scholarly journals An Approach to Determine Optimal Bow Configuration of Polar Ships under Combined Ice and Calm-Water Conditions

2021 ◽  
Vol 9 (6) ◽  
pp. 680
Author(s):  
Hui Li ◽  
Yan Feng ◽  
Muk Chen Ong ◽  
Xin Zhao ◽  
Li Zhou
Keyword(s):  
Numerical Simulation ◽  
Water Resistance ◽  
Numerical Technique ◽  
Experimental Studies ◽  
Resistance Index ◽  
Simulation Method ◽  
Present Approach ◽  
Calm Water ◽  
Level Ice ◽  
Ice Resistance

Selecting an optimal bow configuration is critical to the preliminary design of polar ships. This paper proposes an approach to determine the optimal bow of polar ships based on present numerical simulation and available published experimental studies. Unlike conventional methods, the present approach integrates both ice resistance and calm-water resistance with the navigating time. A numerical simulation method of an icebreaking vessel going straight ahead in level ice is developed using SPH (smoothed particle hydrodynamics) numerical technique of LS-DYNA. The present numerical results for the ice resistance in level ice are in satisfactory agreement with the available published experimental data. The bow configurations with superior icebreaking capability are obtained by analyzing the sensitivities due to the buttock angle γ, the frame angle β and the waterline angle α. The calm-water resistance is calculated using FVM (finite volume method). Finally, an overall resistance index devised from the ship resistance in ice/water weighted by their corresponding weighted navigation time is proposed. The present approach can be used for evaluating the integrated resistance performance of the polar ships operating in both a water route and ice route.

scholarly journals Numerical Simulation of a Polar Ship Moving in Level Ice Based on a One-Way Coupling Method

2020 ◽  
Vol 8 (9) ◽  
pp. 692
Author(s):  
Bao-Yu Ni ◽  
Zi-Wang Chen ◽  
Kai Zhong ◽  
Xin-Ang Li ◽  
Yan-Zhuo Xue
Keyword(s):  
Numerical Simulation ◽  
Failure Process ◽  
Coupling Method ◽  
Crack Propagation Process ◽  
Order Of Magnitude ◽  
Level Ice ◽  
Ice Failure ◽  
Ice Resistance ◽  
Ship Speed ◽  
Good Agreement

In most previous ice–ship interaction studies involving fluid effects, ice was taken as unbreakable. Building breakable level ice on water domain is still a big challenge in numerical simulation. This paper overcomes this difficulty and presents a numerical modeling of a ship moving in level ice on the water by using a one-way CFD-DEM (computational fluid dynamics-discrete element method) coupling method. The detailed numerical processes and techniques are introduced. The ice crack propagation process including radial and circular cracks have been observed. Numerical results are compared with previous experimental data and good agreement has been achieved. The results show that water resistance is an order of magnitude smaller than ice resistance during the ice-breaking process. Ice resistance shows strong oscillation along with ice failure process, which are affected by ship speed and ice thickness significantly.

Numerical Simulation of Dynamic Response of Planing Craft Sailing in Calm Water

2014 ◽  
Vol 590 ◽  
pp. 37-41
Author(s):  
Yu Min Su ◽  
Yun Hui Li ◽  
Hai Long Shen
Keyword(s):  
Numerical Simulation ◽  
Empirical Formula ◽  
High Speed ◽  
Evaluation Method ◽  
Simulation Method ◽  
Experimental Results ◽  
Planing Craft ◽  
Calm Water ◽  
Performance Evaluation Method ◽  
Good Agreement

In order to forecast the sailing response of planing craft at high speed rapidly and accurately, CFD code Fine/Marine solver was used to calculate the resistance and sailing attitude of a high-speed planing craft, then the numerical results were compared with experimental results and empirical formula results. The results showed that resistance error calculated by Fine/Marine was between 5% and 10%, trim and heave results were in good agreement with experimental results, and had greater accuracy compared with the empirical formula results. The feasibility of this numerical simulation method was validated and this method provided an effect performance evaluation method for new designing planing crafts.

Numerical Simulation of Moored Ship in Level Ice

2011 ◽  
Author(s):  
Li Zhou ◽  
Biao Su ◽  
Kaj Riska ◽  
Torgeir Moan
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Relative Motion ◽  
Parameter Sensitivity ◽  
Two Dimensional ◽  
Ice Drift ◽  
Sensitivity Studies ◽  
Level Ice ◽  
Ice Forces ◽  
Ice Resistance

The dynamic ice forces on a moored icebreaking tanker induced by drifting level ice were simulated with a two dimensional numerical model. Based on a heading controller which aimed to keep the hull head towards the drifting ice, ice resistance on ship was mainly estimated when taking the relative motion between the hull and ice into account. The mooring force and responses of the moored vessel were also looked into through parameter sensitivity studies with different ice thicknesses and ice drift speeds.

Numerical Simulation Method for Damaged Ships Under Flooding Condition

2013 ◽  
Author(s):  
Hirotada Hashimoto ◽  
Kouki Kawamura ◽  
Makoto Sueyoshi
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Mps Method ◽  
Strip Method ◽  
Numerical Simulation Method ◽  
Damage Stability ◽  
Calm Water ◽  
Good Potential ◽  
Moving Particle ◽  
Method Model

Securing the survivability under flooding condition is one of the most important subjects in ship design. For realizing advanced assessment of damage stability, a numerical simulation method for damaged ships is developed by combining the moving particle semi-implicit method (MPS method) and the ordinary strip method based on potential flow theory. In this method, the flow field around the damaged hull including damaged compartments is solved by the MPS method and that around the intact hull is done by the strip method, separately. In order to validate the proposed method, model experiments are conducted for a damaged pure car and truck carrier in calm water and regular beam waves. Then numerical results of the ship motion and the flooding into the damaged compartment are compared with them. As a result, it is demonstrated that the proposed method has good potential for the prediction of dynamic behaviours of damaged ships under flooding condition.

Full Scale Measurement on Level Ice Resistance of Icebreaker

2011 ◽  
Author(s):  
Abdillah Suyuthi ◽  
Bernt J. Leira ◽  
Kaj Riska
Keyword(s):  
Water Resistance ◽  
Open Water ◽  
Full Scale ◽  
Ice Thickness ◽  
Total Resistance ◽  
Conservation Of Energy ◽  
Ship Resistance ◽  
Level Ice ◽  
Ice Resistance ◽  
Ship Speed

This paper presents results from the investigation of ship resistance on first year level ice in the Barent Sea. The basis for the work is the availability of full scale measurement data obtained on board of KV Svalbard in 2007. Measurements were made of the ice thickness, ship speed over ground in addition to setting power. The ice thickness was measured by means of an electromagnetic device, which enables careful selection of the time sequences for which level ice is present. By utilizing Newton II law and conservation of energy, the total resistance can be determined. The ice resistance in level ice was then obtained by subtracting the open-water resistance from the total resistance. The open-water resistance was measured when the ship was traveling in open water during the expedition. The relationship between the ship resistance and the ship speed over ground in level ice was finally obtained and compared with the Lindqvist formulation of estimation of ice resistance.

Model Calm Water Resistance and Motion – Simulations, Experiments and Verification

2017 ◽  
Author(s):  
Renan Santana Pelícia ◽  
João Lucas Dozzi Dantas
Keyword(s):  
Water Resistance ◽  
Mesh Size ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Multiphase Model ◽  
Computational Fluid Dynamics Simulation ◽  
Towing Tank ◽  
Calm Water ◽  
Sinkage And Trim ◽  
The Impact

To assess the impact of each bow design on motion and drag, two platform supply vessel models (PSV) of same parallel middle body and stern were tested in deep water regime on the Towing Tank of the Institute for Technological Research of the State of São Paulo (IPT). Calm water resistance was measured for different operating condition (draft and speed). One of the models was also tested in waves. Moreover, the same Towing Tank tests conditions were re-created in Computational Fluid Dynamics simulation and the results of resistance, sinkage and trim were compared to appraise the reliability of the simulation method. Seeking a competitive performance compared to Towing Tank tests, the simulations’ mesh size was kept below 5 million cells and executed on the software STAR-CCM+ using a multiphase model (VOF) and the K-Omega turbulence model. As expected, the desired performance was achieved while providing consistent outcomes as most cases reached resistance errors below 5%, with better adherence at lower speeds.

scholarly journals Numerical Simulation of Resistance Field of Hull-Propeller-Rudder Coupling

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Hong Xie ◽  
Baoji Zhang
Keyword(s):  
Numerical Simulation ◽  
Body Force ◽  
Water Resistance ◽  
Wave Resistance ◽  
The Body ◽  
System Model ◽  
Force Method ◽  
Body Force Method ◽  
Calm Water ◽  
Calculation Results

Based on the incompressible RANS equation, the KVLCC1 ship's resistance field's numerical simulation is carried out. In this paper, the bare hull (calm water resistance and wave resistance) and hull-propeller-rudder models are studied and compared with the values of the Hydrostatic resistance test. In the hull-propeller-rudder system's performance analysis, the body force method is used to replace the real propeller model. The new calculation domain is set for the hull-propeller-rudder system model and meshed again to obtain the highly reliable numerical simulation results. Finally, the calculation results are analyzed. The research results in this paper can provide technical support for the resistance of similar ship types.

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