Tests have been performed on two equal diameter cylinders with low mass ratio in tandem subjected to uniform flows in a towing tank at subcritical Reynolds numbers. Qualisys video motion capture system was used to measure VIV and spring bars were used instead of commonly used parallel linkage mechanism for this kind of test. Two circular cylinders of 100 mm in diameter and 1.5 m in length were towed vertically at constant speeds through the towing tank to simulate uniform current condition. Some key VIV parameters such as amplitude over diameter, lift and drag coefficients are presented against a non dimensional parameter known as reduced velocity to understand the effect of one risers motion to another. It was found that the downstream cylinder motion was influenced by the phase difference between upstream and downstream cylinders along with the displacement of upstream cylinder. Results of this study can be used as validation materials for CFD analysis that is very important to design riser system for oil and gas industry, also mentioned experiment procedure can be treated as a guide for future endeavor to perform similar kind of tests.
M. Mobassher Tofa, Adi Maimun, Yasser M. Ahmed, Saeed Jamei, Saman Kader and Hassan Abyn, 2014. Vortex Induced Vibration on Two Equal Diameter Cylinders with Low Mass Ratio in Tandem. Journal of Applied Sciences, 14: 3578-3584.