ABSTRACT

ABSTRACT: Transient flow is the intermediate stage flow when the flow conditions are changed from one steady state to another, caused by the sudden changes in the operating conditions, such as abrupt closure or opening of the control valve and starting or stopping of pumps. In liquid-filled pipe systems, such disturbances create pressure waves of large magnitude which travel to and fro. The propagation and reflection of these pressure waves is referred to as hydraulic transients or ‘water hammer’, which can either rise or drop the normal working pressure of the pipe system. Cavitation (which is the formation, growth and collapse of vapor bubbles in a flowing liquid) can result in a region when the pressure of the liquid drops below its vapor pressure. Pipe systems also experience severe dynamic forces during transient flow due to fluid structure interaction. Fluid induced structural motion, structure induced fluid motion, and the underlying coupling mechanisms, are commonly referred to as Fluid Structure Interaction (FSI). This study aims to review a sample of the relevant literature on the main related topics, such as water hammer, cavitation, FSI and viscoelasticity.

1 INTRODUCTION