Numerical Simulation of Maneuvering of "Naniwa-maru," A Full-scale Reconstruction of Sailing Trader of Japanese Heritage

2003 ◽  
Author(s):  
Yutaka Masuyama ◽  
Kensaku Nomoto ◽  
Akira Sakurai
Keyword(s):  
Numerical Simulation ◽  
Equations Of Motion ◽  
Time History ◽  
Ship Motions ◽  
Measured Time ◽  
Generic Class ◽  
History Of ◽  
Heading Angle ◽  
Ship Performance ◽  
Rudder Angle

Numerical simulation of maneuvering of “Naniwa-maru" was performed to clarify the maneuver characteristics in particular with wearing operation. "Naniwa-maru" belongs to a type called Higaki-kaisen, and the Higaki-kaisen is a type of the more generic class of vessels named "Bezai-ship". Bezai-ship are typical Japanese sailing traders in the 18th to the mid- 19th century which have different appearance and construction from those of Western tall ships. The present paper shows the numerical simulation of her wearing operation, and the results compared with the measured data. The equations of motion dealt with coupled ship motions of surge, sway, roll and yaw with co-ordinate system using horizontal body axes. The numerical simulation indicates ship response according to the measured time history of rudder angle, and shows the ship trajectory and the sailing state parameters such as heading angle, leeway angle, heel angle and velocity. The calculated results indicated the ship performance very well.

Numerical Simulation and Experimental Study on Fluid-Filled Hemispherical Shell under Impact

2013 ◽  
Vol 364 ◽  
pp. 172-176
Author(s):  
Hui Wei Yang ◽  
Bin Qin ◽  
Zhi Jun Han ◽  
Guo Yun Lu
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Impact Load ◽  
Elastic Recovery ◽  
Plastic Hinge ◽  
Time History ◽  
Hemispherical Shell ◽  
History Of ◽  
Local Impact ◽  
The Impact

The dynamic response of fluid-filled hemispherical shell in mass impact is studied by experiment using DHR9401. Combining the time history of impact force with experimental observation of the deformation process, it can be seen that the dynamic response can be divided into four stages: the flattening around the impact point, the forming and expanding outward of shell plastic hinge, the plastic edge region flatten by the punch, and elastic recovery. The experimental results show that: Because the shell filled with liquid, the local impact load that the shell suffered is translated into area load and loads on the inner shell uniformly, so that it has a high carrying capacity. Numerical simulation is used to study the time history of energy absorption of different shell structures. The result shows that the crashworthiness of sandwich fluid-filled shell is improved greatly. Under the certain impact energy, deformation of its inner shell is very small, which can provide effective security space.

Governing Equations of Motion of Walking Behavior of Unanchored Flat-Bottom Cylindrical Shell Tanks Subjected to Horizontal Sinusoidal Ground Motion

2006 ◽  
Author(s):  
Tomoyo Taniguchi ◽  
Koji Imai
Keyword(s):  
Cylindrical Shell ◽  
Ground Motion ◽  
Equations Of Motion ◽  
Time History ◽  
Governing Equations ◽  
Flat Bottom ◽  
Walking Behavior ◽  
Walking Motion ◽  
Rocking Motion ◽  
History Of

The governing equations of motion of walking phenomena of unanchored flat-bottom cylindrical shell tanks subjected to horizontal sinusoidal ground motion are examined. The equations of motion are derived through variational approach. The physical quantities related to the walking phenomena are the mass of tank itself, tank content, the effective mass of liquid for bulging motion, that for rocking motion, that for rocking-bulging interaction motion, and friction force including self-weight reduction effects. The roles of each physical quantity during the walking motion are clearly identified. Comparison of the time history of experimental results and that of analytical ones corroborates accuracy of the proposed equations of motion.

scholarly journals Direct drive double shell target implosion hydrodynamics on OMEGA

2005 ◽  
Vol 23 (2) ◽  
pp. 187-192 ◽  
Author(s):  
GEORGE A. KYRALA ◽  
NORMAN DELAMATER ◽  
DOUGLAS WILSON ◽  
JOYCE GUZIK ◽  
DON HAYNES ◽  
...  
Keyword(s):  
Time History ◽  
Direct Drive ◽  
National Ignition Facility ◽  
Initial Stage ◽  
Heat Effects ◽  
Measured Time ◽  
History Of ◽  
Indirect Drive ◽  
Omega Laser ◽  
And Performance

Imploding indirect-drive double shell targets may provide an alternative, non-cryogenic path to ignition at the National Ignition Facility (NIF). Experiments are being pursued at OMEGA to understand the hydrodynamics of these implosions and the possibility of scaling it to the NIF design. We have used 40 beams from the OMEGA laser to directly drive the capsules, and we have used the remaining 20 beams to backlight the imploding shells from two different directions at multiple times. We will review the recent experiments to measure the hydrodynamics of the targets using two-view X-ray radiography of the capsules. We will present data on measured yields from the targets. We will present a measured time history of the hydrodynamics of the implosion. Experiments were pursued using direct drive in which the M-band effect (experienced in the indirect drive experiments) could be eliminated or controlled. It was learned in the direct drive experiments that the best performing capsules were those that had a thin outer layer of gold. This effectively causes M-band pre-heat effects giving implosion hydrodynamics and performance closer to the indirect drive case. We will review the methods used to radiograph the targets and the techniques used to extract useful information to compare with calculations. The effect of imperfections in the target construction will be shown to be minimal during the initial stage of implosion. The yields from the targets were observed to be uniformly low compared to indirect-drive.

scholarly journals Effect of Pulse Shape and Duration on Dynamic Response of a Forging System

2019 ◽  
Vol 13 (4) ◽  
pp. 226-232
Author(s):  
Arkadiusz Trąbka
Keyword(s):  
Dynamic Response ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Time History ◽  
Pulse Load ◽  
Negative Effects ◽  
Maximum Displacement ◽  
Soil Settlement ◽  
History Of ◽  
Three Degrees Of Freedom

Abstract Forging hammers are machines whose operation causes negative effects both at the place of their foundation (the soil settlement) and in their surroundings (e.g., vibrations propagating to the other devices, noise, etc.). Knowledge of the parameters characterizing the time history of the force that arises as a result of impact of a ram on a shaped material is of fundamental importance for the correct analysis of both the structure of the hammer and its impact on the surroundings. In the paper, the effect of the shape and duration of a pulse load on the dynamic response of a hammer-foundation forging system was assessed. An analytical method of description of the forces that arise as a result of impact of the ram on the forged material, using different forms of pulses was presented. The forces defined in this way as loads in a mathematical model of three degrees of freedom forging system were used. The equations of motion derived from d’Alembert’s principle were solved numerically in the Matlab program. The analyses for eight forms of the pulse loads with the same pulse sizes but different durations were performed. The results in the graphs were presented. It was found, among other things, that a greater impact on the maximum displacement, velocity and acceleration of each component of the hammer-foundation system as well as on the maximum forces transmitted to the soil has the duration of a pulse than its shape.

scholarly journals Application of harmonic balance method for solving non-linear equations of motion

2018 ◽  
Vol 182 ◽  
pp. 02024
Author(s):  
Robert Kostek
Keyword(s):  
Harmonic Balance ◽  
Equations Of Motion ◽  
Linear Equations ◽  
Harmonic Balance Method ◽  
Time History ◽  
Balance Method ◽  
Non Linear ◽  
Time Histories ◽  
History Of ◽  
Non Linear Equations

This article presents the advantages and limitations of a harmonic balance method applied for solving non-linear equations of monition. This method provides an opportunity to find stable and unstable periodic solutions, which was demonstrated for a few equations. An error of solution decreases rapidly with increase of number of harmonics for smooth time history of acceleration, which shows convergence; whereas, for discontinuous time histories, this method is not effective.

3-Dimensional Numerical Simulation of Ship Motion in Pack Ice

2012 ◽  
Author(s):  
Dexin Zhan ◽  
David Molyneux
Keyword(s):  
Numerical Simulation ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Ship Motion ◽  
Ship Motions ◽  
Discrete Element Modeling ◽  
Ship Maneuvering ◽  
3 Dimensional ◽  
Pack Ice ◽  
Ice Concentration

In OMAE2010, the authors presented a two dimensional numerical simulation for predicting ship maneuvering in pack ice. This paper is an expansion of this analysis to include a three dimensional numerical simulation for an arctic drill ship moving in pack ice (with ice concentration up to 90%) using a discrete element modeling program (DECICE3D) combined with a ship maneuvering code (SML). The mathematical models of ship motion, ice motion and ship-ice interaction are introduced in the paper. Ship motions of steady drift angle, turning about a turret, turning circle and zigzag maneuvers in pack ice are simulated. The results of the simulations are compared with experimental data or results of simulations for ice free conditions. A sensitive study for the effects of the mass damping term used in the equations of motion is conducted.

The deformation of steep surface waves on water - I. A numerical method of computation

1976 ◽  
Vol 350 (1660) ◽  
pp. 1-26 ◽  
Keyword(s):  
Surface Waves ◽  
Velocity Potential ◽  
Equations Of Motion ◽  
Normal Component ◽  
Time History ◽  
Finite Amplitude ◽  
Asymmetric Distribution ◽  
Time Step ◽  
Analytical Approximations ◽  
History Of

Plunging breakers are beyond the reach of all known analytical approximations. Previous numerical computations have succeeded only in integrating the equations of motion up to the instant when the surface becomes vertical. In this paper we present a new method for following the time-history of space-periodic irrotational surface waves. The only independent variables are the coordinates and velocity potential of marked particles at the free surface. At each time-step an integral equation is solved for the new normal component of velocity. The method is faster and more accurate than previous methods based on a two dimensional grid. It has also the advantage that the marked particles become concentrated near regions of sharp curvature. Viscosity and surface tension are both neglected. The method is tested on a free, steady wave of finite amplitude, and is found to give excellent agreement with independent calculations based on Stokes’s series. It is then applied to unsteady waves, produced by initially applying an asymmetric distribution of pressure to a symmetric, progres­sive wave. The freely running wave then steepens and overturns. It is demonstrated that the surface remains rounded till well after the over­turning takes place.

URANS Simulation of ONR Tumblehome Parametric Rolling in Regular Head Waves

2019 ◽  
Author(s):  
Zhiguo Zhang ◽  
Lixiang Guo ◽  
Shuang Wang ◽  
Ye Yuan ◽  
Can Chen
Keyword(s):  
Experimental Data ◽  
Time History ◽  
Head Wave ◽  
Ship Motions ◽  
Parametric Rolling ◽  
Wave Characteristic ◽  
Head Waves ◽  
History Of ◽  
Onr Tumblehome ◽  
Regular Head Waves

Abstract In this paper, an in-house CFD code HUST-Ship is used for the numerical simulation of parametric rolling phenomena of ONR Tumblehome in regular head wave. Preliminary resistance and roll decay simulations at Fr = 0.2 were carried out and compared with existed INSEAN experimental data. Following, three DOFs’ ship motions in regular head wave with an initial roll angle of 30 degrees was calculated to examine the possibility of occurrence of parametric rolling. Finally, a simulation without initial roll disturbance was performed to investigate its influence to the steady roll amplitude. By conducting fast Fourier transform of the time history of motions, forces and moments, the characteristics are analyzed and co-related with wave frequency. Results can be concluded that the in-house code has the ability to perform the parametric rolling simulation, and that the final steady roll amplitude is not affected by the initial disturbance. In addition, heave and pitch motions are dominantly affected by wave characteristic, roll frequency is about half that of wave, and that forces and moments in x direction exhibit high-order non-linearity.

Governing Equations of Motion of Walking Behavior of Unanchored Flat-Bottom Cylindrical Shell Tanks During Free Rocking Motion

2005 ◽  
Author(s):  
Tomoyo Taniguchi ◽  
Koji Imai
Keyword(s):  
Cylindrical Shell ◽  
Friction Force ◽  
Equations Of Motion ◽  
Time History ◽  
Governing Equations ◽  
Flat Bottom ◽  
Walking Behavior ◽  
Walking Motion ◽  
Rocking Motion ◽  
History Of

The governing equations of motion of the walking phenomena of the unanchored flat-bottom cylindrical shell tanks are examined. This paper considers that the walking phenomena is followed by the rocking motion of the tanks, since the rocking motion induces the reduction of self-weight and consequently reduces friction force between the tank and the foundation. The equations of motion are derived through variational approach. The physical quantities related to the walking phenomena are the mass of tank itself, tank content, the effective mass of liquid for bulging motion, for rocking motion and for rocking-bulging interaction motion, and friction force including self-weight reduction effects. The roles of every physical quantity related to the walking motion are clearly identified. The time history of the walking motion of the model tank induced by the initial enforced uplift angle and then gently released is well computed by the proposed procedure.

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