Experiments and Computations for KCS Added Resistance for Variable Heading

2015 ◽  
Author(s):  
Hamid Sadat-Hosseini ◽  
Serge Toxopeus ◽  
Dong Hwan Kim ◽  
Teresa Castiglione ◽  
Yugo Sanada ◽  
...  
Keyword(s):  
Surface Profile ◽  
Engine Performance ◽  
Head Wave ◽  
Added Resistance ◽  
Local Flow ◽  
Wake Field ◽  
Head Waves ◽  
Calm Water ◽  
Free Surface Profile ◽  
Peak Location

Experiments, CFD and PF studies are performed for the KCS containership advancing at Froude number 0.26 in calm water and regular waves. The validation studies are conducted for variable wavelength and wave headings with wave slope of H/λ=1/60. CFD computations are conducted using two solvers CFDShip-Iowa and STAR-CCM+. PF studies are conducted using FATIMA. For CFD computations, calm water and head wave simulations are performed by towing the ship fixed in surge, sway, roll and yaw, but free to heave and pitch. For variable wave heading simulations, the roll motion is also free. For PF, the ship model moves at a given speed and the oscillations around 6DOF motions are computed for variable wave heading while the surge motion for head waves is restrained by adding a very large surge damping. For calm water, computations showed E<4%D for the resistance,<8%D for the sinkage, and <40%D for the trim. In head waves with variable wavelength, the errors for first harmonic variables for CFD and PF computations were small, <5%DR for amplitudes and <4%2π for phases. The errors for zeroth harmonics of motions and added resistance were large. For the added resistance, the largest error was for the peak location at λ/L=1.15 where the data also show large scatter. For variable wave heading at λ/L=1.0, the errors for first harmonic amplitudes were <17%DR for CFD and <26%DR for PF. The comparison errors for first harmonic phases were E<24%2π. The errors for the zeroth harmonic of motions and added resistance were again large. PF studies for variable wave headings were also conducted for more wavelength condition, showing good predictions for the heave and pitch motions for all cases while the surge and roll motions and added resistance were often not well predicted. Local flow studies were conducted for λ/L=1.37 to investigate the free surface profile and wake field predicted by CFD. The results showed a significant fluctuation in the wake field which can affect the propeller/engine performance. Additionally it was found that the average propeller inflow to the propeller is significantly higher in waves.

Head Wave Simulation of a KCS Model Using OpenFOAM for the Assessment of Sea-Margin

2021 ◽  
Author(s):  
Hafizul Islam ◽  
C. Guedes Soares
Keyword(s):  
Head Wave ◽  
Container Ship ◽  
Added Resistance ◽  
Free Condition ◽  
Wave Simulation ◽  
Calm Water ◽  
Sinkage And Trim ◽  
Simulation Results ◽  
Design Speed ◽  
Propulsion Power

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.

scholarly journals Full-Scale CFD Analysis of Double-M Craft Seakeeping Performance in Regular Head Waves

2021 ◽  
Vol 9 (5) ◽  
pp. 504
Author(s):  
Deniz Ozturk ◽  
Cihad Delen ◽  
Simone Mancini ◽  
Mehmet Ozan Serifoglu ◽  
Turgay Hizarci
Keyword(s):  
Full Scale ◽  
Stokes Wave ◽  
Added Resistance ◽  
Motion Responses ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Calm Water ◽  
Maximum Improvement ◽  
Fifth Order ◽  
Regular Head Waves

This study presents the full-scale resistance and seakeeping performance of an awarded Double-M craft designed as a 15 m next-generation Emergency Response and Rescue Vessel (ERRV). For this purpose, the Double-M craft is designed by comprising the benchmark Delft 372 catamaran with an additional center and two side hulls. First, the resistance and seakeeping analyses of Delft 372 catamaran are simulated on the model scale to verify and compare the numerical setup for Fr = 0.7. Second, the seakeeping performance of the full-scale Double-M craft is examined at Fr = 0.7 in regular head waves (λ/L = 1 to 2.5) for added resistance and 2-DOF motion responses. The turbulent flow is simulated by the unsteady RANS method with the Realizable Two-Layer k-ε scheme. The calm water is represented by the flat VOF (Volume of Fluid) wave, while the incident long waves are represented by the fifth-order Stokes wave. The residual resistance of the Double-M craft is improved by 2.45% compared to that of the Delft 372 catamaran. In the case of maximum improvement (at λ/L = 1.50), the relative added resistance of the Double-M craft is 10.34% lower than the Delft 372 catamaran; moreover, the heave and pitch motion responses were 72.5% and 35.5% less, respectively.

Study of Wave Added Resistance on Wigley Ship

2013 ◽  
Vol 468 ◽  
pp. 105-109
Author(s):  
Tao Sun ◽  
Ming Hui Yuan ◽  
Wei Wang ◽  
Nan Ye
Keyword(s):  
Total Resistance ◽  
Added Resistance ◽  
Ship Model ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Free Model ◽  
Calm Water ◽  
Significant Research ◽  
Energy Consuming ◽  
Hydrodynamic Potential

Global warming is becoming a serious problem nowadays. The emissions of greenhouse gas from vessels draw great attentions. As a significant research part of vessel seakeeping performance, resistance capability exert pretty effect on energy consuming. A Wigley ship model is set as the object to compute constraint and free model in calm water and head waves on resistance and hydrodynamic potential coefficients by STAR-CCM. Differences are discussed between both models. Effects on calculation of hydrostatic resistance ignoring trim and heave are revealed .Wave added resistance of free model is computed and compared at different amplitudes and wavelengths. How trim and heave matter the computed results are discussed. So does how wavelength and amplitudes influence total resistance is considered.

Disturbance Induced by a Pressure Distribution Moving Over a Free Surface

1970 ◽  
Vol 14 (03) ◽  
pp. 195-203
Author(s):  
T. T. Huang ◽  
K. K. Wong
Keyword(s):  
Free Surface ◽  
Pressure Distribution ◽  
Surface Effect ◽  
Surface Profile ◽  
Wave Theory ◽  
Local Flow ◽  
Closed Form Solutions ◽  
Pressure Trace ◽  
Surface Effect Ship ◽  
Free Surface Profile

This paper uses the linearized water-wave theory to analyze the disturbances induced by a constant pressure distribution with a rectangular planform moving over calm water. The methods developed, however, can be applied to other pressure distributions. Numerical schemes and computation results for typical speeds and beam/length ratios are presented for the pressure trace on the sea floor when the water depth is finite and the local flow pattern when the depth is infinite. For shallow waters, closed-form solutions for both the pressure trace and free-surface profile are obtained. A surface-effect ship acts like a moving pressure distribution as far as the induced disturbances in the water are concerned. Thus, the results of the present study may be useful for the design of surface-effect ships.

scholarly journals Evaluation of the Effect of Container Ship Characteristics on Added Resistance in Waves

2020 ◽  
Vol 8 (9) ◽  
pp. 696
Author(s):  
Ivana Martić ◽  
Nastia Degiuli ◽  
Andrea Farkas ◽  
Ivan Gospić
Keyword(s):  
Point Of View ◽  
Irregular Waves ◽  
Design Stage ◽  
Radius Of Gyration ◽  
Container Ship ◽  
Added Resistance ◽  
Head Waves ◽  
Calm Water ◽  
Added Resistance In Waves ◽  
Longitudinal Position

Added resistance in waves is one of the main causes of an increase in required power when a ship operates in actual service conditions. The assessment of added resistance in waves is important from both an economic and environmental point of view, owing to increasingly stringent rules set by the International Maritime Organization (IMO) with the aim to reduce CO2 emission by ships. For that reason, it is desirable to evaluate the added resistance in waves already in the preliminary ship design stage both in regular and irregular waves. Ships are traditionally designed and optimized with respect to calm water conditions. Within this research, the effect of prismatic coefficient, longitudinal position of the centre of buoyancy, trim, pitch radius of gyration, and ship speed on added resistance is investigated for the KCS (Kriso Container Ship) container ship in regular head waves and for different sea states. The calculations are performed using the 3D panel method based on Kelvin type Green function. The results for short waves are corrected to adequately take into account the diffraction component. The obtained results provide an insight into the effect of variation of ship characteristics on added resistance in waves.

Head Wave Simulation of a KCS Model Using OpenFOAM for the Assessment of Sea-Margin

2022 ◽  
pp. 1-24
Author(s):  
Hafizul Islam ◽  
Carlos Guedes Soares
Keyword(s):  
Head Wave ◽  
Container Ship ◽  
Added Resistance ◽  
Free Condition ◽  
Wave Simulation ◽  
Calm Water ◽  
Sinkage And Trim ◽  
Simulation Results ◽  
Design Speed ◽  
Propulsion Power

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

A Rankine Panel Method for Added Resistance of Ships in Waves

2012 ◽  
Author(s):  
Heinrich Söding ◽  
Vladimir Shigunov ◽  
Thomas E. Schellin ◽  
Ould el Moctar
Keyword(s):  
Degrees Of Freedom ◽  
Periodic Wave ◽  
Panel Method ◽  
Ship Motions ◽  
Added Resistance ◽  
Rankine Panel Method ◽  
Head Waves ◽  
Calm Water ◽  
Wigley Hull ◽  
The Time Domain

A new Rankine panel method and an extended RANS solver were employed to predict added resistance in head waves at different Froude numbers of a Wigley hull, a large tanker, and a modern containership. The frequency domain panel method, using Rankine sources as basic flow potentials, accounts for the interaction of the linear periodic wave-induced flow with the nonlinear steady flow caused by the ship’s forward speed in calm water, including nonlinear free surface conditions and dynamic squat. Added resistance in waves is obtained by pressure integration method. The time domain RANS solver, based on a finite volume method, is extended to solve the nonlinear equations of the rigid body six-degrees-of-freedom ship motions. The favorable comparison of panel and RANS predictions demonstrated that the Rankine method is suitable to efficiently obtain reliable predictions of added resistance of ships in waves. Comparable model test predictions correlated less favorably although overall agreement was felt to be acceptable, considering the difficulties associated with procedures to obtain accurate measurements.

Study of Wave Added Resistance and Motions of KCS in Waves With Different Wave Lengths

2019 ◽  
Author(s):  
Hao Guo ◽  
Decheng Wan
Keyword(s):  
Navier Stokes ◽  
Head Wave ◽  
Ship Motions ◽  
Added Resistance ◽  
Head Waves ◽  
Wide Range ◽  
Stokes Waves ◽  
The Relationship ◽  
Nonlinear Behaviors ◽  
Regular Head Waves

Abstract Estimating added resistance and motions of a ship in waves are essential to predict fuel consumption and speed loss. The added resistance and motions of the 3600 TEU KRISO container ship (KCS) in regular head waves under different wavelengths are investigated using Reynolds-Averaged Navier-Stokes (RANS) method. Volume of Fluid (VOF) method is applied to capture the free surface. The in-house computational fluid dynamics solver, naoe-FOAM-SJTU, is used to compute the added resistance and motions of KCS in regular head waves. Firstly, the first-order Stokes waves in deep water are adopted and generated in naoe-FOAM-SJTU as a numerical wave tank. Secondly, it is presented that the KCS with a Froude number of 0.261 advances in these waves. Regular wave conditions with a wide range of wavelength (0.65 < λ/L < 1.95) are considered. The variations of resistance, pitch and heave show good agreement with experimental results. To investigate nonlinear behaviors of predicted results, Fast Fourier Transform (FFT) is applied to analyze the results of resistance, heave and pitch with in head wave (μ = 180°). KCS with and without motions is also compared to investigate the relationship between components of resistance and wavelengths. The results of added resistances show that the added resistance of KCS is mainly induced by ship diffraction in short waves. The wave diffraction is not affected by wave frequency. In addition, CFD can accurately calculate the problem on added resistance and ship motions.

The Effect of Bow Steepness and Flare on the Resistance of Sailing Yachts in Calm Water and Waves

2001 ◽  
Author(s):  
J. A. Keuning ◽  
R. Onnink ◽  
A. Damman
Keyword(s):  
Water Resistance ◽  
Added Resistance ◽  
University Of Technology ◽  
Head Waves ◽  
Master Thesis ◽  
Calm Water ◽  
Added Resistance In Waves ◽  
Bow Flare ◽  
Sailing Yacht ◽  
Resistance Performance

In this paper some results are presented of two studies carried out at the Ship hydromechanics Department of the Delft University of Technology: one, on the influence of an increase of stem steepness of a sailing yacht, and another, which was largely carried out by T.J.E. Tincelin as part of his master thesis at Delft University of Technology, on the effect of above waterline bow flare are presented. To investigate the influence of bow steepness a model of the Delft Systematic Yacht Hull Series (DSYHS) has been used as a parent model of a new small subseries with two additional derivatives each with increased bow steepness. The influence on both the calm water resistance and the added resistance in head waves has been investigated. To investigate the influence of bow flare, two models of a typical "Open 60" design have been used: one "normal" and one with almost no flare in the bowsections. These have been tested in calm water and in both head- and following­waves to investigate the effects of this difference in bow shape on the calm water resistance, on added resistance in waves, and on the relative motions at the bow. The results are presented and some comparisons with calculations made. Also some general conclusions with respect to resistance, performance and safety are drawn.

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