Study on the Dynamic Thermal Contact Resistance and Its Evaluation

动态接触热阻的研究及其评价

基本信息

批准号：
12650195
负责人：
TORII Kahoru
金额：
$ 2.56万
依托单位：
Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650195/
关键词：
Heat Conduction Thermal Contact Resistance Dynamic Thermal Resistance Transient Method Numerical Analysis Constriction Resistance Rarefied Gas Effect 最適化ニューラルネットワーク

项目摘要

This study aims at understanding the physical mechanisms of dynamic thermal contact resistance (TCR) of cylindrical surfaces in rolling contact. As a first step to clarifying this complex phenomenon, the TCR of statically-contacting cylindrical surfaces has been investigated in detail. A transient method for the evaluation of TCR is developed with a view to applying it to the dynamic case. The technique is used to estimate the value of TCR for rollers made of either steel (S45C) or aluminum alloy (A6061). A series of experimental and computation evaluations is made for TCR of contacting rolls, whose dimension is 60 mm in diameter and 180 in length, under the loading conditions of 10-120 kgf(98-1 1 80 N). The conclusions gained by the present study are summarized as follows :(1) The total TCR measured and estimated decreases with load applied to the rollers.(2) Microscopic constriction resistance at a contact line becomes negligible for the load larger than 20 kgf under the present cond … More itions. Instead, macroscopic constriction resistance due to the heat flow's converging to the contact line becomes dominant in overall TCR.(3) This macroscopic constriction resistance is dependent on the width of the contact line. The width is estimated to be about 1.4-2.4 mes, the value given by the Hertz theory of elastic contact. This discrepancy is likely due to the roughness present on the surfaces.(4) The conduction heat transfer through the air present between the contacting surfaces has an important contribution to the overall heat transfer. The consideration of the rarefied gas effect is also important for very thin air layer near the contact line(5) The effect of heat capacity of the contact resistance layer responsible for the microscopic constriction resistance can be neglected.This suggests that the overall dynamic TCR of cylindrical surfaces in rolling contact may be evaluated from the static microscopic TCR plus the dynamic macroscopic TCR, the latter can be predicted numerically by conventional computational methods. Less

本研究旨在了解滚动接触中圆柱表面动态热接触电阻 (TCR) 的物理机制，作为阐明这一复杂现象的第一步，我们对静态接触圆柱表面的 TCR 瞬态方法进行了详细研究。开发用于评估 TCR 的技术是为了将其应用于动态情况，该技术用于估算由钢 (S45C) 或铝合金制成的滚子的 TCR 值。 (A6061)对直径60mm、长度180的接触辊TCR在10-120kgf(98-1 1 80 N)的载荷条件下进行了一系列的实验和计算评估。本研究获得的结果总结如下：(1) 测量和估计的总 TCR 随着滚子上施加的负载而减小。(2) 接触线处的微观收缩阻力在当前条件下，对于大于 20 kgf 的负载，可以忽略不计。相反，由于热流会聚到接触线而产生的宏观收缩阻力在总体 TCR 中占主导地位。(3) 这种宏观收缩阻力取决于宽度。接触线的宽度估计约为 1.4-2.4 米，该值是由赫兹弹性接触理论给出的。 (4) 通过接触表面之间存在的空气进行的传导热传递对整体热传递具有重要贡献，对于接触线附近的非常薄的空气层而言，考虑稀薄气体效应也很重要(5)。负责微观收缩阻力的接触阻力层热容量的影响可以忽略不计。这表明滚动接触圆柱表面的整体动态TCR可以通过静态微观TCR加上动态宏观TCR来评估，后者可以被预测通过传统的计算方法进行数值计算。