摘要
以椭圆管加热水流动为研究对象,对椭圆管加热水流动系统进行了二维数值模拟。通过联立求解流体力学基本方程和熵产方程,获得了熵产、放热系数与雷诺数和纵、横向间距的变化关系。数值分析结果表明:熵产主要发生在管壁表面附近,而在系统内部区域熵产较小,可以忽略;熵产随雷诺数的增大而增大,随纵、横向间距增加而减小,熵产与雷诺数、纵、横向间距存在对应关系,纵、横向间距宜在1.75～2.0间;在相同的雷诺数值时,熵产、放热系数沿流动方向呈现单调减小的趋势;不同的雷诺数值,熵产、放热系数不同,单调减小的趋势相同。放热系数随Re的增大而增大,且与雷诺数存在对应关系。纵向总放热系数随纵、横向间距增大而减小,且存在对应关系。
This paper used water flow heated in elliptical tube as research object and made two-dimensional numerical simulation of water flow heated elliptical tube system.Through the simultaneous solution of fluid mechanics basic equation and entropy production equation,it got the variation relation between the entropy production,heat transfer coefficient and Re and vertical and horizontal distance.The results of numerical analysis shown that entropy production mainly appears near the surface of the wall and entropy production in the interior area of system is smaller,which can be ignored.Entropy production increases with the increase of Re and decreases with the increase of vertical and horizontal distance.There exists corresponding relation between entropy production and Re and vertical and horizontal distance.The appropriate vertical and horizontal distance is from 1.75 to 2.0.In the same Re,entropy production and heat transfer coefficient decreases along flowing direction.There are different entropy production and heat transfer coefficient with different Re and trend of monotonic decreases is same.Heat transfer coefficient increases with the increase of Re,which has corresponding relation with Re.Vertical total heat transfer coefficient decreases with the increase of vertical and horizontal distance and there is corresponding relation.
出处
《水资源与水工程学报》
2011年第6期133-136,共4页
Journal of Water Resources and Water Engineering
关键词
椭圆管
熵产
放热系数
数值分析
对应关系
elliptical tube
entropy generation
heat transfer coefficient
numerical analysis
corresponding relation
