| When ships sailing in waves,the added resistance in wave tends to cause the speed lose problem,while the waves also bring about the ship motion and the green water issues.An effective forecast must be given for the added resistance,the ship motion,and the green water of the vessel in waves,etc.,to design transport vessels with excellent navigational performance and to ensure the navigate safety.In this paper,a three-dimensional numerical tank is established based on the CFD software package Fine/marine,and the grid convergence verification is carried out.The numerical simulation of the wave resistance of the three-dimensional floating body on the deck wave and the S175 container ship is carried out.On basis of this,the numerical calculation of the added resistance of the 14000TEU container ship in regular waves and irregular waves is carried out,and the wave profiles around the ship in different working conditions are monitored.Finally,the green water phenomenon of the vessel in regular and irregular waves is simulated.Pressure monitoring points are set at the bow,the wave board,the stern,etc.to monitor the force on the hull,and several wave gauges are set in the wave field to monitor the movement of the wave profile.Through the above work,the main conclusions are as follows:(1)The wave decay with time and the wave phase changes during the process of wave making using CFD software.The waves with good quality are obtained after the grid convergence verification test,the results lays a foundation for the subsequent simulation work.(2)In the test of the green water of a three-dimensional floating body and the verification of the added resistance of the S175 container ship,the numerical results agree well with the experimental data.These verify the accuracy of the present numerical method and the mesh scheme.(3)After carrying out the numerical simulation of the added resistance of the14000TEU container ship in the regular wave,the rule of the added resistance change versus the wave length is summarized.The higher the ship speed is,the farther the ship wave will transmit,and the larger the wave height will become,meanwhile the Kelvin wave group becomes more noticeable.When the incident wave length is approximately the ship length:λ/L_P _P=1.0,the heave motion of the ships change rapidly,and the added resistance coefficient is the largest.The added resistance coefficient tends to increase as the vessel speed increases.The motion responses converted using the RAO in regular waves agree well with those in the irregular wave obtained from the spectral analysis at the corresponding frequency.Finally,the added resistance coefficients of the ship in irregular wave of the simulations are made compared with those obtained from the linear superposition of the resistance coefficients in regular waves.The error between them is small when the vessel speed is low;however becomes larger when the vessel speed becomes higher.(4)Through the numerical simulation of the green water of the 14000TEU container ship in the regular wave,it is found that the sway and pitch motion of the hull has great influences on the water-on-deck phenomenon,and the incident wave height and the vessel speed are also influential.When the water-on-deck happens,the deck and the wave board of the vessel will suffer from the slamming pressure,however the pressure on the vessel stern will be relatively stable.The slamming pressure at the middle of the root of the wave board is the highest.In the irregular wave,the green water period becomes longer and irregular,the slamming pressure as well as the pressure on the stern both changes irregularly. |
