Numerical Simulation Of Ship Added Resistance In Waves Based On Numerical Wave Tank

The added resistance of waves will cause involuntary speed reduction of the ship.How to accurately forecast the added resistance has been a hot issue that people have paid attention to in the field of ship and marine engineering,and it is also necessary to design a ship with sound comprehensive navigation performance.Most of the traditional researches only focus on the added resistance and the hull movement of the ship in head seas.Actually a ship cannot always maintain in head seas.Therefore,it is of great significance to perform the research and forecast of added resistance under different wave direction angles.Based on the viscous flow theory and the free surface tracing technology VOF(volume of fluid)method,this paper establishes a numerical model of ship wave drag enhancement based on the continuous equation,N-S equations and ship motion equations of incompressible fluid.With the help of the software FINE / Marine,the drag enhancement characteristics of Wigley ship,a simplified ship model,are systematically studied.The main work and conclusions are as follows:(1)Based on the wave theory and the CFD software FINE/Marine,a three-dimensional numerical wave pool with wave-making and wave-reducing functions was established..The wave height meter is installed near the bow of the ship,and the obtained waveform time-history curve is compared with the theoretical value,which lays a foundation for the subsequent work.(2)The numerical simulation of the wave resistance increase of the Wigley ship model is carried out.The heave and pitch motion of the hull under different wavelengths are simulated.The numerical calculation results are in good contrast with the experimental values,which verifies the reliability and the reliability of the numerical method in this paper accuracy.(3)In regular waves,there is a certain change in the wave resistance increase of ships.With the increase of the wave direction angle,the added resistance gradually increases,and the added resistance reaches the maximum value at 60 °.And comparing the ratio of the total resistance of the plurality of wave angle to the waves at the drag Wigley ship.Studies have shown that wave resistance increase accounts for a large proportion of the total resistance.Even in transverse waves,added resistance accounts for more than 10% of total resistance.(4)Analyze the hull motion response and added resistance when the ship is navigating in the surf and irregular waves.When the ship is navigating in irregular waves,the effect of the wave angle on the ship’s pitching motion is not obvious,but it will have a greater impact on the heave and roll motion.When the wave direction angle reaches a certain angle,the ship may capsize due to too large rolling motion.In addition,the wave direction angle will also have a certain effect on the added resistance.The added resistance will increase as the wave direction angle increases.