Theoretical and Experimental Study on Flow-Induced Vibration of an Overflow Pipe Due to Discharged Fluid Flow

Abstract

This paper deals with an experimental study and a theoretical stability analysis on unstable vibration of an overflow pipe due to discharged fluid flow. In the system, the overflow pipe consists of vertical and horizontal pipes and an elbow, which is attached at the bottom of the vertical pipe, and the discharged fluid falls along the inner surface of the vertical pipe and changes the flow direction at the elbow. First, the vibration characteristics and instability region of the unstable vibration are examined by the experiments. The instability region in which the unstable vibration occurs is examined with changing flow rate, vertical pipe length and inlet shape of the overflow pipe. Next, the theoretical stability analysis is conducted. In the theoretical analysis, a theoretical model of the unstable vibration in the vertical direction is developed, and the instability region is shown by the stability analysis.