Void fraction distribution is an essential parameter for the design and development of nuclear reactors. In this work, void fraction measurements have been performed on an experimental setup mimicking the flow behavior in a calandria of Boiling Water Reactor (BWR). Experimental measurements for void fraction distribution were performed on three heater rods configurations at fixed electrical power using non-invasive gamma-ray densitometry at varying inlet liquid flow rates and temperatures. The main focus of this contribution was to measure void fraction distribution of boiling flows in a test section having the arrangement to accommodate different heater rods configurations by keeping the mechanical aspects of the gamma-ray densitometry technique simple. Measurements were done at four axial locations. and at each axial location, void fraction measurement was performed at eight radial locations. Experimental results show that void fraction profiles are not only influenced by the configuration of heater rods but also by the operating conditions. The void fraction profiles of configuration A were flat as compared to all other heater rod configurations. The data reported here help develop CFD models and understand the dependence of void fraction distribution on heater rods configuration.

空隙率分布是核反应堆设计和开发的重要参数。在这项工作中，已经在模拟沸水反应堆 (BWR) 排管中流动行为的实验装置上进行了空隙率测量。在不同的入口液体流速和温度下，使用非侵入式伽马射线密度测定法在固定电功率下对三个加热棒配置进行了空隙率分布的实验测量。这项贡献的主要重点是通过保持伽马射线密度测量技术的机械方面的简单性来测量测试部分中沸腾流的空隙率分布，该部分具有适应不同加热棒配置的安排。在四个轴向位置进行测量。在每个轴向位置，在八个径向位置进行空隙率测量。实验结果表明，空隙率分布不仅受加热棒配置的影响，还受操作条件的影响。与所有其他加热棒配置相比，配置 A 的空隙率分布是平坦的。此处报告的数据有助于开发 CFD 模型并了解空隙率分布对加热棒配置的依赖性。