scholarly journals Numerical and Experimental Study of Resistance, Sinkage and Trim of a Container Ship

2017 ◽  
Vol 194 ◽  
pp. 67-73 ◽  
Author(s):  
G.K. Saha ◽  
M.A. Miazee
2021 ◽  
Author(s):  
Hafizul Islam ◽  
C. Guedes Soares

Abstract The paper presents calm water and head wave simulation results for a KRISO Container Ship (KCS) model. All simulations have been performed using the open source CFD toolkit, OpenFOAM. Initially, a systematic verification study has been performed using the ITTC guideline to assess the simulation associated uncertainties. After that, a validation study has been performed to assess the accuracy of the results. Next, calm water simulations have been performed with sinkage and trim free condition at varying speeds. Later, head wave simulations have been performed with heave and pitch free motion. Simulations were repeated for varying wave lengths to assess the encountered added resistance by the ship in design speed. The results have been validated against available experimental data. Finally, power predictions have been made for both calm water and head wave cases to assess the required propulsion power. The paper tries to assess the validity of using 25% addition as sea margin over calm water prediction to consider wave encounters.


2015 ◽  
Vol 18 (4) ◽  
pp. 136-144
Author(s):  
Quang Le ◽  
Huong Thi Thanh Pham ◽  
He Van Ngo

The acticle presents a method for minimizing energy exploitation of the ship through reducing ship resistances. Ship resistances include water resistances caused by frictions of water and waves acting on hull part in the water and air resistance acting on the hull part above water surface. To reduce the resistance caused by water friction, the authors proposed a method which intervene directly on the boundary layer of ship hull by the creating a gas injection foaming layer. To reduce air resistance, the authors used CFD method to optimaze arrangement of container on deck for a container ship. Obtained results showed that the proposed method help to save 5-8% of the consuming energy.


Author(s):  
Yi Liu ◽  
Lu Zou ◽  
Zao-Jian Zou

Understanding the manoeuvring performance of a ship requires accurate predictions of the hydrodynamic forces and moments on the ship. In the present study, the hydrodynamic forces and moments on a manoeuvring container ship at various rudder and drift angles are numerically predicted by solving the unsteady Reynolds-averaged Navier–Stokes equations. The effects of dynamic sinkage and trim on the hydrodynamic forces are first investigated together with a grid dependency study to estimate the numerical error and uncertainty caused by grid discretization, and with a validation study combining the experimental data. The results show that the effect of dynamic sinkage and trim is non-negligible, since including it improves the hydrodynamic force predictions and reduces the numerical error and uncertainty, and the averaged error and uncertainty are smaller than the other computational fluid dynamics results where sinkage and trim were fixed with given values from model tests. Therefore, it is included in the subsequent systematic simulations regarding the influence of rudder and drift angles. The computed forces, moments and rudder coefficients at different rudder and drift angles on the container ship are compared with the benchmark model test data. From the computations, all the predicted quantities are in satisfactory agreement with the experimental data. The details of the flow filed and hydrodynamic forces, such as pressure distributions, transverse force distributions along the hull, velocity contours, streamlines and wave patterns are presented and discussed, and a deep insight into the physical mechanism in the hydrodynamic forces on a manoeuvring ship is obtained.


Author(s):  
Hafizul Islam ◽  
Carlos Guedes Soares

Abstract The paper presents calm water and head wave simulation results for a KRISO Container Ship (KCS) model. All simulations have been performed using the open source CFD toolkit, OpenFOAM. Initially, a systematic verification study is presented using the ITTC guideline to assess the simulation associated uncertainties. After that, a validation study is performed to assess the accuracy of the results. Next, calm water simulations are performed with sinkage and trim free condition at varying speeds. Later, head wave simulations are performed with heave and pitch free motion. Simulations are repeated for varying wave lengths to assess the encountered added resistance by the ship in design speed. The results are validated against available experimental data. Finally, power predictions are made for both calm water and head wave cases to assess the required propulsion power. The paper tries to assess the validity of using 25% addition as sea margin over calm water prediction to consider wave encounters


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