Theoretical and numerical investigations of wave resonance between two floating bodies in close proximity

2017 ◽  
Vol 29 (5) ◽  
pp. 805-816 ◽  
Author(s):  
Lei Tan ◽  
Guo-qiang Tang ◽  
Zhong-bing Zhou ◽  
Liang Cheng ◽  
Xiaobo Chen ◽  
...  
Keyword(s):  
Floating Bodies ◽  
Numerical Investigations ◽  
Wave Resonance ◽  
Close Proximity

Numerical Modelling of Wave Resonance in a Narrow Gap Between Two Floating Bodies in Close Proximity Using a Hybrid Model

2019 ◽  
Author(s):  
S. Yan ◽  
Q. W. Ma ◽  
Junxian Wang ◽  
Jinghua Wang
Keyword(s):  
Hybrid Model ◽  
Computational Domain ◽  
Narrow Gap ◽  
Viscous Effects ◽  
Floating Bodies ◽  
Nonlinear Potential Theory ◽  
Numerical Predictions ◽  
Wave Resonance ◽  
Close Proximity ◽  
Incident Waves

Abstract This paper presents a numerical investigation on the wave resonance in a narrow gap between two floating bodies in close proximity using a hybrid model, qaleFOAM, which combines a two-phase Navier-Stokes model (NS) and the fully nonlinear potential theory (FNPT) using a spatially hierarchical approach. The former governs the computational domain near the floating bodies and the gap, where the viscous effects are significant, and is solved by using OpenFOAM/InterDyMFoam. The latter covers the rest of the domain and solved by using the Quasi Lagrangian Eulerian Finite Element Method (QALE-FEM). The model is validated by comparing its numerical predictions with experimental data in the cases with linear incident waves. Systematic investigations using incident waves with different steepness are then followed to explore the nonlinear effects on the wave resonance.

Modelling of multi-bodies in close proximity under water waves—Fluid forces on floating bodies

2011 ◽  
Vol 38 (13) ◽  
pp. 1403-1416 ◽  
Author(s):  
Lin Lu ◽  
Bin Teng ◽  
Liang Sun ◽  
Bing Chen
Keyword(s):  
Water Waves ◽  
Floating Bodies ◽  
Fluid Forces ◽  
Close Proximity

Higher-order harmonic induced wave resonance for two side-by-side boxes in close proximity

2021 ◽  
Vol 33 (10) ◽  
pp. 102113
Author(s):  
Sheng-Chao Jiang ◽  
Wei Bai ◽  
Bin Yan
Keyword(s):  
Higher Order ◽  
Wave Resonance ◽  
Close Proximity

Guidance Solutions for Multiple Vehicle Assembly

2014 ◽  
Vol 1016 ◽  
pp. 797-801
Author(s):  
Mohamed Okasha
Keyword(s):  
Formation Flying ◽  
Function Theory ◽  
Assembly Process ◽  
Satellite Formation ◽  
Numerical Investigations ◽  
Future Mission ◽  
Close Proximity ◽  
Lyapunov’S Second Method ◽  
The Stability ◽  
Guidance Laws

This paper exploits the guidance algorithms to assembly multiple vehicle in close proximity. The objective is to move each vehicle in the assembly to its final location. The guidance laws are determined such that, each vehicle should attract to the others on long distances and avoid collision with them in short distances. These laws are based on Lyapunov’s second method that utilize the potential function theory to insure the stability of the assembly process. Numerical investigations were performed for different configurations of the assembly. The proposed algorithms may prove useful for future mission applications such as satellite formation flying, structures assembly in space and mobile robots control.

Experimental and numerical investigations into the drag characteristics of a pair of ellipsoids in close proximity

2002 ◽  
Vol 216 (2) ◽  
pp. 107-115 ◽  
Author(s):  
A F Molland ◽  
I K A P Utama
Keyword(s):  
Fluid Dynamics ◽  
Wind Tunnel ◽  
Diameter Ratio ◽  
Viscous Resistance ◽  
Numerical Work ◽  
Wind Tunnel Tests ◽  
Numerical Investigations ◽  
Close Proximity ◽  
Computational Fluid Dynamics Cfd ◽  
Low Speed Wind Tunnel

Investigations into the drag of ellipsoids in proximity have been carried out experimentally using a low-speed wind tunnel and numerically using a commercial computational fluid dynamics (CFD) code (CFXTM). The purpose of the investigations was to improve the understanding of the viscous resistance and viscous interaction effects between twin bodies in proximity, such as the hulls of a catamaran, and consequently to improve the techniques for estimating the resistance and powering of commercial catamarans. The wind tunnel tests were carried out on a single ellipsoid with a length-diameter ratio ( L/D) of 6.0 and a pair of similar ellipsoids in proximity at separation-length ratios ( S/L) of 0.27, 0.37, 0.47 and 0.57 at Reynolds number values up to 3.2 ×106. The ellipsoids thus represented a reflex (or reflected) model of a catamaran hull. In the numerical work, investigations were carried out on ellipsoids with the same geometry as those tested in the wind tunnel and ellipsoids with a larger length-diameter ratio. Results of the wind tunnel tests and numerical investigations are presented and compared. It is found from the investigations that viscous form effects and viscous interactions are present for such bodies and that CFD techniques can make very useful contributions to the investigations of these effects.

Numerical investigations on the interface mode in spin-wave resonance

1997 ◽  
Vol 170 (1-2) ◽  
pp. 22-28 ◽  
Author(s):  
M. Jackson ◽  
D. Mercier ◽  
J.C.S. Levy ◽  
J.S.S. Whiting
Keyword(s):  
Spin Wave ◽  
Numerical Investigations ◽  
Spin Wave Resonance ◽  
Wave Resonance ◽  
Interface Mode

Resonant Motion of Liquid Confined between Floating Structures

2014 ◽  
Vol 567 ◽  
pp. 289-294
Author(s):  
N.V. Nasma Noor ◽  
A.P. Shashikala
Keyword(s):  
Resonant Frequency ◽  
Frequency Domain Method ◽  
Diffraction Radiation ◽  
Floating Bodies ◽  
Floating Structures ◽  
Hydrodynamic Behaviour ◽  
Wave Elevation ◽  
Close Proximity ◽  
Multiple Floating Bodies ◽  
Two Bodies

Many applications occur in the field of marine hydrodynamics where two or more vessels are in sufficiently close proximity to experience significant wave action. The motion of such floating bodies in waves is frequency dependent. In the case of multiple floating bodies, when resonance occurs, the effect of confined liquid between the bodies has some serious implications on the safety and operation of the offloading system. The main objective of the work is to determine the hydrodynamic behaviour of two bodies freely floating in water. A frequency domain method is adopted for the prediction of the resonant frequency. 3D linear diffraction radiation analysis is used to solve the problem. Structures are modelled in ANSYS AQWA and analysed in selected range of frequency with different spacing. As the spacing increases the resonant frequency in roll is found to be decreasing for both ship and tugboat and the frequency shift between the two is increasing. The wave elevation pattern within the spacing has been observed and the result has been shown for different spacings.

scholarly journals Vortex Shedding From Hulls in Close Proximity With Relative Motion

2018 ◽  
Author(s):  
Ian A. Milne ◽  
J. Michael R. Graham
Keyword(s):  
Vortex Shedding ◽  
Significant Contribution ◽  
Pressure Field ◽  
Computational Results ◽  
Floating Bodies ◽  
Damping Coefficients ◽  
Close Proximity ◽  
Forced Roll ◽  
Offshore Industry ◽  
Liquid Natural Gas

The safe and efficient offloading of liquid natural gas (LNG) in a side-by-side configuration has emphasised the need to accurately quantify the hydrodynamic responses of floating bodies when located in very close proximity. A new series of computational results are presented for the forced roll of a hull in the presence of a second body representative of a floating FLNG facility. The vortex shedding phenomenon which provides a significant contribution to the damping of an isolated hull, is demonstrated to be modified by the presence of the second body. The total damping coefficients were found to be significantly reduced by approximately 50 percent for the very small gap widths considered. It is shown that in addition to the modification of the local shedding dynamics, the variation in the pressure field owing to the presence of the second body also contributes significantly to the reduction in the damping. The findings will be of particular interest to the offshore industry for improving and optimising offloading practices.

Effects of Vincristine on Endothelial Microtubules in the Spinal Cord

1976 ◽  
Vol 34 ◽  
pp. 58-59
Author(s):  
John L. Beggs ◽  
John D. Waggener ◽  
Wanda Miller
Keyword(s):  
Spinal Cord ◽  
Biological Activity ◽  
Horseradish Peroxidase ◽  
Transport Mechanism ◽  
Vasogenic Edema ◽  
Vesicular Transport ◽  
Close Proximity

Microtubules (MT) are versatile organelles participating in a wide variety of biological activity. MT involvement in the movement and transport of cytoplasmic components has been well documented. In the course of our study on trauma-induced vasogenic edema in the spinal cord we have concluded that endothelial vesicles contribute to the edema process. Using horseradish peroxidase as a vascular tracer, labeled endothelial vesicles were present in all situations expected if a vesicular transport mechanism was in operation. Frequently,labeled vesicles coalesced to form channels that appeared to traverse the endothelium. The presence of MT in close proximity to labeled vesicles sugg ested that MT may play a role in vesicular activity.

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