求解滑移流区外掠圆柱体气流流动与传热特性的数值模型  

A Numerical Model for the Flow and Heat Transfer Characteristics of Rarefied Gas over a Cylinder in Slip Flow Regime

作　　者：谢福寿 雷刚[1] 邱一男 徐元元 王天祥 厉彦忠 XIE Fushou;LEI Gang;QIU Yinan;XU Yuanyuan;WANG Tianxiang;LI Yanzhong(State Key Laboratory of Technologies in Space Cryogenic Propellants,Beijing 100028,China;School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]航天低温推进剂技术国家重点实验室,北京100028 [2]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2019年第1期25-32,共8页Journal of Xi'an Jiaotong University

基　　金：航天低温推进剂技术国家重点实验室开放课题(SKLTSCP1610);中国博士后科学基金资助项目(2018M633505);国家自然科学基金资助项目(51876153);陕西省博士后科研资助项目

摘　　要：为了更精确地求解滑移流区稀薄气体外掠圆柱体流动与传热问题,基于有限容积法的ANSYS FLUENT平台提出了一种滑移边界修正的数值模型,该模型考虑了完整的一阶速度滑移和温度跳跃,其中一阶速度滑移包括了轴向温度引起的热蠕动影响和壁面曲率影响。将模型计算值与实验数据进行了充分对比,结果表明:当气体流动处于连续流区时,滑移边界修正模型与无滑移边界直接模拟计算误差很小;当气体流态处于滑移流区时,采用滑移边界修正模型可实现对该流态气体流动与传热的精确预示(相对误差在±2.5%);稀薄效应对低压气体外掠圆柱体的流动特性影响显著,随着克努森数增加,最大无量纲滑移速度呈线性增加,而最大表面摩擦系数呈线性降低。本文方法可广泛应用于工程之中,以探索低压气体的换热机理,为研究稀薄气体滑移流区流动与传热问题提供了一种有效的数值计算方法。To more accurately solve the problem of rarefied gas flow and heat transfer over a cylinder in slip flow regime,based on the ANSYS FLUENT platform of finite volume method,a modified numerical model of slip boundary is proposed.The first-order velocity slip and temperature jump are considered in this model,and the first-order velocity slip includes the effects of the thermal creep caused by axial temperature and the curvature of wall surface.Compared with experimental data,the errors of the values calculated by modified model of slip boundary and by direct simulation without slip boundary are very small when the rarefied gas flow is in the continuous flow regime.The precise prediction of flow and heat transfer characteristics can be achieved by using the present model,and the relative error is ±2.5% when the rarefied gas flow is in the slip flow regime.Rarefying effect has significant influence on the flow characteristics of low pressure gas over a cylinder.With the increase of Knudsen number,the maximum dimensionless slip velocity increases linearly,while the maximum surface friction coefficient decreases linearly.This method can be widely used in engineering to explore the heat transfer mechanism of low pressure gases,and may become an effective numerical method for the study on the flow and heat transfer of rarefied gases in slip flow regime.

关 键 词：滑移流区 稀薄气体 数值模拟 流动与传热 圆柱体 

分 类 号：V511[航空宇航科学与技术—航空宇航推进理论与工程]