Ride control method of wave-piercing catamaran with T-foil and flaps

A T-foil is installed at the bow and two flaps are installed at the stern transom to control the motion of a wave-piercing catamaran. The T-foil and flaps are controlled by a ride controller, so as to smoothen pitch and heave motions of the ship effectively. Firstly, the mathematical model to describe the ship´s vertical motion is constructed, and its coefficients are established from the Strip Theory. Then, the hydrodynamic characteristics of the T-foil and transom flaps are analyzed by employing CFD methods. A ride control system adopting LQG optimum control theory is designed and motions of a catamaran in different sea states are analyzed. The results show that it is feasible and effective to reduce pitch and heave motions by using the LQG controller.