Study On Hydrodynamic Performance Of Large Lift T-foil Based On Vortex Generators

High-speed ships are faster than conventional ships,but their seaworthiness and stability are lacking.T-foil are widely used in the field of ship engineering because of their excellent anti-roll characteristics,although they have been widely used in the field of ship engineering,but the T-foil has also exposed some problems during its use: the lift generated during operation is much less than the recovery moment of the ship.This restricts the T-foil roll reduction effect.This thesis optimizes the design of conventional T-wings.Based on relevant studies,the generation of vortex of the airfoil suction surface can effectively increase the maximum lift,and the vortex generated by the T-wing in the process of active rotation is not sustainable and will greatly reduce the lift when the angular velocity of rotation is negative,or even lower than the lift of the wing in the static state.In this paper,the scheme of assembling vortex generators on the suction surface of the wing is proposed,and the vortex generator is used to generate a continuous and controllable suction surface vortex,the influence of vortex on the stall angle and maximum lift of the wing is studied,and a T-shaped wing with large lift is designed,which can provide greater lift for the hull than the conventional T-wing,reduce the wet area of the hull to reduce the resistance,and improve the seaworthiness of high-speed ships to a certain extent.This thesis uses the commercial CFD software STAR-CCM+ to calculate the influence of different installation positions of eddy current generator on the hydrodynamic performance of hydrofoils and obtain the motion law of suction surface vortex under different installation positions,so as to conduct hydrodynamic analysis of the whole airfoil,and design a large lift T-wing based on the vortex generator,the main research content is as follows:1.From the applicable point of view,foil model is established,model is established,and numerical simulation is carried out to calculate the rise,resistance coefficient and lift-drag ratio changes in the process of airfoil rotation.The vortex generators are installed on the basic foil,and the hydrodynamic performance of the foil is modeled and simulated at different angles.The lift and drag coefficients,lift-drag ratio and the motion of the eddy generated by the airfoil are studied.2.To study the influence of different parameters of the vortex generators on the hydrodynamic performance of the airfoil,including:(1)The influence of the distance between the vortex generators on the hydrodynamic performance of the overall foil;(2)The influence of the pitch of the vortex generators on the hydrodynamic performance of the overall foil;3.The vortex quality of the vortex generator under different parameters and the optimization effect of the hydrodynamic performance of the airfoil were analyzed,and the optimal installation parameters of the vortex generator on the wing surface were explored,and a high-lift T-foil based on the vortex generator was designed based on this,which was installed on a planing boat,and the overall numerical simulation of the hydrodynamic performance of the mother boat and the planing boat in the conventional T-foil/high-lift T-foil was carried out,and the forward and backward motion response of the planing boat was analyzed.It has been found that the vortex generator can inhibit the surface flow separation of the airfoil after the stall angle,thereby optimizing the hydrodynamic performance of the airfoil,and there are optimal installation parameters.Based on this design of the high-lift T-wing,through numerical simulation,the designed high-lift T-wing is applied to a high-speed taxiing boat,which can provide greater lift to reduce the wet area of the hull and effectively reduce drag,but the stability of the hull is reduced.