DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD SHIP PERFORMANCE DEPT
This program evaluated the cambered-hull effect on resistance and propulsion for a small waterplane area twin hull SWATH IV. This experimental evaluation was divided into six sections to investigate the affects of variations in draft, propeller diameter, correlation allowance, one propeller driving - one windmilling, change of hull camber from inboard to outboard, and in experimental techniques using free to trim and heave, free to heave and captive modes. The effects of draft on resistance and propulsion are sizeable in the low speed range, but are not significant above a speed length ratio of 1.0. The propulsion coefficients are not significantly changed by correlation allowance. Hull camber inward was superior for both resistance and propulsion. The powering characteristics of Model 5287 was dependent on interference, sinkage and trim effects. The technique for conducting the experiments consequently is of prime importance.