学术英语演讲

In 1969, Holland completed the first submerged SWATH of "Douglas", a displacement of 1200 tons, speed: 9 knots. In 1973, the United States built "Kama Lin", the small waterplane area test ship, a displacement of about 200 tons, can carry helicopters. * 模板来自于 / * 模板来自于 / * 模板来自于 / * 模板来自于 / * 模板来自于 / * 模板来自于 / * The hydrodynamic performance of the SWATH ship 二、The advantages and disadvantages of the SWATH ship 一、A brief history of the development of the SWATH ship 三、Researches on the speed of the SWATH ship 四、Relationships between ship form and performance of SWATH 五、Optimization and improvement of ship form of SWATH CONTENTS Small Water-Plane-Area Twin Hull 一、A brief history of the development of the SWATH ship The original catamaran(Sui and Tang dynasties) Douglas Kama Lin So far, more than 10 semi submersible swath ships have been built in the world, for hydrological investigation，marine engineering operations, fisheries or passenger transport,displacement:from 20 tons to 3000 tons, speed: 9 ~ 30 knots. 二、The advantages and disadvantages of the SWATH ship 1.Good calm water resistance and wave resistance performance 2.High propulsion efficiency 3.Good seakeeping performance 4.Larger deck area 5.Low cost and short period of construction Advantages 1.Greater frictional resistance 2.The larger radius of gyration at high speed 3.The layout of the ship main engine 4.Bad longitudinal stability at high speed 5.Draft and beam of SWATH are larger than those of the ship of same displacement Disadvantages 三、Researches on the speed of the SWATH ship Comparison of resistance performance of various ship forms Speed loss of various ship forms in waves 四、Relationships between ship form and performance of SWATH Rt=Rw+Rv+Rapp+Raw Among them： RW—wave resistance RV—viscous pressure resistance Rapp—appendage resistance Raw—added resistance in waves The total resistance formula: RW=RWB+RWS+2R