热肋片宽度对复杂方腔自然对流影响的数值分析  

Numerical analysis of the hot fin's width effect on natural convection of air enclosed in a 2D complex square cavity

作　　者：王小华[1] 魏英杰[2] 朱文芳[3] 

机构地区：[1]浙江大学航空航天学院流体工程研究所,杭州310027 [2]哈尔滨工业大学航空航天学院,哈尔滨150090 [3]浙江科技学院建工学院,杭州310012

出　　处：《计算力学学报》2011年第3期383-387,共5页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(50708030)资助项目

摘　　要：采用笔者等发展的二阶全展开Euler-Taylor-Galerkin分裂步有限元方法,经过对算法精度验证,在确定不同网格密度对计算结果影响的基础上,确定出计算所需网格密度的必要条件,并在指定的网格密度条件下,分析了热肋片宽度对封闭方腔内典型自然对流流动的影响,流动对应的Pr=0.71,Ra=104。计算结果表明,随热肋片宽度的增加,方腔平均Nu数呈现出先减小后增加的趋势,转折点肋宽约为0.7,对应涡核从一个变为两个。By using a second order Euler-Taylor-Galerkin（ETG） finite element method of fractional steps,numerical analysis of the hot fin＇s width effect on natural convection of air enclosed in a 2D square cavity was carried out while keeping Pr=0.71.Code validation and mesh resolution effect estimation were conducted firstly.As the presented results agreed well with the benchmark ones provided by some literatures for natural convection of air enclosed in a square cavity,it was proved that the second order ETG method can be used in the computation.Moreover,as the results shown,in order to consider the grid independence,at least 80×80uniform square elements must be used.Grid of 100×100uniform square elements was then used to analyze the hot fin＇s width effect on natural convection of air enclosed in a 2D complex square cavity.It was found that the hot fin＇s width（W/B） had great influences on the flow characteristics.The averaged Nu decreased firstly with the increase in W/B.However,when W/B is higher than about 0.7,the averaged Nu increased then with further increase in W/B.Furthermore,it is observed that the flow patterns bifurcated from steady unicellular structure to steady bi-cellular structure correspondingly.

关 键 词：热肋片 肋片宽度 复杂方腔 自然对流 网格密度 

分 类 号：O357[理学—流体力学]