Dryout mechanism of thin liquid film near a flow obstacle using substitute fluids which simulates the high pressure and temperature conditions

气液两相流在许多工业领域中都会遇到，包括沸水堆中核燃料棒附近的流动。特别是在两个连续的扰动波之间的薄基底膜处发生水膜干涸。因此，澄清扰动波的详细行为是很重要的。在以往的研究中，许多实验都是在大气条件下进行的。然而，在大气条件下的液体和气体的性质与沸水堆操作条件（7MPa，285 ℃）下的液体和气体的性质有很大的不同。因此，本研究选择了与沸水堆工况相似的HFC 134a气体和乙醇液体作为实验流体，在较低的压力和较低的温度（0.7MPa，40 ℃）下进行实验。本文研究了气液性质对液膜厚度的影响。

Gas-liquid two-phase flow is encountered in many industries, including flow near nuclear fuel rods in boiling water reactor(BWR). Especially dryout of water film occurs at the thin base film between two successive disturbance waves. Therefore, it is important to clarify the detailed behavior of the disturbance wave. In previous studies, many experiments were performed under atmospheric condition. However the properties of liquid and gas under atmospheric condition are quite different from those of a BWR operating condition(7MPa, 285C). Therefore, in the present study, HFC134a gas and ethanol liquid, whose properties are similar to those the BWR operating conditions are used as the test fluids at comparatively low pressure and low temperature (0.7MPa,40C). In this paper, the influence of gas-liquid properties on the liquid film thickness is reported.