Experimental Investigation on VIV of the Flexible Model Under Full Scale Re Number

In this paper, VIV of a flexible model within full scale Re number regime are studied. The experiments were carried out in the towing tank by towing the flexible model with a constant forward speed. The bending stiffness of the flexible model was specially designed and controlled by a steel core pipe, whose diameter and wall thickness were selected according to the structural naturally frequency, vortex-shedding frequency and strength requirements under VIV conditions. The cylindrical rubber was bundled onto the core pipe to increase the diameter of the pipe to the full scale riser’s diameter, so that the model has the full scale hydrodynamic diameter, and therefore the full scale Re number. The strain information in both IL and CF directions of the model was measured by the optical fiber strain gages. The data was analyzed by the modal super position method. The VIV characters at both IL and CF directions under full scale Re number were studied.Copyright © 2011 by ASME