applied Thermal Engineering, 2014, 63(2):598-607. |
| [12] | ADEWUMI O O, BELLO-OCHENDE T, MEYER J P. Constructal design of combined microchannel and micro pin fins for electronic cooling[J]. International Journal of Heat and Mass Transfer, 2013, 66:315-323. |
| [13] | MOORES K A, KIM J, JOSHI Y. Effect of tip clearance on the thermal and hydrodynamic performance of shrouded pin fin arrays[D]. Maryland: Department of Mechanical Engineering, University of Maryland, 2008. |
| [14] | MOHAMMAD M M, KOK-CHEONG W, MANSOOR S. Numerical investigation of fluid flow and heat transfer under high heat flux using rectangular micro-channels[J]. International Journal of Commumications in Heat and Mass Transfer, 2012, 39(2): 291-297. |
| [15] | ABAS A, JIMENEZ G, DULIKRAVICH G S. Thermo-fluid analysis of micro pin fin array cooling cofigurations for high heat fluxes with a hot spot[J]. International Journal of Thermal Science, 2015, 90:290-297. |
| [16] | REYES M, ARIAS J R, VELAZQUEZ A, et al. Experimental study of heat transfer and pressure drop in micro-channel based heat sinks with tip clearance[J]. Applied Thermal Engineering, 2011, 31(5):887-893. |
| [17] | KO??塁AR A, PELES Y. Thermal-hydraulic performance of MEMES-based pin fin heat sink[J]. Journal of Heat Transfer, 2006, 128(2):121-131. |
| [18] | MUSTAFA K, MEHMED R O, KO??塁AR A. Parametric study on the effect of end walls on heat transfer and fluidflow across a micro pin-fin[J]. International Journal of Thermal Science, 2011, 50(6):1073-1084. |
| [19] | 张承武,刘志刚,管宁.加热热通量对微柱群通道内强迫对流换热的影响[J].化工学报,2010,61(12):3080-3085. ZHANG Chengwu, LIU Zhiang, GUAN Ning. Influence of heat flux on forced convective heat transfer in duct with micro-cylinder-group [J]. CIESC Journal, 2010, 61(12):3080-3085. |
| [20] | MOORES K A, KIM J, JOSHI Y K. Heat transfer and fluid flow in shrouded pin fin arrays with and without tip clearance[J]. International Journal of Heat and Mass Transfer, 2009, 52(25-26):5978-5989. |
| [21] | REINHARD R, GABRIEL L, KEITH C, et al. Heat transfer in freestanding microchannels with in-line and staggered pin fin structures with clearance[J]. International Journal of Heat and Mass Transfer, 2013, 67:1-15. |
