Investigation of developing two-phase Flow through complex geometries

两相流在工程应用和工业中有着广泛的应用。例如，蒸汽发生器、热交换器、制冷系统和油气混合物输送管道的设计需要详细的两相换热和压降分析。两相流具有复杂的性质，其特征是存在可变形的界面、湍流、相间相互作用和气相的可压缩性，这使得获得可靠的流动模型以及许多工业问题的可靠解决方案变得困难。当两相流经复杂的几何形状，如阀门、孔口、弯头和多相系统中常见的突然面积变化时，这些复杂性变得更加复杂。当两相流经彼此靠近的多个管道部件时，会产生额外的复杂性。在许多能源和油气输送系统中，由于各种退化机制，如流动加速腐蚀、空蚀、冲刷腐蚀和液体冲击侵蚀，在这种几何形状的发展中的两相流区会发生故障。这严重影响了这些系统的安全性和可靠性，有时还会导致人员伤亡和巨大的经济损失。这些失效模式强烈地依赖于传热和传质特性，而传热和传质特性受两相流重分布、相分离和流道几何形状内产生的流动不稳定性的影响。目前，在这些复杂的几何形状中发展两相流的情况还不完全清楚。因此，这项研究计划旨在了解复杂几何形状，特别是通过彼此接近的多个管道部件时，发展两相流动的基本行为。这项拟议研究的结果将导致开发可靠的机制模型和战略，以预测、监测或缓解相关的工业问题。这将大大增强多阶段系统的可持续性，并将直接惠及加拿大经济。此外，由于多相流领域的专业知识稀缺，为加拿大工业界和学术界提供具有独特专业知识的HQP是申请人研究计划背后的最终目标。

Two-phase flows are found in a wide range of engineering applications and industries. For example; the design of steam generators, heat exchanges, refrigeration systems, and pipelines for gas and oil mixtures transport requires detailed two-phase heat transfer and pressure drop analyses. The complex nature of the two-phase flow, which is characterized by the existence of the deformable interfaces, turbulence, phase interaction, and compressibility of the gas phase, makes it difficult to obtain reliable flow models and consequently reliable solutions for many industrial problems. These complexities are aggravated when the two-phase passes through complex geometries such as valves, orifices, elbows and sudden area change that commonly exists in the multiphase systems. Additional complexity arise when the two-phase passes through multiple piping components located close to each other. Failures in many energy and oil and gas transportation systems occur in the developing two-phase flow regions in such geometries due to variety of degradation mechanisms such as flow accelerated corrosion, cavitation erosion, erosion corrosion, and liquid impact erosion. This severely affects both safety and reliability of these systems and sometime leads to fatalities and huge economic loss. These failure modes found to strongly depend on both heat and mass transfer characteristics which are affected by the two-phase flow redistribution, phase separation and the flow instabilities generated within the geometry of the flow passage. Currently, developing two-phase flow in these complex geometries is not fully understood. Therefore, this research program aims at understanding the fundamental behaviour of developing two-phase flow through complex geometries, especially through multiple piping components with close proximity to one another. The outcomes of this proposed research will result in developing reliable mechanistic models and strategies to predict, monitor or mitigate pertinent industrial problems. This will significantly enhance the sustainability of multiphase systems and will directly benefit the Canadian economy. In addition, with the scarce expertise in the area of multiphase flow, the provision of HQPs, with such unique expertise to the Canadian industry and academia is the applicant’s ultimate objective behind his research program.