A new algorithm for segmentation of ultrafast X-ray tomographed gas–liquid flows
A new algorithm for segmentation of ultrafast X-ray tomographed gas–liquid flows
复制标题
超快 X 射线断层扫描气液流分割的新算法
DOI：
10.1016/j.ijthermalsci.2014.12.015
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发表时间：
2015
影响因子：
4.5
通讯作者：
L. Szalinski
中科院分区：
文献类型：
--
作者：
M. Banowski;D. Lucas;L. Szalinski
超快电子束 X 射线计算机断层扫描是在过去几年中开发的，旨在获取两相流的详细数据。在最近的一项研究中，我们在瞬态两相流测试设施 (TOPFLOW) 的垂直管道中研究了不同的气液流态。该研究包括对两相和不同流动方向具有不同表观速度的气液流动进行实验。所获得的数据是理解两相流现象的基础物理以及CFD代码的开发和验证所必需的。为了从重建的三维数据阵列中提取定量数据，由于现有分割算法的结果并不令人满意，因此开发了一种新的分割算法。这种新算法的独创性基于在缩小步骤中使用像素聚集逐步创建新气泡，而无需定义标记或起点。使用两种不同的气泡模型和真实的两相流测量将结果与阈值和梯度方法进行比较。新算法显示了最佳的定性和定量结果。
The ultrafast electron beam X-ray computed tomography was developed during the last years to obtain detailed data on two-phase flows. In a recent study we investigated different gas–liquid flow regimes in a vertical pipe at the Transient Two-phase Flow test facility (TOPFLOW). The study includes experiments on gas–liquid flows with varied superficial velocities for both phases and different flow directions. The obtained data is required for understanding fundamental physics of two-phase flow phenomena and for the development and validation of CFD codes.To extract quantitative data from the reconstructed three-dimensional data array, a new segmentation algorithm was developed, due the results of existing segmentation algorithms aren't satisfyingly. The originality of this new algorithm bases on a stepwise creation of new bubbles using pixel agglomeration in shrinking steps without defining markers or starting points. The results were compared with threshold and gradient methods using two different bubble phantoms and real two-phase flow measurements. The new algorithm shows the best qualitative and quantitative results.