Research On The Effect Of T-foil And Stern Flap On Deep-vee Ship's Anti-pitching

With the development and utilization of far-reaching sea resources and the development of marine rights and other development needs,the seaworthiness of existing ships and other operating platforms has been unable to meet the relevant requirements.While developing various high performance ships,how to improve the performance of high performance monohull ships is discussed.Among them,the deep-Vee line monohull ship has received widespread attention,because compared with the conventional round bilge ship,its sea-keeping,maneuverability,stability has greatly improved,compared with other high performance ships,its construction technology is relativity simple,and the scope of application is wide.How to further reduce the longitudinal motion of deep-Vee ship and improving the ship's sea-keeping in head sea is an important issue of general concern.There are many ways to improve ship wave resistance,including ship type optimization and the use of attachment technology.There has been a lot of research on ship anti-rolling,and get better anti-rolling effect,but the effective method of anti-pitching is still lacking.At present,the conventional ships' appendage contains T-foil,SSB,bow fin,tail fin,stern flap,and spoiler and so on.However,so far,the issue of ship anti-pitching reduction has not been well solved.In this paper,according to the characteristics of the deep-Vee ship,the anti-pitching reducing research of T-foil and stern flap was studied,the purpose is to explore ways and means that are easy to install,easy to implement,highly implementable and good anti-pitching reduction.Based on the theory of viscosity,using CFD(Computational Fluid Dynamics)technology and CFD software,this paper explores the numerical wave making method and verifies its effectiveness.The motion response numerical prediction method of the deep-Vee ship is verified.The numerical prediction method for the motion response of a deep-Vee ship with T-foil is studied,Study on hydrodynamic interaction between T-foil and hull;The effect of stern flap on the stress distribution and resistance of deep-Vee ship and the motion response in the wave are studied;the effect of different positions of T-foil on the forces and movements of the hull was studied;study on the influence of T-foil and stern flap combination on the force and wave motion response of deep-Vee ship.The research shows that the deep-Vee ship equipped with the stern flap will have a good drag reduction effect at medium and high speed,but the change of longitudinal motion performance of the deep-Vee ship is not very obvious;the longitudinal motion performance of the deep-Vee ship with T-foil and stern flap has been greatly improved.At the peak point of the longitudinal motion,the amplitude of heave motion,pitch motion and acceleration of center of gravity is significantly reduced,and the wave resistance increasing is also significantly reduced;changing T-foil attack angle also has a certain effect on the deep-Vee ship sea-keeping performance,select the appropriate T-foil attack angle will make deep-Vee ship sea-keeping performance further improved.