摘要当两件固体试件的界面互相接触时,根据实验表明,这两件固体试件发生直接接触的地方,只能在一些界面离散点或者两固体界面上的微小面积上,而且由于两个试件之间有空隙,它们两之间介质的导热系数与在这个实验中使用的固体试件导热系数,它们两者之间的导热系数相差一般很大,这样会导致上下两固体试件接触面附近的热流发生改变,这都是因导热系数相差较大而引起的,会在固体试件轴向方向产生一种热流附加阻力,这种阻力就是接触热阻。研究表明:接触热阻的产生原因是由于两固体试件相互接触界面的之间的突起,也就是固体试件接触面之间的不平整性,使得两固体试件之间界面有间隙而产生的热阻。本课题中设计了接触热阻测试的实验方案,并且跟随两位学长了解了接触热阻的实验装置及数据采集,充分利用所得的实验数据;使用vb编程及origin8.0计算分析了固体接触表面粗造度,以及界面载荷(界面接触压力)对接触热阻值的大小的影响。根据测出的热电偶数据,计算出热流密度和上下界面温度差的值,进而可以得出接触热阻的值,把以上得出的不同条件下接触热阻汇总出的实验结果可知:接触热阻值会随着界面载荷(界面接触压力)的增大而减小;随着粗造度(接触面的表面状况)的增加,两个固体试件界面间隙的增大,接触热阻的值也会随之增大 。65195
毕业论文关键词 接触热阻 上下接触面温度差 热流密度
毕业设计说明书(论文)外文摘要
Title the test of contact thermal resistance
Abstract
When two solid interface of the specimen in contact with each other, according to the experimental results show that the two pieces of the solid specimen where direct contact only at discrete points in a number of interfaces or two tiny solid area on the interface, and since the two test there is a gap between pieces, are the thermal conductivity of the medium between two and used in this experiment the solid specimen conductivity, thermal conductivity between them generally large difference, this will cause the upper and lower contact surface of the solid specimen near heat change, which are due to the thermal conductivity caused by the large difference, in the axial direction of the solid specimen to produce a heat additional resistance, this resistance is the contact resistance. Studies show that: the contact resistance generated due to two solid specimens each contact interface between the protrusions, that is, the solid specimen between the contact faces is not flat, making two solid specimens of the interface between a gap is generated thermal resistance. The issue in the design of the thermal contact resistance testing experimental program, and follow the two seniors to understand the thermal contact resistance of the experimental setup and data acquisition, take advantage of the resulting experimental data; origin8.0 using vb programming and computational analysis of solid contact surface roughness degrees, and the interface loads (interface contact pressure) on the contact thermal resistance of the size. Thermocouples according to the measured data to calculate the heat flux density and the temperature difference between the upper and lower values of the interface, then the value of the contact resistance can be obtained, the above obtained under different conditions of the contact resistance of the experimental results summarized: thermal contact as the interface resistance will load (interface contact pressure) decreases; as roughness (surface condition of the contact surface) increases, the interface of two solid specimens gap increases, the contact resistance value also increases.