Session: 09-01-11 Wind Energy: Cables 1

Paper Number: 126678

126678 - Vortex Induced Vibrations of a Lazy Wave Dynamic Power Cable Under Varying Currents and Propagation Directions: Analysis of Strain 

Vortex induced vibrations (VIV) on a flexible dynamic power cable in lazy wave configuration was investigated experimentally to understand its behaviour under currents of varying magnitude. The preliminary study investigates the effect of increasing current magnitudes in the range 0.1-0.8 m/s and for three different current propagation directions (i.e. 0, 90 and 180 degrees to the cable position) on a scaled model power cable of external diameter 0.031 m. The experiments were undertaken at the FloWave combined wave-current facility of The University of Edinburgh.  The tests falls in the subcritical range with Reynolds number varying from 10³ to 10⁴.  The cable was instrumented with water-proofed IP68 strain gauges at seven locations along the cable length at 0.5 m intervals and total bending strain at each point location was measured. The cable was also instrumented with load cells to measure six components loads and moments, and point displacements at a large number of locations, however these are not presented in this paper.

In this paper, the bending strain and the corresponding response spectra at seven locations along the length of the cable are presented. The impact of VIV on the measured strain and how it affects the response frequencies (hence the Strouhal number) and with change in the magnitude of currents and propagation directions are illustrated.  The results indicated that the strain magnitude and response frequencies are influenced by the currents. The detailed analysis of the data collected, results and discussions will be presented in the full paper.

Presenting Author: Rameeza Moideen The University of Edinburgh

Presenting Author Biography: Rameeza Moideen is a research associate at University of Edinburgh. Her main area of interest is fluid structure interaction studies focused on offshore Renewable energy. She is currently working on vortex-induced vibrations on dynamic power cables.

Authors:

Rameeza Moideen The University of Edinburgh
Venki Venugopal The University of Edinburgh
John Chaplin University of Southampton