Numerical Prediction of Wave Patterns Due to Motion of 3D Bodies by Kelvin-Havelock Sources

AbstractThis paper discusses the numerical evaluation of the hydrodynamic characteristics of submerged and surface piercing moving bodies. Generally, two main classes of potential methods are used for hydrodynamic characteristic analysis of steady moving bodies which are Rankine and Kelvin-Havelock singularity distribution. In this paper, the Kelvin- Havelock sources are used for simulating the moving bodies and then free surface wave patterns are obtained. Numerical evaluation of potential distribution of a Kelvin-Havelock source is completely presented and discussed. Numerical results are calculated and presented for a 2D cylinder, single source, two parallel moving source, sphere, ellipsoid and standard Wigley hull in different situation that show acceptable agreement with results of other literatures or experiments.

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Construction and performance analysis of data warehouse based on ship propulsion system

E3S Web of Conferences ◽

10.1051/e3sconf/202124801060 ◽

2021 ◽

Vol 248 ◽

pp. 01060

Author(s):

Qi Hu ◽

Yutao Chen ◽

Yuqian He

Keyword(s):

Data Warehouse ◽

Visual Analysis ◽

Hydrodynamic Characteristic ◽

Propulsion System ◽

Multidimensional Analysis ◽

Hydrodynamic Characteristics ◽

Soft Sensing ◽

Ship Propulsion ◽

System Data ◽

And Performance

A large number of operation data will be generated in the process of ship propulsion system operation. Aiming at the processing, analysis and application of these operation data, a data warehouse for propulsion system is constructed based on the operation data of a ship, and the multidimensional analysis and result display of data are realized by combining OLAP technology with visual analysis software tableau. On the basis of the data warehouse, the soft sensing of parameters is applied to the data warehouse. Based on the soft sensing data, the hydrodynamic characteristics of the propeller are studied, and the hydrodynamic characteristic curves of the propeller are obtained. The research of ship propulsion system based on data warehouse provides support for the comprehensive information of propulsion system data.

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Application of Ecological Vegetation for a Shipping Hub

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.488-489.322 ◽

2014 ◽

Vol 488-489 ◽

pp. 322-328

Author(s):

Chun Xin Zhong ◽

Shi Yao Xiao ◽

Jin Long Liu ◽

Wei Zhang

Keyword(s):

Hydrodynamic Characteristic ◽

Water Levels ◽

Hydrodynamic Characteristics ◽

Protection Zone ◽

Protection Area ◽

Landscape Zone ◽

Vegetation Selection

Hydrodynamic characteristic is an important reference to select vegetation material of ecological revetment engineering. In this paper, embankment will be divided into bottom-protection zone, key-protection zone, hydrophilic zone, landscape zone according to hydrodynamic characteristics of different water levels. Vegetations adapting to different protection area analyzed and discussed. With the example of ecological revetment in Naji reservoir in Guangxi, China, vegetation selection on different protection zone is demonstrated.

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Numerical Hull Resistance and Hydrodynamic Characteristics of an Independently Rotating Multi-Hull Vessel

Volume 9: Rodney Eatock Taylor Honoring Symposium on Marine and Offshore Hydrodynamics; Takeshi Kinoshita Honoring Symposium on Offshore Technology ◽

10.1115/omae2019-95403 ◽

2019 ◽

Cited By ~ 1

Author(s):

Sharath Srinivasamurthy ◽

Hiroshi Sakamoto ◽

Tatsuo Nishikawa ◽

Yasunori Nihei

Keyword(s):

Numerical Simulation ◽

Pressure Distribution ◽

Cfd Simulation ◽

Hydrodynamic Characteristics ◽

Cfd Simulations ◽

Basic Framework ◽

Wave Patterns ◽

Experimental Findings ◽

Hydrodynamic Effects ◽

Simulation Scheme

Abstract In this study, an attempt is made to understand the hydrodynamic characteristics of an automated multi-hull vessel named as Quadmaran. Firstly, a single hull of the Quadmaran vessel is considered and numerical CFD simulation is performed using OpenFOAM. Hull resistance predictions are compared with the experimental findings and numerical simulation is validated. After validating the simulation scheme, further CFD simulations are performed on two hulls with varying distance between them to understand the hydrodynamic characteristics of different configurations. Pressure distribution and wave patterns around the hulls are also summarized and discussed in the paper. Further, efforts are made to optimize the distance between the hulls for reducing hull resistance. A basic framework is suggested to carefully consider the hydrodynamic effects for multi-hull vessels.

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Research on hydrodynamic characteristics of cylinder planing

Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University ◽

10.1051/jnwpu/20213910101 ◽

2021 ◽

Vol 39 (1) ◽

pp. 101-110

Author(s):

Fuqiang Liu ◽

Kai Luo ◽

Hongge Liang ◽

Chuang Huang ◽

Shaohang Geng ◽

...

Keyword(s):

Numerical Simulation ◽

Drag Coefficient ◽

High Speed ◽

Lift Coefficient ◽

Hydrodynamic Characteristic ◽

Calculation Model ◽

Simulation Software ◽

Hydrodynamic Characteristics ◽

Water Splash ◽

Flow Field Characteristics

This paper selects SST k-w turbulence model and VOF wave to construct a numerical calculation model of moving body planning on a flat free surface based on STAR-CCM+ numerical simulation software. The construction model is checked through foreign classic literature, and the numerical simulation results are in good agreement with the experimental results. The hydrodynamic numerical errors are less than 5%, which is within the engineering error range. The model can be used for the numerical simulation of the planning cylinder. In this paper, it is used to simulate the planing process of cylinder with different speeds and different submerged depths, and the flow field characteristics and hydrodynamic characteristics in the planing process are obtained. The results show that waves appear at the tail and the tail liquid splashes to form a water splash during the planing process of the cylinder on a flat surface. The higher the speed of the planning cylinder is, and the deeper the submersion depth, the more pronounced waves at the tail. When the cylinder has a Fr number Cv≥8, the hydrodynamic force of the cylinder is almost unchanged, and it is not affected by the speed. But when Cv=3, the hydrodynamic characteristic coefficient is higher. The drag coefficient is 20% higher than that in the high-speed (Cv≥8) planing process. The lift coefficient is 3 times of high-speed planing lift coefficient. It is related to the surface pressure and frictional force distribution of cylinder during the low-speed planing. There is a linear relationship between the drag coefficient and the submerged depth during the cylinder planing at different submerged depths.

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Hydrodynamic Characteristics Change of the Pearl River Delta Channel Network in the Recent 50 Years

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.573-574.415 ◽

2012 ◽

Vol 573-574 ◽

pp. 415-420

Author(s):

Chao Tan ◽

Ben Sheng Huang ◽

Qing Shu Yang ◽

Jing Qiu

Keyword(s):

Pearl River Delta ◽

Hydrodynamic Characteristic ◽

River Delta ◽

Pearl River ◽

Hydrodynamic Characteristics ◽

Main Stream ◽

Channel Network ◽

The Pearl River Delta ◽

The 1950S ◽

The Pearl River

The Pearl River delta channel network in the 1950s and 1990s is modeled and validated, and the hydrodynamic characteristic is analyzed during flood and drought at the same time. The study result shows that the model well simulates the real situation, which can be used for hydrodynamic characteristics analysis; There were obvious split ratio changes in the main branch in the late 50 years, the change degree of node in North River and near by is greater than West River’s. The waterlevel line of the West River main stream in the 1990s is generally lower than in the 1950s, especially the upstream of West River is more dramatic decline. River terrain changes caused by intensive human activities is the main reason why hydrodynamic force of the Pearl River Delta channel network district changed for the past 50 years.

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A NUMERICAL EVALUATION OF THE THERMAL AND HYDRODYNAMIC CHARACTERISTICS OF LAMINAR CELLULAR CONVECTION BETWEEN RIGID HORIZONTAL SURFACES

10.1615/ihtc4.3480 ◽

1970 ◽

Cited By ~ 1

Author(s):

J. L. Wantland

Keyword(s):

Numerical Evaluation ◽

Hydrodynamic Characteristics

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A Numerical Calculation of Hydrodynamic Forces on a Seagoing Ship by 3-D Source Technique With Forward Speed

23rd International Conference on Offshore Mechanics and Arctic Engineering, Volume 1, Parts A and B ◽

10.1115/omae2004-51565 ◽

2004 ◽

Cited By ~ 1

Author(s):

Yoshiyiki Inoue ◽

Md. Kamruzzaman

Keyword(s):

Free Surface ◽

Velocity Potential ◽

Hydrodynamic Forces ◽

The Body ◽

Source Distribution ◽

Accurate Estimation ◽

Forward Speed ◽

Surface Ship ◽

Wave Patterns ◽

Wigley Hull

In this paper, the hydrodynamic forces of a surface ship advancing in waves at constant forward speed are numerically calculated by using the 3-D source distribution techniques. The paper also deals with the numerical calculations of free surface flow around an advancing ship in calm water as well as in waves. The body boundary condition is linearised about the undisturbed position of the body and the free surface condition is linearised about the mean water surface. The potential is represented by a distribution of sources over the surface of the ship and its waterline. The problem is solved by the method of singularities distributed over the hull surface. Hess & Smith method is used to obtain the density of these singularities. The numerical solution of the surface ship case is approximately obtained by considering the hull as a position of plane polygonal elements, bearing a constant singularity distribution. The velocity potential of any particular point in the free surface around the moving hull is determined by using the 3-D Green function with forward speed which satisfies the boundary conditions for a pulsating source in the fluid. Contours of wave patterns around moving surface ships are calculated from the velocity potential. The numerical accuracy of the computer code is firstly checked by calculating the velocity potential of a translating, pulsating unit source with arbitrary frequency and forward speed. Free surface wave patterns generated by a Wigley hull advancing with steady forward speed are calculated by using this code. Some corresponding hydrodynamic coefficients of heave and pitch modes for the Wigley hull has been calculated. Exciting forces and motion amplitudes are also investigated. The numerical result of this code is validated by comparing the calculated results with the experimental ones and those calculated by other methods. From the comparison, the results predicted by the present calculations are found in fairly good agreement with the experiment. Finally, the effects of motion amplitude on the free surface elevation are analyzed. These will be helpful for the accurate estimation of sea keeping problems for a ship advancing in waves.

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Dynamics of comets in the collapsing protosolar nebula

International Astronomical Union Colloquium ◽

10.1017/s0252921100031225 ◽

1999 ◽

Vol 173 ◽

pp. 45-50

Author(s):

L. Neslušan

Keyword(s):

Solar System ◽

Velocity Distribution ◽

Oort Cloud ◽

Interstellar Clouds ◽

Protosolar Nebula ◽

Moving Bodies

AbstractComets are created in the cool, dense regions of interstellar clouds. These macroscopic bodies take place in the collapse of protostar cloud as mechanically moving bodies in contrast to the gas and miscroscopic dust holding the laws of hydrodynamics. In the presented contribution, there is given an evidence concerning the Solar system comets: if the velocity distribution of comets before the collapse was similar to that in the Oort cloud at the present, then the comets remained at large cloud-centric distances. Hence, the comets in the solar Oort cloud represent a relict of the nebular stage of the Solar system.

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