Calderon A.,Transonic Hull Company Inc. |
Hedd L.,Oceanic Consulting Corporation |
Hedd L.,Oceanic Consulting Corporation Labrador
11th International Conference on Fast Sea Transportation, FAST 2011 - Proceedings | Year: 2011
A theoretical study of potential seakeeping problems and improvement opportunities of Transonic Hull (TH) was followed by a seakeeping investigation using powered models, small manned boats, and tow tank experiments. An equation defining weight/resistance ratio of a planing surface in two-dimensional inviscid flow verified the low values of all planing hulls, compared to displacement hulls. The TH shape was developed to have resistance characteristics similar to that of a planing hull but with a significant decrease in motion and slamming at speed. Experiments confirmed the TH's design features improved stability in pitch and yaw in waves, and maintained a nearzero pitch attitude at all speeds and wave conditions. Manned boat trials indicated very low acceleration levels in heave, surge, pitch, yaw, and roll; good directional and lateral stability and control allowed ease in crossing and overtaking waves. Tow tank experiments were conducted to directly compare the performance of a conventional fast crew boat and a TH based-vessel within similar design requirements. Experiments in irregular waves indicated vertical acceleration at the cabin of the baseline vessel in 2-meter waves at 50 knots was more than twice the acceleration at 20 knots. Transonic's cabin vertical acceleration at 50 knots was only 60% of its 20 knot value. Transonic's vertical accelerations at 50 knots had 70% reduction compared to the baseline vessel in the same irregular sea conditions. © 2011 American Society of Naval Engineers.