In-Situ and Temporary Augmentation of Ship Hull Forms to Improve Top Speed

The U.S. Navy is looking for drag reduction technologies for sealift ships to enhance their operating characteristics. Particularly, there is the request for a technology that allows 8000NM non-refueling range at the speed higher than 25 knots for a 91 meter length 15 meter beam ship and 2500NM for a 40 knots 137 meter length ship. MECHMATH LLC suggests top speed improvement for these ships by combination of a special hull design and friction reduction by ventilated air cavities. The Phase II work also includes: Development of a stern seal for the cavity; Development of an algorithm and computer codes for the active flow control system assigned to keep the drag reduction in wavy seas; Optimization of ventilation rate with use of experiments in a water tunnel with built in special wavemaker; Towing tests of the ventilated ship model in calm and wavy condition; The extrapolation of towing tank data to full-scale conditions; Analysis of applicability of drag reduction by cavitation for ship length of 200 meter plus in the speed range from 30 to 40 knots. Phase II Option will be assigned to study of the combined effect of joining ships in train and drag reduction by cavitation.