Abstract Pipe two-phase flow non-invasive imaging is of great interest in the field of industry. In particular, small bubble flow imaging through opaque pipes is challenging. Ultrasound computed tomography can be a relevant technique for this purpose. However, perturbation phenomena that are inherent to the configuration (acoustic impedance mismatching, circumferential propagation, reverberation) limit two aspects: the performance of the technique and the use of conventional inversion algorithms. The objectives of the presented work are: (i) to predict the effects of the pipe wall on ultrasonic waves for both metallic and plastic pipe, (ii) to define a consistent inversion algorithm taking into account those effects, (iii) to validate and to assess the limitations of the designed imaging numerical tool using an experimental setup. The benchmark configuration consists of 150 mm diameter 3 mm thick pipes containing 6 mm diameter rods acting as reference scatterers. Two materials of very different acoustical properties were tested: aluminum and PMMA. The results highlighted that the quality of the reconstructed image is very dependent on the pipe material. The results showed that, using an adapted inversion model, consistent target reconstruction is obtained. Based on numerical predictions, performance limitations are reached for metallic pipes.

中文翻译：

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使用超声计算机断层扫描的管道两相流非侵入性成像：二维数值和实验性能评估

摘要 管道两相流无创成像在工业领域备受关注。特别是，通过不透明管道的小气泡流成像具有挑战性。超声计算机断层扫描可以是用于此目的的相关技术。然而，配置固有的扰动现象（声阻抗失配、圆周传播、混响）限制了两个方面：技术的性能和传统反演算法的使用。本工作的目标是：(i) 预测管壁对金属和塑料管道的超声波的影响，(ii) 定义考虑这些影响的一致反演算法，(iii) 验证和使用实验装置评估设计的成像数值工具的局限性。基准配置由 150 毫米直径 3 毫米厚的管道组成，其中包含 6 毫米直径的杆作为参考散射体。测试了两种声学特性截然不同的材料：铝和 PMMA。结果强调，重建图像的质量在很大程度上取决于管道材料。结果表明，使用自适应反演模型，可以获得一致的目标重建。根据数值预测，金属管道达到了性能限制。使用自适应反演模型，可以获得一致的目标重建。根据数值预测，金属管道达到了性能限制。使用适应的反演模型，获得一致的目标重建。根据数值预测，金属管道达到了性能限制。