Flow Characteristic Analysis of Flow Induced Heat Exchanger Tube Vibration

A three-dimensional numerical model for heat transfer tube vibration induced by cross flow is proposed with two ways coupled approach. The characteristics of flow field are investigated based on the numerical model. The results show that, when Ur≤2, lift force coefficient increases as Ur increases, while drag force coefficient decreases first and then increases. When 2＜Ur＜9, the Locked In phenomenon occurs and drag force reaches the peak value prior to that of lift force. As Ur≥9, lift force is tending to zero. The drag force of flexible tube is about 2~2.5 times of that of the fixed tube, and the lift force is 6 times. Vibration makes the pressure distribution and wake vortex mode change. The transverse space between vortexes is amplified obviously compared to the case of fixed tube. There is only 2S mode existing in the present study.