A Study on the Flow Induced Vibration of a Tube Array by a Two-phase Flow : 2nd Report, Large Amplitude Vibration by Steam-Water Flow

Abstract

The large amplitude vibration caused by high-speed steam-water two-phase flow is reported. A similar phenomenon for conditions of almost atmospheric pressure and room temperature is mentioned in the first report. This second report shows the test results operated under conditions of up to 5.8 Pa and up to 270°C, and the analytical approach based on the balance of energy. Small size test tube bundles tuned to the adequated low frequency are excited by steam-water two-phase cross flow. The water velocity is increased step by step while the steam velocity is kept constant. The criteria of unstable oscillation caused by steam-water two-phase flow is proposed as being as likely as that of the air-water two-phase flow.