A STUDY ON SEMI-SUBMERSIBLE HIGH SPEED SHIP WITH WINGS (2ND REPORT) - STABILITY CONTROL BY MAIN AND TAIL WING FLAPS

Stability control by flaps of a semi-submersible displacement-type high-speed ship with wings was studied. The vehicle, called HSV (High-speed Semi-submersible Vehicle with wings) consists of a main hull, main and tail wings with flaps, and a strut to support the super-structure. The HSV floats at a certain draft like a conventional ship while it is still, and it submerges when it moves forward due to a downward lift force induced by the main wings. HSV does not have as much upright moment as conventional ships because of its small waterplane area. HSV may be stabilised by active control of flaps. Experiments were carried out to study the possibility of stability control by the flaps of the main and tail wings. An automatic control system was developed under which HSV is towed with the heaving, rolling, pitching and yawing motions free. The angles of attack of the flaps were controlled after the measured ship motion, in order to stabilise the motion. It is concluded, that although the control is not perfect due to the mechanical limitation of the used system. HSV can run stably by the active control of the flaps. The experiments among regular waves made clear that waves would not be a serious factor for the stability of HSV. See also abstract no 91122879.