Vortex induced motion of the cylinder is suppressed by wearing a closed membrane

TL;DR

This study introduces a novel method using a closed membrane to significantly suppress vortex-induced motion of cylinders in fluid, reducing motion amplitude by up to 85% in key flow conditions.

Contribution

The paper presents a new VIM suppression technique with experimental validation showing high effectiveness in reducing cylinder motion and drag.

Findings

VIM is effectively suppressed by the membrane in the lock-in region.

Cylinder motion amplitude is reduced by up to 85%.

In-line mean drag force decreases with the membrane.

Abstract

Vortex-induced motion (VIM) of cylindrical structures in fluid is a common occurrence in nature and engineering. Over the years, numerous techniques for suppressing VIM have been developed. In this study, we propose a novel method for VIM suppression by applying a closed membrane to the cylinder. A demonstration experiment was conducted in a circulation water channel, varying the reduced velocity (U*) from 2 to 11. The results demonstrate that the closed membrane effectively suppresses VIM, particularly in the lock-in region of U* from 5 to 9, where the motion amplitude of the cylinder is reduced by up to 85%. Additionally, the in-line mean drag force is also reduced when compared to that of a bare cylinder. It is important to note that this study is preliminary. However, the evidence obtained thus far is highly significant.