Experimental investigation on flow induced vibration excitation in the elastically mounted square cylinders

In this paper an experimental investigation is performed on a range of transverse gap ratios (0.5 <= T/D <= 4.5) between the cylinders arranged in side by side configuration. The pattern of the test cylinder motion, spectral diagram and amplitude are used to analyze the vibration excitation at different conditions such as free stream velocity, natural frequency of the test cylinder. From the results, for the spacing ratio of T/D = 0.5 it is observed that the cylinders gets excited beyond the critical velocity and vibrates in a spiral pattern with the line dominated spectrum, which implies that by having a similar frequency along with a phase shift, the characteristics behavior of the cylinder is observed to be like an oscillator with the cross wise and stream wise response. Besides that, it is also observed that the cylinders at higher spacing ratios (T/D = 4.5) producing minimum oscillation when compared to the smaller spacing ratios.