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January 2012 www.sname.org/sname/mt index, the probability of failure of the first component and the probability of ultimate failure of the whole hull girder must be eval- uated. e probability of failure is computed using a hybrid Latin Hypercube - second-order reliability method technique. e deter- ministic analyses during the simulations are conducted using an optimization approach for computing the ultimate bending strength of the whole hull girder and the progressive collapse method for computing the rst bending failure. Tacking Simulation of Sailing Yachts with New Model of Aerodynamic Force Variation During Tacking Maneuver BY YUTAKA MASUYAMA AND TOICHI FUKASAWA Published in the 2011 Journal of Sailboat Technology A mathematical model for the tacking maneuver of a sailing yacht is presented as an extension of research by the authors. e authors have proposed the equations of motion for the tacking maneu- ver expressed in the horizontal body axis system. e calculation method was applied to a 34-ft. sailing cruiser and the simulated result showed good agreement with the measured data from full- scale tests; however, the modeling of aerodynamic force variation during tacking was insu cient due to lack of information about the sail forces. In this report, the authors performed full-scale measurement of sail forces during tacking maneuvers using a sail dynamometer boat, Fujin , a 34-foot sailing cruiser with a measure- ment system to simultaneously obtain sail forces, sail shapes, and boat attitude. Based on the results of full-scale measurements, a new model of aerodynamic force variation for the tacking maneuver was proposed. e equations of motion were also simpli ed to more easily perform the numerical simulation. Using this calculation method, the tacking simulations were performed and compared with the measured data from three full-scale boats. e simulated results showed good agreement with the measured data. is simu- lation method provides an e ective means for assessment of tacking performance of general sailing yachts. Experimental Investigation of Sail Aerodynamic Behavior in Dynamic Conditions BY FABIO FOSSATI AND SARA MUGGIASCA Published in the 2011 Journal of Sailboat Technology e aerodynamic behavior of a 48-ft. yacht rig 3D scale model was characterized by means of wind tunnel tests. e experimental pro- gram, performed in the Politecnico di Milano Twisted Flow Wind Tunnel, allowed the aerodynamic forces to be characterized using forced motion tests and the aeroelastic behavior of the sail plan to be studied. Preliminary results are presented with reference to the typical encounter frequency range and typical pitch amplitudes cor- responding to best yacht velocity made good condition for di erent true wind speeds and related sea states. A new representation of the aeroelastic e ects is proposed in the form of aerodynamic hysteresis loops, obtained by plotting the sail plan aerodynamic coe cients against instantaneous apparent wind angle, varied using a har- monic law combining wind tunnel constant wind speed with sail plan center of e ort velocity induced by yacht pitch motion. A ?sail plan reduced velocity? concept is de ned, and experimental results show that this reduced velocity played a fundamental role in sail plan aerodynamics. Finally, an estimate of the aerodynamic added mass e ects is provided based on the comparison between the measured pitch moment during the ?wind o ? tests and the exper- imental test rig pitch moment of inertia. MTMaritime College THE S TATE U NIVERSITY N EW Y ORK ofABET Accreditation For All Five Engineering Programs - Marine Engineering- Mechanical Engineering- Electrical Engineering- Facilities Engineering- Naval Architecture Ranked by Payscale.com #1 in Mid-Career Median Salaries -Among State Universities #5 in Starting Median Salaries -Among Engineering Schools #5 in Mid-Career Median Salaries -Among Engineering Schools SUNY Maritime College Admissions: 718-409-7221www.sunymaritime.edu/admissions 54_C3_BDept_SNAME_Jan12_P4.indd 6112/22/11 3:45 PM