EVAPORATION FROM AN EXTENDED MENISCUS FOR NONISOTHERMAL INTERFACIAL CONDITIONS
EVAPORATION FROM AN EXTENDED MENISCUS FOR NONISOTHERMAL INTERFACIAL CONDITIONS
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DOI：
10.2514/3.602
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发表时间：
1994-10-01
影响因子：
2.1
通讯作者：
CHANG, WS
中科院分区：
文献类型：
--
作者：
HALLINAN, KP;CHEBARO, HC;CHANG, WS
本文研究了热管多孔芯或槽芯微孔内液-气半月板薄膜区蒸发对界面形状、温度分布和压力分布的影响。韦纳对蒸发薄膜的理论处理适用于圆形或开槽孔内蒸发扩展半月板的问题。在韦纳模型的应用中，无因次动量方程是根据毛细数进行唯一缩放的，以证明即使在本文研究的动态蒸发条件下，也可以使用静态半月板曲率作为扩展半月板剖面的边界条件。小毛细数的边界条件与薄膜必须渐近接近的随蒸发速率变化的半月板曲率几乎恒定的观测结果是一致的。从这些基本原理出发，预测了稳定、蒸发、非等温扩展半月板的力学和热行为。由此得出的预测与Wavner的实验结果和先前的理论研究在质量上是一致的。他们进一步支持这样的说法，即对于本文所研究的情况，在液-气界面上的热毛细管应力和蒸汽反冲应力都可以忽略不计。然而，提出了确定这些术语重要的必要条件的缩放论证。
A study is presented to determine the effects of evaporation from the thin film region of a liquid-vapor meniscus within the micropores of a heat pipe porous or grooved wick on the interfacial shape, temperature distribution, and pressure distribution. Wayner's theoretical treatment of evaporating thin films is applied to the problem of an evaporating extended meniscus within circular or slotted pores. In this application of Wayner's model, the nondimensional momentum equation is uniquely scaled in terms of the capillary number, to justify the use of the static meniscus curvature as a boundary condition for the extended meniscus profile even for the dynamic evaporating conditions studied herein. This boundary condition for small capillary numbers is consistent with (he observation of the nearly constant meniscus curvature with evaporation rate that the thin film must asymptotically approach. From these basic tenets, the mechanical and thermal behavior of a stably, evaporating, nonisothermal extended meniscus is predicted. The resulting predictions are qualitatively consistent with the experimental findings of Wavner and the previous theoretical studies. They further support the claims that for the cases studied herein, both thermocapillary stresses and vapor recoil stresses at the liquid-vapor interface are negligible. However, scaling arguments are presented that identify the conditions necessary for these terms to be important.