Experimental Assessment on the mitigation of Vortex-Induced Vibrations with elastomeric blankets.

Flexible structures such as subsea pipelines are subjected to vortex-induced vibration (VIV) in free-span conditions. For depth and ultra-depth waters, the VIV suppression for such structures can be an alternative to avoid precocious replacement and maintenance. Intending to contribute to this matter, this work develops a preliminary assessment of the mitigation of VIV with elastomeric blankets through experiments in a flume channel of the Laboratory of Waves and Current (LOC-COPPE-UFRJ). This assessment is based on several tests with a fixed model subject to a uniform incoming flow at the subcritical range. Three different elastomeric materials were considered in this investigation, and several configurations in length and thickness were evaluated. For the main parameters of comparison, the drag (Cd) and lift (Cl) coefficients, the results indicate a good performance of short and less flexible blankets, reaching up to 58% and 88% for Cd and Cl, respectively.