COMPUTATIONAL ANALYSIS OF TWIN-SKIN CLOTH SAILS FOR HIGH-PERFORMANCE SAILING VESSELS

Current efforts to reduce carbon emissions have brought a resurgence of interest in sail design. Sails could be used to supplement conventional propulsion on cargo vessels or even be used on future energy ships. Energy ships are conceptual vessels that would roam the oceans harvesting energy using hydroelectric turbines and the power developed by sails. To further the estimates of energy ship power production, a towable drag device was designed and built to provide data about the effect of a hydro-electric turbine’s drag on a vessel’s speed. In addition, computational fluid dynamics studies were conducted on a new twin-skin sail design to determine its potential for use on energy-ships. This twin skin sail differs from traditional sails by using two cloth elements to create an airfoil-like section with finite thickness. Both fluid-structure interaction and typical static simulations were performed. Findings show that the twin-skin mainsail aerodynamically outperforms all but two-element rigid sails. In addition, twin-skin mainsails have the ability to be reefed or completely taken down, making them more manageable in extreme weather. This performance in addition to its ease of handling makes it a good fit for use on an energy-ship. Future work should be done to analyze this design in three-dimensional flows as well as the effects of mounting multiple sails on a single vessel.Ensign, United States NavyApproved for public release. Distribution is unlimited