The Effect of Coverage Length and Density on the Performance of Fairings

Abstract

While the application of fairings can both increase a tubular’s fatigue life and decrease a tubular’s drag, it is not always possible or economical to fully cover a tubular with fairings. Aside from the desire to minimize the cost of VIV suppression by only covering the necessary portion of a tubular’s span, the presence of connectors, anodes, and other appurtenances can restrict the ability to install fairings over the entire tubular’s length. The result is that it is critical to understand how much of a tubular’s span should be covered with fairings and the effect of partial coverage on the overall suppression performance, and drag reduction, of the fairings system. This paper utilizes data from a two similar test programs to examine the effects of coverage length and density on the performance of fairings. The results show that the location of the fairings has a substantial effect on both the local and global response of the tubular. In practical terms, having fairings present in the high current region can suppress VIV in both the high current and low current regions of the tubular.