间隙自然对流对单点接触热阻的影响研究  

Study on the Effect of Natural Convection of Clearance on Single-point Contact Thermal Resistance

作　　者：秦佳佳 王安良[1] QIN Jiajia;WANG Anliang(School of Astronautics Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学宇航学院,北京100191

出　　处：《工程热物理学报》2025年第4期1261-1269,共9页Journal of Engineering Thermophysics

摘　　要：本文数值模拟了受间隙介质自然对流作用下热流管模型的传热特性,采用一般计算方法和界面热阻网络模型计算扩散(或收缩)热阻,研究了尺寸、物性参数和边界条件对单点接触热阻的影响规律;进一步分析了半径比、高径比和气固导热系数比,三种无量纲因子对单点接触热阻的影响。结果表明:间隙存在气体介质时,在自然对流作用下单点接触热阻随半径比的变化规律与真空条件下变化趋势相似;因间隙介质传导和对流使得单点接触热阻小于相同工况的真空值,且半径比越小,介质漏热的影响越明显;当半径比为0.2时,对流作用下的无量纲扩散热阻值与真空环境下比较,相对减小超过15%。对一般工程条件,改变热流密度、热源温度和冷却温度,模拟的无量纲扩散热阻值的变化不超过3%,验证了模型的鲁棒性。通过非线性拟合出无量纲扩散热阻受三种无量纲因子影响的公式,对实际工程具有应用价值。In this paper,the heat transfer characteristics of the heat flow pipe model under the natural convection of the gap medium are simulated,the spreading resistance is calculated by using the general calculation method and the interface thermal resistance network model,and the influence of size,physical properties parameters and boundary conditions on the thermal resistance of single-point contact is studied;the influence of three dimensionless factors,namely,radius ratio,height-diameter ratio,and gas-solid thermal conductivity ratio under convection,is further analyzed.The results show:When there is a gas medium in the gap,the change law of the thermal resistance of the single-point contact with the radius ratio under the action of natural convection is similar to the changing trend under vacuum conditions,but due to the conduction and convection of the gap medium,the single-point contact thermal resistance is less than the vacuum value of the same condition,and the smaller the radius ratio,the more obvious the influence of the medium heat leakage.When the radius ratio is 0.2,the dimensionless spreading resistance value under convection action is reduced by more than 15%compared with that in a vacuum environment.For general engineering conditions,when changing the heat flux density,heat source temperature and cooling temperature,the simulated dimensionless spreading resistance value changes by no more than 3%,which verifies the robustness of the model.Finally,the formula of dimensional spreading resistance affected by three dimensionless factors is obtained by nonlinear fitting,which has application value for practical engineering.

关 键 词：自然对流 单点接触热阻 扩散热阻 收缩热阻 界面热阻网络模型 

分 类 号：TK124[动力工程及工程热物理—工程热物理]