封闭腔内置倾斜换热管的自然对流数值模拟  

Numerical Simulation of Natural Convection in Enclosed Rectangular Cavity with Built-in Inclined Tubes

作　　者：周梦 虞斌[1] 涂善东[1,2] ZHOU Meng;YU Bin;TU Shan-Dong(School of Mechanical and Power Engineering,Nanjing University of Technology;School of Mechanical and Power Engineering,East China University of Science and Technology)

机构地区：[1]南京工业大学机械与动力工程学院 [2]华东理工大学机械与动力工程学院

出　　处：《化工机械》2018年第5期636-642,共7页Chemical Engineering & Machinery

摘　　要：数值模拟了封闭腔内置倾斜换热管的自然对流流动与换热。研究了瑞利数Ra(104～107)、换热管倾角θ(30～75°)、方腔高宽比A(3/5,1,5/3)条件下方腔内温度场、流场和换热管表面平均努塞尔数Nuav的变化规律。结果表明:换热管表面平均努塞尔数随着瑞利数的增大而增大,换热机理由导热逐渐过渡到对流换热,换热能力逐渐加强;随着换热管倾角的增大,方腔内的流动结构由双涡结构转变为单涡结构,平均努塞尔数与倾角呈递增关系,换热能力加强;随着方腔高宽比的减小,流动结构略有不同,由于方腔顶部二次涡的产生,使得流动换热加强。Numerical investigation of free convection flow and heat transfer in enclosed cavity with built-in inclined tubes was implemented, including study of the change rule of both temperature field and flow field with- in the rectangular cavity and average Nusseh number Nuav under the condition that Rayleigh number Ra was 104 to 107 , the cylinder inclination 0 was 30° to 75° and the enclosure aspect ratio A was 3/5,1 and 5/3 respectively. The simulation results show that, the average Nusseh number Nuav grows with the increase of Rayleigh number Ra ; and the heat transfer mechanism transforms from heat conduction to heat convection gradually and heat capacity is gradually strengthened; the flow structure within the rectangular cavity transforms from a double vortex structure to a single vortex structure with the increase of inclination 0 of inclined tube ; the heat capacity can be gradually strengthened when the average Nusseh number Nuav and inclination 0 increase progressively. When the aspect ratio A decreases, the flow structure is slight different and the secondary vortex occurred in the cavity top can strengthen the flow and heat transfer.

关 键 词：封闭方腔 倾斜换热管 自然对流 数值模拟 

分 类 号：TQ051[化学工程]