Condensation Phenomena in Heat Pipes and Thermosyphons

热管是仅以很小的热通量传输热量的装置。 阻力 这种特性是相变的结果 过程--蒸发和冷凝--发生在过程的两端 烟斗 热管高效运行的关键问题 是两端之间的蒸汽和液体的传输。 该提案涉及影响气候变化的三个基本问题 热管的运行：（1）不凝性气体的分布 和其它气态或蒸气物质，（2）在冷凝器中的蒸气冷凝， 芯结构，其放置在热管中以促进液体 传输，以及（3）启动、关闭和 热负荷的变化。 拟议的研究包括一系列 建模工作，每一个结构，包括以前未考虑 现象。 为了便于包含这些效应，积分 形式的守恒方程将被使用，而不是更多的 复微分形式 将进行实验以支持 并验证分析预测。

Heat pipes are devices which transport heat with only a small thermal resistance. This characteristic is the result of phase change processes--evaporation and condensation--which occur at either end of the pipe. Critical issues in the efficient operation of a heat pipe are the transport of vapor and liquid between the ends. The proposal deals with three fundamental issues which affect the operation of heat pipes: (1) the distribution of noncondensable gases and other gaseous or vapor species, (2) condensation of vapor in the wick structure that is placed in the heat pipe to facilitate liquid transfer, and (3) transient effects during start-up, shut-down, and changes in heat load. The proposed research consists of a succession of modeling efforts, each structured to include previously unaccounted phenomena. To facilitate the inclusion of these effects, the integral forms of the conservation equations will be used rather than the more complex differential forms. Experiments will be performed to support and verify the analytical predictions.