The value of form factor k at different drafts is important in predicting full-scale total resistance and speed for different types of ships. In the ITTC community, most organizations predict form factor k using a low...The value of form factor k at different drafts is important in predicting full-scale total resistance and speed for different types of ships. In the ITTC community, most organizations predict form factor k using a low-speed model test. However, this method is problematic for ships with bulbous bows and transom. In this article, a Computational Fluid Dynamics(CFD)-based method is introduced to obtain k for different type of ships at different drafts, and a comparison is made between the CFD method and the model test. The results show that the CFD method produces reasonable k values. A grid generating method and turbulence model are briefly discussed in the context of obtaining a consistent k using CFD.展开更多
Different from the existing CFD-DEM models in which the ship remains stationary,a CFD-DEM model with the ship in forward motion is proposed in this paper to simulate the process of a ship sailing across pack ice area ...Different from the existing CFD-DEM models in which the ship remains stationary,a CFD-DEM model with the ship in forward motion is proposed in this paper to simulate the process of a ship sailing across pack ice area at a forward speed under different drafts.A high-precision method for generating pack ice area on the undisturbed free surface that can be used in conjunction with the proposed model is introduced.Taking an ice-strengthened Panamax bulker as study object,the available model test results are used to verify the reliability of the proposed model,which shows that the model can effectively evaluate the resistance performance and simulate the ship-ice-water interaction.Based on the verified model,the ice resistances on different parts of the hull are first investigated,which reveals that the ice resistance of the bow is most significant,while those of the midship and stern are negligible.Then,the speed dependence of ice resistance under different drafts is studied.It shows a strong nonlinearity under shallow draft,while the nonlinearity gradually weakens as the draft increases.Finally,the proportions of ice resistance and open-water resistance in the total resistance under different drafts and ship speeds are discussed.展开更多
基金Supported by Ministry of Industry and Information(No.K24097)
文摘The value of form factor k at different drafts is important in predicting full-scale total resistance and speed for different types of ships. In the ITTC community, most organizations predict form factor k using a low-speed model test. However, this method is problematic for ships with bulbous bows and transom. In this article, a Computational Fluid Dynamics(CFD)-based method is introduced to obtain k for different type of ships at different drafts, and a comparison is made between the CFD method and the model test. The results show that the CFD method produces reasonable k values. A grid generating method and turbulence model are briefly discussed in the context of obtaining a consistent k using CFD.
基金supported by the National Key Laboratory of Science and Technology on Hydrodynamics(Grant No.2022-JCJQ-LB-028).
文摘Different from the existing CFD-DEM models in which the ship remains stationary,a CFD-DEM model with the ship in forward motion is proposed in this paper to simulate the process of a ship sailing across pack ice area at a forward speed under different drafts.A high-precision method for generating pack ice area on the undisturbed free surface that can be used in conjunction with the proposed model is introduced.Taking an ice-strengthened Panamax bulker as study object,the available model test results are used to verify the reliability of the proposed model,which shows that the model can effectively evaluate the resistance performance and simulate the ship-ice-water interaction.Based on the verified model,the ice resistances on different parts of the hull are first investigated,which reveals that the ice resistance of the bow is most significant,while those of the midship and stern are negligible.Then,the speed dependence of ice resistance under different drafts is studied.It shows a strong nonlinearity under shallow draft,while the nonlinearity gradually weakens as the draft increases.Finally,the proportions of ice resistance and open-water resistance in the total resistance under different drafts and ship speeds are discussed.
