The multiscale boiling project, also known as RUBI, is an experimental project supported by the European Space Agency (ESA) focusing on the nucleate boiling within the framework of the utilization of the International Space Station (ISS). In order to investigate the operational behavior of the experimental components and determine a promising parameter range, an experimental setup with the same heater design is constructed and tested within the similar parameter range in the framework of the ESA 70^th parabolic flight campaign. The present work introduces the experimental setup as well as the measurement methodologies. It concentrates on the results obtained for the nucleate boiling in the absence of external forces such as electric field or shear flow, which are also part of the multiscale boiling project. A barium fluoride glass sputtered with chromium on the top of a chromium nitride layer served as the heater. The manufacturing process of the heater substrate is presented in detail. In order to generate a vapor bubble in the subcooled liquid pool, a laser beam is used to provide the necessary heat at an artificial nucleation site situated at the center of the glass. The experimental setup allows for time adjustment between switch-on of the heater and shooting the laser which is defined as preheating time. The effect of the preheating time on the nucleation and behavior of the bubbles is investigated. Furthermore, by selecting a long laser pulse duration the influence of the laser thermal energy on the growth of the bubbles is studied. It is observed that the preheating time has a significant effect on the bubble growth. However, no influence of the laser shot is detected on the bubble growth, even for a long pulse duration.

中文翻译：

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微重力下单泡核沸腾的实验研究

在多尺度沸腾的项目，也被称为RUBI，是由欧洲航天局（ESA）支持的实验项目，重点泡核沸腾国际空间站（ISS）的使用范围内。为了调查实验组件的操作行为并确定一个有希望的参数范围，在ESA^第70^届抛物线飞行战役的框架内，在相同参数范围内构造并测试了具有相同加热器设计的实验装置。本工作介绍了实验装置以及测量方法。它着重于在不存在外力（例如电场或剪切流）的情况下进行核沸腾的结果，这也是其中的一部分多尺度沸腾项目。在氮化铬层的顶部溅射有铬的氟化钡玻璃用作加热器。详细介绍了加热器基板的制造过程。为了在过冷的液体池中产生蒸气气泡，使用激光束在位于玻璃中心的人工成核位置提供必要的热量。实验设置允许在加热器打开和发射激光之间进行时间调整，这被定义为预热时间。研究了预热时间对气泡形核和行为的影响。此外，通过选择较长的激光脉冲持续时间，研究了激光热能对气泡生长的影响。可以看出，预热时间对气泡的生长有重要影响。然而，