水平槽道内几种周期性结构的传热与流动研究  

Numerical Investigation of Heat Transfer and Flow of Several Periodical Structures in Horizontal Channel

作　　者：汪健生[1] 李康宁[1] 

机构地区：[1]天津大学机械工程学院,天津300072

出　　处：《机械工程学报》2011年第18期144-151,共8页Journal of Mechanical Engineering

摘　　要：采用数值模拟方法,对流体在不同周期性结构二维水平槽道内的传热性能与流动特性进行研究。分析不同雷诺数条件下,布置于槽道下壁面的障碍块表面时均努塞尔数Nu及表面摩擦因数μ的变化规律。计算结果表明,当障碍块之间量纲一距离分别为0.50和0.25、雷诺数Re=1 000时;槽道上、下壁面均布置障碍块的传热性能较仅在槽道下壁面布置障碍块的传热性能有了显著提高,前者比后者的传热性能分别提高393%和574%。当雷诺数Re=500、障碍块之间量纲一距离为0.50时,对在槽道中间设置一斜板与不设置斜板两种情况进行比较后发现,设置斜板的槽道比不设置斜板的槽道传热性能提高27.1%。当在下壁障碍块右上角处放置一小圆柱体后发现:传热性能并未得到有效提高,但流动摩擦因数有所减小,从而使得输送流体的泵功降低。Two-dimensional numerical simulation has been performed for flow and heat transfer for multiple geometric constructions in horizontal channel.Close attention is paid to time-averaged whole Nusselt number and skin friction coefficient on the bottom block exposed surfaces with different Reynolds numbers.It is found that heat transfer enhancement is up to 393% and 574% respectively in the value of Nusselt number,when the blocks are periodically mounted on top and bottom channel walls for Ls=0.5 and Ls=0.25,compared to the blocks mounted only on the bottom wall at Re=1 000.In addition,when insertion of an oblique plate between the upper and lower blocks for Ls=0.50 is compared to that of the case without an oblique plate,heat transfer is enhanced 27.1% at Re=500.However,the presence of a small cylinder which is fixed on over the right corner of the lower obstacle does not make the heat transfer enhancement as compared to that of the case without a small cylinder.But the skin friction coefficient is decreased,then the fluid-feed pumping power is reduced.

关 键 词：传热 流动摩擦因数 周期模型 

分 类 号：TK124[动力工程及工程热物理—工程热物理]