带有方形挡板的后台阶通道的瞬态数值分析  

Numerical analysis of pulsating flow in a channel with backward-facing step mounting a square baffle

作　　者：崔媛媛[1] 刘焕玲[1] 孙恒[1] 刘平[1] 

机构地区：[1]西安电子科技大学机电工程学院,陕西西安710071

出　　处：《内蒙古科技大学学报》2017年第2期151-159,共9页Journal of Inner Mongolia University of Science and Technology

基　　金：中央高校基本科研业务费基金资助项目(7214418102)

摘　　要：利用Fluent软件研究了后台阶上表面固定方形挡板的瞬态层流的换热特性.工作流体选用水-二氧化硅纳米流体,分析了挡板距离、挡板宽度、入口处速度的振幅(0.25~1)和频率(0.01~1 Hz)对后台阶换热效果的影响.结果表明,通过提高脉动的振幅可以提高换热效果.在雷诺数Re=100,400,振幅A=1时,瞬态平均努塞尔数和强化换热值(HTE)均随着频率的增加先增大后减小,存在最佳频率值.同时从场协同原理角度分析强化换热的效果,结果表明雷诺数Re=400时,频率f=0.1 Hz、挡板距离D=1(D是优化挡板无量纲距离,后文简称"挡板距离)的场协同角最小,换热效果最好.The heat transfer in a backward-facing step with a square baffle mounted on its top wall was numerically simulated in laminar pulsating flow using Fluent software. Using water-SiO2 nanofluid, the effects of baffle distance, baffle width, pulsating amplitude （0. 25 - 1 ） and frequency （0. 01 - 1Hz） on heat transfer characteristics were analyzed numerically. Result indicates that increasing the amplitude of the pulsation enhances heat transfer. The time-averaged Nusseh number and the value of heat transfer enhancement increased first up to an optimal frequency and then smoothly decreased with the increase of frequency at Re = 100, A = 1 and Re = 400, A = 1 , respectively. The heat transfer was studied by using the field synergy principle. The result shows that the smallest field synergy angle ap- pears with the best heat transfer effect at the frequency of 0.1 Hz, baffle distance of D = 1.5 for Re = 400.

关 键 词：瞬态流动 后台阶 方形挡板 场协同 

分 类 号：TK124[动力工程及工程热物理—工程热物理]