Ultrafast X-ray tomography raw-data of bubbly two-phase pipe flow around a semi-circular constriction

For the investigation of bubbly two-phase flow, which should serve as a future benchmark experiment for CFD code validation, an experimental study has been conducted at the <strong>T</strong>ransient Tw<strong>o-P</strong>hase <strong>Flow</strong> (TOPFLOW) facility at Helmholtz-Zentrum Dresden – Rossendorf (HZDR) using ultrafast electron beam X-ray tomography (UFXRAY). In this study, flow constrictions were installed into a pipe to create a generic three-dimensional flow field as an advanced test case for CFD codes. UFXRAY provide valueable data of the gas phase dynamics with high temporal and spatial resolution.

The provided data set contains tomography raw-data for the experimental series L30 that uses a <strong>semi-circular</strong> flow constriction with a blockage ratio of 0.5. 

For visualization, the data might be opend with Fiji. Therefore choose Import-&gt;Raw... In the following window specify "Image type" as 16-bit Unsigned, "Width" as 288 pixels and "Height" as 500 pixels for 2x1000Hz measurement or 200 pixels for 2x2500Hz measurement. Make sure that "Little-endian byte order" is checked. A data set contains image frames of both scanning planes in alternating order. Therefore, if only a single scanning plane is required, the offset and gap parameters need to be set to 288000 bytes for 2x1000Hz measurement or 115200 bytes for 2x2500Hz measurement.

为开展气泡两相流研究，并为计算流体动力学（Computational Fluid Dynamics，CFD）代码验证提供未来基准实验方案，研究团队于亥姆霍兹德累斯顿罗森多夫研究中心（Helmholtz-Zentrum Dresden – Rossendorf，简称HZDR）的瞬态两相流（Transient Two-Phase Flow，TOPFLOW）实验平台上，采用超快电子束X射线断层扫描（ultrafast electron beam X-ray tomography，UFXRAY）技术完成了本次实验研究。本研究在管道内加装流动缩径结构，以构建通用三维流场，作为CFD代码验证的先进测试工况。UFXRAY可获取兼具高时空分辨率的气相动力学高质量实测数据。
本次公开的数据集对应实验序列L30，该序列采用阻塞比为0.5的半圆形流动缩径结构。
若需对数据集进行可视化处理，可使用Fiji软件打开数据。具体操作流程为：依次选择「导入→原始数据」选项，在弹出的设置窗口中按如下参数配置：对于2×1000Hz采样模式，将「图像类型」设为16位无符号，「宽度」设为288像素，「高度」设为500像素；对于2×2500Hz采样模式，「高度」设为200像素。需确保勾选「小端字节序」选项。单个数据集以交替顺序存储两个扫描平面的图像帧。若仅需提取单个扫描平面的数据，则需针对2×1000Hz采样模式将偏移量与间隔参数设置为288000字节，针对2×2500Hz采样模式则设置为115200字节。