流动冲击角对流体绕流管束换热的影响-《郑州大学学报(工学版)》

文章信息/Info

Title:: Influence of Flowing Impact Angle Heat Transfer in Fluid Flowing Across Tube Bundles

作者:: 董其伍; 王烨; 刘敏珊.; 郑州大学,热能工程研究中心,河南,郑州,450002, 郑州大学,热能工程研究中心,河南,郑州,450002, 郑州大学,热能工程研究中心,河南,郑州,450002

Author(s):: DONG Qiwu; WANG Ye; LIU Minshan; Thermal Energy Engineering Research Center，Zhengzhou University，Zhengzhou 450002，China

Keywords:: flowing impact angle; flow across tube bundle; local heat transfer; numerical simulation

摘要:: 运用计算流体动力学软件FLUENT,对流动冲击角分别为45°、60°、75°和90°,流体绕流6排87根错排管束下的换热进行三维数值模拟.管束的纵向和横向管间距分别为9.5 mm和11 mm.考查管束的平均换热努赛尔数和模型进出口压降,并与茹卡乌斯卡斯的实验关联式进行对比,当雷诺数为5 000～20 000时,给出4种流动冲击角下管束换热努赛尔数的拟合公式,并对管周向局部换热特点进行细观分析.结果表明:湍流边界层在周向夹角为大约105°时从管壁面分离,此时换热最差;流动冲击角越大,管束的平均换热努赛尔数和模型进出口压降越大;流动冲击角为45°时综合换热性能较好.

Abstract:: Three—dimentional numerical simulation on heat transfer in fluid flowing across tube bundles iscarried out by using the computational fluid dynamics software FLUENT，while the totle tube bundles are 87 intubes staggered arrangement with the specific flowing impact angles of 45°，60°，75°and 90°．The longitudinaland transverse tube pitch is 9．5 mm and 1 1 mm，respectively．The numerical simulation results of the averageheat transfer Nusseh number and the pressure drop from the inlet to outlet of models are investigated and com—pared with)Kykayckac’S experimental correlation．With the Reynolds numbers from 5 000 to 20 000 in thispaper，the fitting formula of the average heat transfer Nusseh number is given for different impact angles．Thelocal heat transfer character in the circumferential direction along tube walls is also analyzed in detail．Itshowed that，the turbulent boundary layer separates from tube walls when the circumferential angle is about105 °，when the heat transfer coefficient is the lowest；the average heat transfer Nusseh number and pressuredrop become bigger as the flowing impact angles increase．The comprehensive heat transfer performance ismuch better when the flowing impact angle is 45°