Numerical Analysis of Added Resistance on Ship in Parametric Roll Motions

2016 ◽  
Author(s):  
Jae-Hoon Lee ◽  
Yonghwan Kim ◽  
Min-Guk Seo
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Field Method ◽  
Roll Motion ◽  
Added Resistance ◽  
Regular Waves ◽  
Nonlinear Formulation ◽  
Parametric Roll ◽  
Weakly Nonlinear ◽  
Rankine Panel Method

In the present study, the added resistance of a containership in parametric roll motion is investigated. The numerical simulation is carried out using a three dimensional Rankine panel method along with the weakly nonlinear formulation. The added resistance is evaluated by a near-field method, namely, the direct integration of the 2nd-order pressure on a body surface. To calculate the component resulting from the large-amplitude roll motion, the higher-order restoring and Froude-Krylov forces on wetted hull surfaces are taken into account. With or without parametric roll in regular waves, the components of added resistance classified with respect to integral terms are compared to figure out the important of each term. Through the investigation, the correlation between the added resistance and parametric roll is derived from coupling and decoupling the components of roll motion and vertical motions.

A Non-Linear Numerical Method for the Simulation of Parametric Roll Resonance in Regular Waves

2008 ◽  
Author(s):  
T. M. Ahmed ◽  
E. J. Ballard ◽  
D. A. Hudson ◽  
P. Temarel
Keyword(s):  
Numerical Method ◽  
Potential Flow ◽  
Degrees Of Freedom ◽  
Linear Time ◽  
Three Dimensional ◽  
Regular Waves ◽  
Time Step ◽  
Parametric Roll ◽  
Non Linear ◽  
Parametric Roll Resonance

In this paper, a non-linear time-domain method is used for the prediction of parametric roll resonance in regular waves, assuming the ship to be a system with three degrees of freedom in heave, pitch and roll. Coupled heave and pitch motions are obtained using a three-dimensional frequency-domain potential flow method which also provides the requisite hydrodynamic data of the ship in roll i.e. the potential flow based added inertia and damping. Periodic changes in the underwater hull geometry due to heave, pitch and the wave profile are calculated as a function of the instantaneous breadth. This is carried out using a two-dimensional approach i.e. for sections along the ship and at each time step. This formulation leads to a mathematical model that represents the roll equation of motion with third order non-linearities in the parametric excitation terms. Non-linearities in the roll damping and restoring terms are also accounted for. This method has been applied to two different hull forms, a post-Panamax C11 class containership and a transom stern Trawler, both travelling in regular waves. Special attention is focused on the influence of different operational aspects on parametric roll. Obtained results demonstrate that this numerical method succeeds in producing results similar to those available in the literature, both numerical and experimental.

Numerical Study of the Added Resistance of Ship Advancing in Waves Using Far-Field and Near-Field Methods

2015 ◽  
Author(s):  
D. C. Hong ◽  
J. G. Kim ◽  
K. H. Song ◽  
H. K. Lee
Keyword(s):  
Numerical Solutions ◽  
Near Field ◽  
Three Dimensional ◽  
Design Stage ◽  
Linear Potential ◽  
Far Field ◽  
Forward Speed ◽  
Added Resistance ◽  
Economic Point ◽  
Wave Range

When a ship advances in a seaway, it undergoes 6-degree-of-freedom motion. The ship motions and wave loads are very important from operability and survivability points of view. The resistance increase due to waves is also important from the economic point of view. Although the accurate prediction of these seakeeping characteristics should be done using the unsteady CFD computations, the analytical method based on the linear potential flow theory have been widely used to evaluate them at the early design stage since the latter does not require large computing resources. In the present paper, the added resistance of a ship advancing in waves was calculated using both Maruo’s far-field formula and the near-field method. The radiation-diffraction potential over the wetted surface of the ship has been obtained using the three-dimensional frequency-domain forward-speed free-surface Green function (Brard 1948) and the forward-speed Green integral equation (Hong 2000). Numerical solutions are obtained by making use of the 9-node second-order inner collocation boundary element method (Hong et al. 2014b). In the present paper, Maruo’s far-field formula was combined with the exact three-dimensional Kochin function so that the added resistance thereby obtained could show good comparison with experimental results over the entire wave range including the short wave range. The near-field added resistance is the time mean value of the 2nd-order forces acting on the advancing ship in waves. The time-mean hydrodynamic force, obtained by using direct integration of the hydrodynamic pressure due to the sum of the unsteady potential and steady potential approximated by the double-body potential over the wetted surface of the ship, was also presented. Comparison of the present far-field and simplified near-field numerical values and the experimental values reported by Journee (1992) of the added resistance for the Wigley ship models I and II has been made in order to find appropriate numerical values of the far-field added resistance over the entire frequency range of interest.

Numerical Study on Added Resistance Computations in Short Waves

2016 ◽  
Author(s):  
Xinshu Zhang ◽  
Kang Tian ◽  
Yunxiang You
Keyword(s):  
Experimental Data ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Three Dimensional ◽  
Added Resistance ◽  
Rankine Panel Method ◽  
Short Waves ◽  
Global Performance ◽  
Different Types ◽  
Wigley Hull

Evaluation of added resistance in short waves is critical to the assessment of the global performance of a ship traveling in a seaway. In this paper, three methods of added resistance evaluation in short waves are briefly reviewed, including those proposed by Fujii & Takahashi [1], Faltinsen et al. [2], and Kuroda et al. [3]. Based on the experimental data collected by Kuroda et al., a new method is developed for the estimation of added resistance in short waves. The proposed method is validated by comparing the obtained numerical results with experimental data and other numerical solutions for different types of hulls, including the Wigley hull I, KVLCC2 hull, Series 60 hull with CB = 0.7, and the S-175 hull. The present study confirms that the developed method can well predict the added resistance in short waves and complement the three-dimensional Rankine panel method developed in a previous study focusing on intermediate and long waves.

Far-field drag decomposition using hybrid formulas and vorticity based area sensors

2020 ◽  
pp. 095441002097390
Author(s):  
L Qiao ◽  
XL He ◽  
Y Sun ◽  
JQ Bai ◽  
L Li
Keyword(s):  
Flow Field ◽  
Axial Velocity ◽  
Near Field ◽  
Three Dimensional ◽  
Field Method ◽  
Wave Drag ◽  
Viscous Drag ◽  
Far Field ◽  
Velocity Defect ◽  
Detection Failure

Numerical simulation of flow-field has become an indispensable tool for aerodynamic design. Usually, wall surface integration is a tool used to calculate values of pressure drag and skin friction drag, but the aerodynamic mechanism of drag production is still confusing. In present work, in order to decompose the total drag into viscous drag, wave drag, induced drag, and spurious drag, a far-field drag decomposition (FDD) method is developed. This method depends on axial velocity defect and area sensor functions. The present work proposes three hybrid formulas for velocity defect to tackle the negative square root issue by analyzing the existing axial velocity defect formulas. For dealing with the issue of detection failure for near-wall cells, a novel vorticity based viscous area sensor function is proposed. The new area sensor function is also independent of the turbulence model, which ensures easy application to general simulation methods for flow-field. Three tests cases are there to validate the proposed FDD method. The three dimensional transonic CRM test case shows that the present improvement is crucial for accurate drag decomposition. Excellent agreement between total decomposed drags and results from the near-field method or experimental data further confirms the correctness.

Study on added resistance of a ship under parametric roll motion

2017 ◽  
Vol 144 ◽  
pp. 1-13 ◽  
Author(s):  
Jae-Hoon Lee ◽  
Yonghwan Kim
Keyword(s):  
Roll Motion ◽  
Added Resistance ◽  
Parametric Roll

scholarly journals Numerical and Analytical Approaches for Roll Motion Analysis in Regular Longitudinal Waves

2015 ◽  
Vol 22 (3) ◽  
pp. 28-35
Author(s):  
Emre Peşman ◽  
Deniz Can Kolukısa ◽  
Metin Taylan
Keyword(s):  
Motion Analysis ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Roll Motion ◽  
Diffraction Radiation ◽  
Parametric Roll ◽  
Stability And Bifurcations ◽  
Flow Theories ◽  
Analytical Approaches ◽  
Numerical Approaches

Abstract In this study numerical and analytical approaches were investigated in terms of accuracy of their results, practicality of solution and ability to reproduce the main features of the parametric roll phenomenon such as loss of stability and bifurcations in parametric roll motion analysis of ships. In general, single-degree-of-freedom analytical approach is based on reducing number of degrees of freedom from 3 to 1 by using the quasi-static Froude-Krylov assumption, incorporating heave and pitch effects by means of a time varying restoring moment. On the other hand, numerical approaches to motion of six and four degrees of freedom are based on three dimensional diffraction/radiation and potential flow theories. In summary, this paper reveals that analytical approaches are sufficiently adequate to obtain accurate practical results for this relatively complex phenomenon.

A Study on the Added Resistance Performance of Catamarans in Waves

2018 ◽  
Author(s):  
Emanuela Ageno ◽  
Luca Bonfiglio ◽  
Dario Bruzzone ◽  
Giuliano Vernengo ◽  
Diego Villa
Keyword(s):  
Near Field ◽  
Field Method ◽  
Longitudinal Component ◽  
Added Resistance ◽  
Systematic Analysis ◽  
First Order ◽  
Heading Angle ◽  
The Mean ◽  
State Force ◽  
Resistance Performance

The added resistance of a catamaran advancing in waves is investigated in the framework of a non-viscous potential theory. A linear Boundary Element Method (BEM) is used for the first order seakeeping prediction and the mean longitudinal component of the second-order steady-state force is computed by using a near-field method. Both methods are briefly presented and preliminary validations on both a mono-hull and a catamaran are shown. A systematic analysis of the added resistance of the so-called DUT catamaran is presented highlighting the effects of the advancing speed and those of the ship-wave heading angle.

Parametric Roll of High Speed Ships in Regular Waves

2013 ◽  
Author(s):  
Hisham Moideen ◽  
Abhilash Somayajula ◽  
Jeffrey M. Falzarano
Keyword(s):  
Time Domain ◽  
High Speed ◽  
Mathieu Equation ◽  
Analytical Models ◽  
Roll Motion ◽  
Regular Waves ◽  
Parametric Roll ◽  
Hull Form ◽  
Linear Damping ◽  
Metacentric Height

Analysis of ship parametric roll has generally been restricted to simple analytical models and sophisticated time domain simulations. Simple analytical models do not capture all the critical dynamics while time-domain simulations are often time consuming to implement. The model presented in this paper captures the essential dynamics of the system without over simplification. This work incorporates various important aspects of the system and assesses the significance of including or ignoring these aspects. Special consideration is given to the fact that a hull form asymmetric about the design waterline would not lead to a perfectly harmonic variation in metacentric height. Many of the previous works on parametric roll make the assumption of linearized and harmonic behavior of the time-varying restoring arm or metacentric height. This assumption enables modeling the roll motion as a Mathieu equation. This paper provides a critical assessment of this assumption and suggests modeling the roll motion as a Hills equation. Also the effects of non-linear damping are included to evaluate its effect on the bounded parametric roll amplitude in a simplified manner.

Time Domain Prediction of Added Resistance of Ships

2011 ◽  
Vol 55 (03) ◽  
pp. 163-184 ◽  
Author(s):  
Fuat Kara
Keyword(s):  
Time Domain ◽  
Near Field ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Field Method ◽  
Floating Body ◽  
Impulse Response Functions ◽  
Added Resistance ◽  
Transient Wave ◽  
First Order

The prediction of the added resistance of the ships that can be computed from quadratic product of the first-order quantities is presented using the near-field method based on the direct pressure integration over floating body in time domain. The transient wave-body interaction of the first-order radiation and diffraction problems are solved as the impulsive velocity of the floating body by the use of a three dimensional panel method with Neumann-Kelvin method. These radiation and diffraction forces are the input for the solution of the equation of the motion that is solved by the use of the time marching scheme. The exact initial-boundary-value problem is linearized about a uniform flow, and recast as an integral equation using the transient free-surface Green function. A Wigley III hull form with forward speed is used for the numerical prediction of the different parameters. The calculated mean second-order added resistance and unsteady first-order impulse-response functions, hydrodynamics coefficients, exciting forces, and response amplitude operators are compared with experimental results.

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