Experimental Investigation of Vortex-Induced Vibration on an Inclined Circular Cylinder

This paper presents experimental results of vortex-induced oscillations of an inclined circular cylinder mounted on an elastic base. Models are mounted on an air-bearing elastic base, instrumented with strain gages, accelerometers and a load cell. The experiments were carried out on a water channel facility at NDF-EPUSP. The elastic base has low structural damping and is free to oscillate only in the cross-flow direction. The cylinder axis is inclined in relation to the current. New measurements on the dynamic response oscillations of this inclined cylinder, due to vortex-induced vibrations (VIV), are compared with previous experiments on a vertical cylinder. VIV is investigated by conducting experiments in two ways: first, the cylinder is maintained vertical on the elastic base, with a uniform current normal to its axis, and the response curve is obtained; subsequently, the investigation is carried out changing the angle of inclination from 0 to 45 degrees in relation to vertical. The results for a vertical cylinder are in accordance with other literature measurements for mass ratio m*=2. For the inclined model, using the decomposition of the flow on the direction normal to cylinder axis, the results for amplitude, drag and lift coefficients are consistent with the vertical cylinder.