Flow visualization around cylinders in a channel flow using particle image velocimetry

One of the major concerns with power plant steam generators is tube vibration caused by turbulent flow buffeting. The vibration can cause wear of the tubes at the tube supports and at tube joints that eventually leads to leaks and rupture. When the cumulative leaks affect the steam generator performance, the plant is shut down and the leaking tubes are either repaired or plugged. Not only is the repair procedure very costly in terms of the repair costs themselves and loss of income due to the plant outage, but it is also costly in the sense that the steam generator design has been altered or has been totally replaced. This normally leads to more repairs in the future. To better understand this behavior of turbulent flow buffeting (the cause of many tube problems), it was felt that quantitative experimental data is needed to test the empirical correlations that predict the behavior of turbulent flow around cylinders. Perhaps this quantitative data could lead to a better understanding of this particular fluid behavior and motion and this understanding would hopefully then lead to design solutions that can be implemented to avoid the problem. (author)