Theoretical Analysis on the Operation Performance of Air Cushion Vehicle

The amphibious Air Cushion Vehicle(ACV) is lifted by air cushion,and propelled forward over the ground,the water and the paludal zone.It is very different from the general ship,carriage and airplane in the operation.Roll will be induced as the air is leaked from one side of shipboard when ACV is turning,and great slideangle will be brought since the less resistance between the ACV and air cushion.ACV is easy to turn down at high speed and sideslip and could be in dangerous state when operated improperly.Threfore,the operation performance is very important to the development of ACV.In this paper,the researches on the steering maneuverability are performed as the ACV being lift on the air,and many steering trials are carried out,such as turning test steered with air rudder or air propeller pitch difference,returning straight test and Z maneuvering test when the ACV simulated by the simulation system with six degrees of freedom is on the straight steering and is controlled by headkeeping control system.Firstly,the model with six degrees of freedom including an ACV and air rudder and air propeller mathematical model is given in this paper.Then,on calm occasion,the circle gyration characteristic is obtained when the ACV is steered by different rudder angle and propeller pitch difference.Thirdly,on windiness occasion,screw gyration characteristic and whirligig gyration characteristic under strong wind are also obtained when the ACV is steered by different rudder angle and propeller pitch difference.Finally,returning straight characteristic with much more different from conventional ship is got.The operation performances obtained in this paper possess very important signification in practice and theory for the ACV coordinate control researchers and operators.