Particle image velocimetry in single and multiphase flow

这项研究将促进我们对气液两相流基本现象的理解。 这些流动发生在许多工业过程中，其中液体和蒸汽同时在管道中流动。 例如石油和天然气设施、锅炉、蒸汽发生器、冷凝器、再热器、蒸馏塔和核反应堆堆芯。 在这项工作中感兴趣的主要流动状态是弹状流和环状流。 段塞流的特征是由细长气泡（称为泰勒气泡）分离的液体段塞。 环形流由在管壁上流动的液体和沿管中心向下流动的蒸汽组成。 了解这些流动对于正确设计设备并从而最大限度地减少涉及两相流的过程的能耗非常重要。 这项工作的具体目的是在这些流的速度场的基本测量。 当试图提高这些应用中设备的性能时，这种类型的信息是非常有价值的。 例如，速度场是最终决定液体与管壁传热效率的量。 它还决定了泵送混合物通过管道所需的功率。

This research will advance our understanding of fundamental phenomena in two-phase, gas-liquid flows. These flows occur in many industrial processes where both a liquid and a vapour flow in a pipe at the same time. Examples are oil and gas facilities, boilers, steam generators, condensers, reheaters, distillation columns, and nuclear reactor cores. The primary flow regimes of interest in this work are slug flow and annular flow. Slug flow is characterised by slugs of liquid separated by elongated bubbles (called Taylor bubbles). Annular flow consists of liquid flowing on the pipe wall and a vapour flowing down the centre of the pipe. An understanding of these flows is important to allow this equipment to be properly designed and thereby minimise the energy consumption of processes involving two-phase flow. This work specifically aims to make fundamental measurements of the velocity field in these flows. This type of information is extremely valuable when attempting to improve the performance of equipment in these applications. For example, the velocity field is the quantity that ultimately determines how effectively a liquid transfers heat with a tube wall. It also determines the power required to pump the mixture through the pipe.