竖直通道内水平管束自然对流的数值模拟  

Numerical Simulation of Natural Convection over a Column of Cylinder in a Vertical Channel

作　　者：代明俊 王治云[1] Dai Mingjun;Wang Zhiyun(College of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《山东化工》2020年第13期204-207,230,共5页Shandong Chemical Industry

摘　　要：采用非稳态的层流模型对竖直通道内水平管束的自然对流换热进行了数值模拟。分析了管间距以及瑞利数的变化对管束自然对流的流动和换热特性的影响。数值模拟结果表明:随着管间距和瑞利数的增大,管间的流动由稳定的对称状态逐渐发展为随时间的周期震荡状态和混沌的震荡状态,并给出了管后所有对称流动状态消失的临界管间距和瑞利数。圆管换热在瑞利数较小时随管间距的增大变化较小,当瑞利数在106≤Ra≤108范围时,圆管换热总体随管间距的增大而减小。Numerical simulation is performed by adopting transient mode for the natural convection around a bundle of horizontal cylinders confined in a vertical channel.The influence of the longitudinal pitch between the cylinders and Rayleigh number on the flow and heat transfer and characterization is analyzed.The numerical results show that,the flow between cylinders developed from stable and symmetrical state to periodic oscillation state and unstable oscillation with the increase of the longitudinal pitch and Rayleigh number,and obtained the critical Rayleigh number and longitudinal pitch where the symmetric and stable flow disappeared.The change of heat transfer between the cylinders was weak with the increase of the longitudinal pitch when the Rayleigh number was smaller but obviously while the Rayleigh number larger and become regular.

关 键 词：圆管束 自然对流 数值模拟 管间距 瑞利数 

分 类 号：TQ018[化学工程]