不同实度扰流柱阵列的流动与换热特性研究
|
摘要
采用剪切压力传输SST k-?湍流模型对3种不同实度扰流柱阵列的换热效果与流动特性进行数值模拟。根据冷却流体的流场结构,分析扰流柱实度对冷却通道内传热性能及压力损失系数的影响规律。结果表明:随着扰流柱阵列实度等级的增加,冷却气体动能降低,其流向速度呈周期性分布,通道内端壁面积缩小,但低温区域所占面积比重明显增大;扰流柱阵列的平均换热水平随进口雷诺数的增大呈指数上升趋势,高实度的扰流柱换热效果更佳,且在流场上下游分别出现换热峰值;冷却通道的整体压力损失系数随进口雷诺数的增大呈指数下降分布,高实度通道下降速率最大,其整体压力损失系数在高雷诺数阶段达到最低,在流向上沿程压力损失系数呈先降后升趋势。
Numerical simulation on heat transfer and flow characteristics of three pin fin arrays with different solidity degrees are carried out by using SST k-ω turbulence model. According to the structure of the cooling gas flow field, the influence of solidity degree on heat transfer and pressure loss coefficient in the cooling channel was analyzed. The result shows that, with the increasing solidity degree of the pin fin arrays, the kinetic energy of the cooling flow reduces, and its own speed exhibits a periodic distribution. The area of the endwall becomes smaller, but the area ratio of the low temperature area with higher heat transfer efficiency increases. The average heat transfer level of the pin fin arrays with different solidity degrees increases exponentially with the inlet Reynolds number, the high solidity array has a higher heat transfer effect, and there are two highest points appear in the upper and lower flow direction. The pressure loss coefficient decreases exponentially in different solidity degrees, the high solidity pin fin arrays decreases faster, and the pressure loss coefficient at high Reynolds number is the lowest, the pressure loss coefficient of the flow decreases firstly and then increases.
Numerical simulation on heat transfer and flow characteristics of three pin fin arrays with different solidity degrees are carried out by using SST k-ω turbulence model. According to the structure of the cooling gas flow field, the influence of solidity degree on heat transfer and pressure loss coefficient in the cooling channel was analyzed. The result shows that, with the increasing solidity degree of the pin fin arrays, the kinetic energy of the cooling flow reduces, and its own speed exhibits a periodic distribution. The area of the endwall becomes smaller, but the area ratio of the low temperature area with higher heat transfer efficiency increases. The average heat transfer level of the pin fin arrays with different solidity degrees increases exponentially with the inlet Reynolds number, the high solidity array has a higher heat transfer effect, and there are two highest points appear in the upper and lower flow direction. The pressure loss coefficient decreases exponentially in different solidity degrees, the high solidity pin fin arrays decreases faster, and the pressure loss coefficient at high Reynolds number is the lowest, the pressure loss coefficient of the flow decreases firstly and then increases.
引文
[1]HAN J C,DUTTA S.燃气轮机传热和冷却技术[M].西安:西安交通大学出版社,2005:1-3.HAN J C,DUTTA S.Gas turbine heat transfer and cooling technology[M].Xi’an:Xi’an Jiaotong University Press,2005(in Chinese).
[2]蒋洪德,任静,李雪英,等.重型燃气轮机现状与发展趋势[J].中国电机工程学报,2014,34(29):5096-5102.JIANG Hongde,REN Jing,LI Xueying,et al.Status and development trend of the heavy duty gas turbine[J].Proceedings of the CSEE,2014,34(29):5096-5102.
[3]迟重然.燃气轮机透平冷却结构作用机制与设计优化方法[D].北京:清华大学,2014:10-13.CHI Zhongran.Mechanism and optimization methods of gas turbine cooling structures[D].Beijing:Tsinghua University,2014:10-13.
[4]阚瑞,迟重然,杨力,等.燃气轮机高温叶片内部冷却技术概述[J].热力透平,2013,42(4):260-264.KAN Rui,CHI Zhongran,YANG Li,et al.Recent developments of gas turbine internal cooling techniques[J].Thermal Turbine,2013,42(4):260-264.
[5]董素艳,刘松龄.扰流柱排内换热的实验研究[J].航空动力学报,1999,14(1):95-99.DONG Suyan,LIU Songling.Investigation on heat transfer in pin fin array[J].Journal of Aerospace Power,1999,14(1):95-99.
[6]杨成凤,张靖周,谭晓茗.水滴形叉排扰流柱阵列矩形通道内流动和换热数值模拟[J].航空动力学报,2004,19(3):361-365.YANG Chengfeng,ZHANG Jingzhou,TAN Xiaoming.Numerical simulation of flow and heat transfer in rectangular channel with staggered arrays of droplet type pin fins[J].Journal of Aerospace Power,2004,19(3):361-365.
[7]张丽,朱惠人,刘松龄,等.短扰流柱排端壁的平均换热实验[J].推进技术,2008,29(5):523-526.ZHANG Li,ZHU Huiren,LIU Songling,et al.Experiments on heat transfer in trapezoidal channel with short pin-fin arrays[J].Journal of Propulsion Technology,2008,29(5):523-526.
[8]张丽,刘松龄,刘高文.梯形和矩形通道内短扰流柱排流动与换热计算[J].推进技术,2004,25(2):107-110.ZHANG Li,LIU Songling,LIU Gaowen.Numerical simulation on heat transfer and pressure drop in pin-fin trapezoidal and rectangular duct[J].Journal of Propulsion Technology,2004,25(2):107-110.
[9]邓丁元,高行山,虞跨海,等.椭圆形扰流柱冷却通道流动与换热数值研究[J].航空动力学报,2010,25(7):1545-1552.DENG Dingyuan,GAO Xingshan,YU Kuahai,et al.Numerical simulation on flow and heat transfer of elliptical pin-fins in cooling channel[J].Journal of Aerospace Power,2010,25(7):1545-1552.
[10]贾静,王曦娟,王凯.涡轮叶片尾缘扰流柱对换热效果的影响[J].汽轮机技术,2008,50(3):220-222.JIA Jing,WANG Xijuan,WANG Kai.The effect of pin fin at trailing edge on heat transfer of turbine blade[J].Turbine Technology,2008,50(3):220-222.
[11]王龙飞,王松涛,卢少鹏,等.小高径比扰流柱冷却通道的换热和流动特性[J].航空动力学报,2015,30(6):1307-1318.WANG Longfei,WANG Songtao,LU Shaopeng,et al.Heat transfer and flow characteristics of low aspect ratio pin fins in cooling channel[J].Journal of Aerospace Power,2015,30(6):1307-1318.
[12]BAILEY J C,BUNKER R S,BAILEY J C,et al.Heat transfer and friction in channels with very high blockage45°staggered turbulators[C].ASME Turbo Expo 2003,collocated with the 2003 International Joint Power Generation Conference.2003:451-458.
[13]AMES F E,DVORAK L A,MORROW M J.Turbulent augmentation of internal convection over pins in staggered-pin fin arrays[J].Journal of Turbomachinery,2005,127(1):183-190.
[14]AMES F E,NORDQUIST C A,KLENNERT L A.Endwall heat transfer measurements in a staggered pin fin array with an adiabatic pin[C].ASME Turbo Expo 2007:Power for Land,Sea,and Air.2007:423-432.
[15]LAWSON S A,THRIFT A A,THOLE K A,et al.Heat transfer from multiple row arrays of low aspect ratio pin fins[J].International Journal of Heat&Mass Transfer,2011,54(17/18):4099-4109.
[16]ZHAO J,HUANG S,GONG L,et al.Numerical study and optimizing on micro square pin-fin heat sink for electronic cooling[J].Applied Thermal Engineering,2015,93:1347-1359.
[17]CHYU M K,SIW S C,MOON H K.Effects of height-todiameter ratio of pin element on heat transfer from staggered pin-fin arrays[C].ASME Turbo Expo 2009:Power for Land,Sea,and Air.American Society of Mechanical Engineers,2009:705-713.
[18]JASWAL I,AMES F E.Heat transfer and pressure drop measurements in constant and converging section pin and diamond pedestal arrays[J].Journal of Thermal Science&Engineering Applications,2009,1(1):757-764
[2]蒋洪德,任静,李雪英,等.重型燃气轮机现状与发展趋势[J].中国电机工程学报,2014,34(29):5096-5102.JIANG Hongde,REN Jing,LI Xueying,et al.Status and development trend of the heavy duty gas turbine[J].Proceedings of the CSEE,2014,34(29):5096-5102.
[3]迟重然.燃气轮机透平冷却结构作用机制与设计优化方法[D].北京:清华大学,2014:10-13.CHI Zhongran.Mechanism and optimization methods of gas turbine cooling structures[D].Beijing:Tsinghua University,2014:10-13.
[4]阚瑞,迟重然,杨力,等.燃气轮机高温叶片内部冷却技术概述[J].热力透平,2013,42(4):260-264.KAN Rui,CHI Zhongran,YANG Li,et al.Recent developments of gas turbine internal cooling techniques[J].Thermal Turbine,2013,42(4):260-264.
[5]董素艳,刘松龄.扰流柱排内换热的实验研究[J].航空动力学报,1999,14(1):95-99.DONG Suyan,LIU Songling.Investigation on heat transfer in pin fin array[J].Journal of Aerospace Power,1999,14(1):95-99.
[6]杨成凤,张靖周,谭晓茗.水滴形叉排扰流柱阵列矩形通道内流动和换热数值模拟[J].航空动力学报,2004,19(3):361-365.YANG Chengfeng,ZHANG Jingzhou,TAN Xiaoming.Numerical simulation of flow and heat transfer in rectangular channel with staggered arrays of droplet type pin fins[J].Journal of Aerospace Power,2004,19(3):361-365.
[7]张丽,朱惠人,刘松龄,等.短扰流柱排端壁的平均换热实验[J].推进技术,2008,29(5):523-526.ZHANG Li,ZHU Huiren,LIU Songling,et al.Experiments on heat transfer in trapezoidal channel with short pin-fin arrays[J].Journal of Propulsion Technology,2008,29(5):523-526.
[8]张丽,刘松龄,刘高文.梯形和矩形通道内短扰流柱排流动与换热计算[J].推进技术,2004,25(2):107-110.ZHANG Li,LIU Songling,LIU Gaowen.Numerical simulation on heat transfer and pressure drop in pin-fin trapezoidal and rectangular duct[J].Journal of Propulsion Technology,2004,25(2):107-110.
[9]邓丁元,高行山,虞跨海,等.椭圆形扰流柱冷却通道流动与换热数值研究[J].航空动力学报,2010,25(7):1545-1552.DENG Dingyuan,GAO Xingshan,YU Kuahai,et al.Numerical simulation on flow and heat transfer of elliptical pin-fins in cooling channel[J].Journal of Aerospace Power,2010,25(7):1545-1552.
[10]贾静,王曦娟,王凯.涡轮叶片尾缘扰流柱对换热效果的影响[J].汽轮机技术,2008,50(3):220-222.JIA Jing,WANG Xijuan,WANG Kai.The effect of pin fin at trailing edge on heat transfer of turbine blade[J].Turbine Technology,2008,50(3):220-222.
[11]王龙飞,王松涛,卢少鹏,等.小高径比扰流柱冷却通道的换热和流动特性[J].航空动力学报,2015,30(6):1307-1318.WANG Longfei,WANG Songtao,LU Shaopeng,et al.Heat transfer and flow characteristics of low aspect ratio pin fins in cooling channel[J].Journal of Aerospace Power,2015,30(6):1307-1318.
[12]BAILEY J C,BUNKER R S,BAILEY J C,et al.Heat transfer and friction in channels with very high blockage45°staggered turbulators[C].ASME Turbo Expo 2003,collocated with the 2003 International Joint Power Generation Conference.2003:451-458.
[13]AMES F E,DVORAK L A,MORROW M J.Turbulent augmentation of internal convection over pins in staggered-pin fin arrays[J].Journal of Turbomachinery,2005,127(1):183-190.
[14]AMES F E,NORDQUIST C A,KLENNERT L A.Endwall heat transfer measurements in a staggered pin fin array with an adiabatic pin[C].ASME Turbo Expo 2007:Power for Land,Sea,and Air.2007:423-432.
[15]LAWSON S A,THRIFT A A,THOLE K A,et al.Heat transfer from multiple row arrays of low aspect ratio pin fins[J].International Journal of Heat&Mass Transfer,2011,54(17/18):4099-4109.
[16]ZHAO J,HUANG S,GONG L,et al.Numerical study and optimizing on micro square pin-fin heat sink for electronic cooling[J].Applied Thermal Engineering,2015,93:1347-1359.
[17]CHYU M K,SIW S C,MOON H K.Effects of height-todiameter ratio of pin element on heat transfer from staggered pin-fin arrays[C].ASME Turbo Expo 2009:Power for Land,Sea,and Air.American Society of Mechanical Engineers,2009:705-713.
[18]JASWAL I,AMES F E.Heat transfer and pressure drop measurements in constant and converging section pin and diamond pedestal arrays[J].Journal of Thermal Science&Engineering Applications,2009,1(1):757-764