Abstract

In the paper, the results of tests on pool boiling heat transfer on open microchannel surfaces were discussed. Nucleate pool boiling from copper microchannel surfaces was examined using ethanol as a working fluid. Parallel microchannels fabricated by machining were about 0.2 to 0.4 mm wide and 0.2 to 0.5 mm deep. In the mathematical model the heat transfer process was in steady state. The heat transfer in copper block was assumed axisymmetric while the specimen temperature distribution was not. The temperature of the copper block and the specimen were assumed to satisfy Laplace’s equations with adequate boundary conditions. The problem was solved by the Trefftz method with two sets of Trefftz functions. Graphs were used to represent the copper block and the specimen temperature distributions, local values of heat transfer coefficients as a function of the heat flux and fin temperature distribution. Uncertainty analysis was presented.

摘要

文中讨论了开放微通道表面池沸腾传热试验的结果。使用乙醇作为工作流体检查从铜微通道表面沸腾的核池。通过机械加工制造的平行微通道大约为 0.2 至 0.4 毫米宽和 0.2 至 0.5 毫米深。在数学模型中，传热过程处于稳定状态。铜块中的传热假定为轴对称，而试样温度分布则不是。假设铜块和试样的温度满足拉普拉斯方程和足够的边界条件。使用两组Trefftz 函数的Trefftz 方法解决了这个问题。图表用于表示铜块和试样温度分布，传热系数的局部值作为热通量和翅片温度分布的函数。提出了不确定性分析。