Thermophysical characteristics of a wickless heat pipe in microgravity - Constrained vapor bubble experiment
Thermophysical characteristics of a wickless heat pipe in microgravity - Constrained vapor bubble experiment
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DOI：
10.1016/j.ijheatmasstransfer.2014.07.044
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发表时间：
2014-11-01
影响因子：
5.2
通讯作者：
Wayner, Peter C., Jr.
中科院分区：
文献类型：
--
作者：
Kundan, Akshay;Plawsky, Joel L.;Wayner, Peter C., Jr.
目前正在研究用于冷却航天器关键部件的无芯热管。无芯设计被认为产生比包含芯的热管或机械驱动系统更简单和更轻的传热系统。约束汽泡实验（CVB）是在国际空间站上测试的一个这样的系统，其中邦德数（重力与表面力的比率）很小，使毛细作用的影响最大化。CVB基本上是一个方形的熔融石英分光光度计比色皿，抽空后部分填充戊烷作为工作流体。沿着温度和压力测量，使用包含在站的光学显微镜模块（LMM）中的基于干涉测量的系统来确定在石英比色皿的拐角处形成的纳米颗粒的二维厚度轮廓。CVB可以被看作是一个空心翅片和它的行为分析使用一个简单的，一维的传热模型。该模型结合对翅片内部汽液分布的直观观察，加深了对测量的温度和压力分布所代表的内容以及控制装置运行的传热机制的理解，发现内部传热过程是非常复杂的、多维的，并且在很大程度上依赖于内部和外部的辐射传热。内部辐射交换被认为是更显着的比原来预期的是马兰戈尼力的影响，内部对流传热。结合汽-液界面映射的温度分布的分析表明，该系统可以被分成一些离散的操作区，这取决于传热的主导模式。(C)2014爱思唯尔有限公司版权所有。
Wickless heat pipes are being studied for use in cooling critical components of spacecraft. The wickless design is thought to produce a simpler and lighter heat transfer system than heat pipes containing wicks or mechanically driven systems. The constrained vapor bubble experiment (CVB) is one such system tested on the International Space Station where the Bond Number (ratio of gravitational force to surface force) is small maximizing the affects of capillarity. The CVB is essentially a square, fused silica spectrophotometer cuvette evacuated and then partially filled with pentane as the working fluid. Along with temperature and pressure measurements, the two-dimensional thickness profile of the menisci formed at the corners of the quartz cuvette was determined using an interferometry based system contained with the station's Light Microscopy Module (LMM). The CVB can be viewed as a hollow fin and its behavior analyzed using a simple, one-dimensional heat transfer model. That model, coupled with the visual observation of the vapor-liquid distribution inside the fin, provides an enhanced understanding of what the measured temperature and pressure profiles represent and the heat transfer mechanisms controlling the operation of the device.The internal heat transfer processes were found to be very complicated, multi-dimensional, and greatly dependent on internal and external radiative heat transfer. Internal radiative exchange was found to be more significant than originally anticipated as was the effect Marangoni forces on internal convective heat transfer. An analysis of the temperature profiles in conjunction with vapor-liquid interface mapping showed that the system could be separated into a number of discrete operation zones depending on the dominant mode of heat transfer. (C) 2014 Elsevier Ltd. All rights reserved.