Analysis Of Ship Resistance And Flow Field In Shallow Water

With the development of economic globalization,large ships have been more widely applied,influence of water depth for ships in coastal and sailing in shallow water is also becoming increasingly obvious,so the hydrodynamic performance of shallow water ship is a topic worth studying.Usually hydrodynamic analysis of ship in shallow water is based on test in towing tank,which requires large amounts of time and cost,however using the CFD method can save a lot of cost,and more information could be extracted for analysis.This paper selects DTMB 5415 and KCS ship model as the mainly model.Comparing two ships in the hydrodynamic properties of different depths conditions change,then analyzing for shallow water conditions on the two ships in the calculation results were compared at different scales.Firstly,hydrodynamic performance performed in deep water ship model is predicted.Three different unstructured mesh method is tried for the KCS ship's stern section,then compared with the experimental data in towing tank,a best meshing method is selected;for boat DTMB 5415,VOF model is used on ship wave simulation,compared with experimental results and the results of foreign scholars.Then the depth conditions is changed to explore how different depths for the ship impact on the hydrodynamic performance.For KCS mainly some characteristic is compared,like the resistance coefficient,the z direction of the suction force,the propeller disk wake field and flow field below the ship stern.For DTMB 5415 model the wave and the change of the flow under the ship are compared.Finally,it's considered that the scale for model ship influences the hydrodynamic performance in shallow-water.Three scales are selected to investigate scale effect for KCS and DTMB 5415.In the process,the effects of Reynolds number for the shape factor is mainly verified by analysis.The flow field around the ship under different scales and the change of the surface pressure hull are also considered.