scholarly journals Numerical simulation of parametric resonance in point absorbers using a simplified model

2021 ◽  
Author(s):  
Adi Kurniawan ◽  
Thanh Toan Tran ◽  
Scott A. Brown ◽  
Claes Eskilsson ◽  
Jana Orszaghova ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Parametric Resonance ◽  
Simplified Model ◽  
Point Absorbers

Numerical Simulation and Analysis on the Impact Effect of Cylindrical Projectile Impacting Shelled Explosive

2013 ◽  
Vol 710 ◽  
pp. 320-324
Author(s):  
Ying Zi Jiang ◽  
Wei Li Wang ◽  
Xue Feng Huang ◽  
Lei Fu ◽  
Zhuang Qing Fan
Keyword(s):  
Numerical Simulation ◽  
Energy Criterion ◽  
Critical Energy ◽  
Simplified Model ◽  
Initiation Point ◽  
4340 Steel ◽  
Simulation Results ◽  
The Impact ◽  
Explosive Detonation ◽  
Critical Initiation

The numerical simulation of shelled Comp.B explosive was studied following the Lee-Tarver ignition and growth model when it was impacted respectively by 4340 Steel, OFHC and 93#W projectile with the same mass; the influences on explosive detonation of the initiation process, the material of projectile and the L/D ratio of projectile were analyzed; the critical initiation speeds of the projectiles of three different materials with different L/D ratio were gained. In order to verify the simulation results, the questions were calculated by the theoretical simplified model, the results of the theoretical calculation and the numerical simulation accorded well based on critical energy criterion. The results show that the capability of igniting explosive, the first is 93#W, the second is OFHC, the last is 4340 Steel; The initiation point were not on the interface of shell and explosive, and the faster of the impacting velocity, the initiation point closer the interface; the bigger of the L/D ratio of projectile, the higher of the critical initiation speed.

scholarly journals Numerical simulation of air cavity under a simplified model-scale hull form

2020 ◽  
Vol 5 (1) ◽  
pp. 68-72
Author(s):  
Konstantin I. Matveev
Keyword(s):  
Numerical Simulation ◽  
Simplified Model ◽  
Hull Form ◽  
Air Cavity ◽  
Model Scale

On the Effect of Water on Deck on Ship Motion

2002 ◽  
Author(s):  
Dimitris Spanos ◽  
Apostolos Papanikolaou ◽  
George Tzabiras
Keyword(s):  
Numerical Simulation ◽  
Satisfactory Agreement ◽  
Simulation Method ◽  
Interaction Force ◽  
Ship Motion ◽  
Simplified Model ◽  
Ship Motions ◽  
Efficient Simulation ◽  
Water On Deck ◽  
Present Simulation

The effect of trapped water on deck or the interior compartments of ships on ship motions is closely investigated by use of a non-linear numerical simulation method. The employed method enables the efficient simulation of the wave excited, coupled ship – trapped water motions and proves to be a very valuable tool for the assessment of the survivability of flooded ships in waves. A detailed study has been carried out to more carefully investigate the coupling effects between the ship and the floodwater mass that can be expressed through a resultant interaction force. This interaction force has been approximated both by a simplified model employed by the present simulation method and also by a more accurate CFD code and satisfactory agreement between the results of both approaches has been obtained.

Numerical Simulation of Taylor Couette Flow in Bioreactor

2011 ◽  
Vol 236-238 ◽  
pp. 1000-1004
Author(s):  
Li Ye ◽  
Zheng Ming Tong ◽  
Jai Lei Lu ◽  
Kai Zhu ◽  
Chao Li
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Flow Field ◽  
Couette Flow ◽  
Bottom Wall ◽  
Simplified Model ◽  
Middle Position ◽  
Whole Space ◽  
Taylor Couette ◽  
Taylor Couette Flow

Taylor Couette flow in bioreactor at different Re values is researched numerically by means of establishing a simplified model. Numerical results indicate that vortex appears earlier in the vicinity of bottom wall than in the vicinity of top free surface. As Re number increases, vortexes generate from both ends towards middle area of flow field and will fill the whole space when critical Re value is reached. Although all vortexes look the same in structure, intensities of them are widely divergent. The strength of vortex at bottom wall is more intensive than that at top free surface, while the vortex at middle position is the weakest.

Numerical simulation of air purging conditions during steel sheet temper rolling process

2017 ◽  
Vol 08 (01) ◽  
pp. 1750007 ◽  
Author(s):  
Siyu Dai ◽  
Yonglin Kang ◽  
Guoming Zhu ◽  
Xiaofei Zheng ◽  
Yuhui Wen
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Surface Quality ◽  
Working Conditions ◽  
Steel Sheet ◽  
Rolling Process ◽  
Simplified Model ◽  
Temper Rolling ◽  
Structured Grids

The application of the lubricant in the temper rolling process of tinplate manufacturing improves the mechanical properties and surface quality of the steel sheet. The removal of the residual lubricant deserves and has rarely been studied via numerical simulation. A simplified model of a single stand temper mill was established and was discretized into cells of block-structured grids. The criterion whether the lubricant could be removed was decided via multiphase simulation of a smaller model. Three parameters, the gap between the deflector and the rolls, the length of an additional baffle and the velocity of the purging air, were considered and scores of different working conditions were performed. The shapes of the steel sheet between the temper rolls and the bridle roll were also studied to screen out the conditions that the sheet could move steadily.

A Comprehensive Heat Transfer Study Inside a Steam Turbine Valve: Experiment, Numerical Simulation and Simplified Model

2021 ◽  
Author(s):  
Xu Zhang ◽  
Hongyi Shao ◽  
Wenwu Zhou ◽  
Wei Zhe Wang ◽  
YingZheng Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Steam Turbine ◽  
Transfer Process ◽  
Electric Heating ◽  
Heating System ◽  
Heat Transfer Process ◽  
Thermal Design ◽  
Simplified Model ◽  
Operational Flexibility

Abstract In a steam turbine system, one of the main factors limiting the operational flexibility is the thermal stress associated with a high temperature gradient within the control valves, which often leads to structural damage during frequent start-up and shut-down cycles. One possible solution is to utilize an electric heating system with appropriate insulation to decrease the warm-up time. Here, an experiment and a numerical simulation were performed using a scaled turbine valve equipped with an electric heating system to understand the heat transfer process. The experiment was conducted at Shanghai Jiao Tong University and had a duration of 100 hours, including three heating-cooling cycles and two heat preservation states. The simulation, which used the commercial software Ansys Fluent 2019 R1 with the finite volume method, was performed to model the experimental heat transfer process. The simulated results showed less than 10% deviation from the measured temperatures. To further improve the computing efficiency, a simplified model based on the lumped parameter method was proposed and validated. This model can predict the valve temperature in less than 1 minute and showed good agreement for all of the studied cases. The ability of the simplified model to simulate the valve heating-cooling cycles at a high efficiency could accelerate the thermal design process to improve the operational flexibility of steam turbines in the future.

scholarly journals A simplified model for numerical simulation of laser metal deposition process with beam oscillation

2018 ◽  
Vol 1109 ◽  
pp. 012006 ◽  
Author(s):  
S Y Ivanov ◽  
A Artinov ◽  
E A Valdaytseva ◽  
S L Stankevich ◽  
G A Turichin
Keyword(s):  
Numerical Simulation ◽  
Deposition Process ◽  
Metal Deposition ◽  
Simplified Model ◽  
Laser Metal Deposition ◽  
Beam Oscillation

scholarly journals Flow Separation Control in a Curved Diffuser with Rigid Traveling Wave Wall and Its Mechanism

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 192 ◽  
Author(s):  
Weiyu Lu ◽  
Guoping Huang ◽  
Jinchun Wang ◽  
Yuxuan Yang
Keyword(s):  
Numerical Simulation ◽  
Flow Control ◽  
Flow Separation ◽  
Traveling Wave ◽  
Linear Stability Theory ◽  
Simplified Model ◽  
Separation Flow ◽  
Flow Separation Control ◽  
Fast Fourier Transform Analysis ◽  
Unsteady Separation

Traveling wave wall is a useful method to suppress flow separation. However, the interaction between the traveling wave wall and unsteady separation flow is complex, which causes difficulty in discovering the corresponding mechanism. To reveal the mechanism of traveling wave wall control, numerical simulation of a separated curved diffuser using rigid traveling wave wall flow control is performed, which shows some unique characteristics. Then, a nonlinear simplified model is used to explain this phenomenon in flow control in consideration of nonlinear dynamics and order of degree. Flow field data from the numerical simulation are further analyzed using fast Fourier transform analysis, linear stability theory of free shear layers, and the nonlinear simplified model to reveal the control mechanism of traveling wave wall.

scholarly journals A Simplified Model for a Nonlinear Tidal Effect on Accretion Disks in CVS

1993 ◽  
Vol 134 ◽  
pp. 371-371
Author(s):  
Zhong-Yong Zhang ◽  
Jian-Sheng Chen
Keyword(s):  
Numerical Simulation ◽  
Accretion Disk ◽  
Accretion Disks ◽  
Dissipation Function ◽  
Tidal Effect ◽  
Simplified Model ◽  
Two Dimensional ◽  
Tidal Dissipation ◽  
Tidal Torque ◽  
Dwarf Nova

AbstractThis paper investigates the tidal effect on accretion disk in CVs and sets up a simplified model in which the secondary’s gravitation is substituted by a mean tidal torque. We find that a linear tidal torque will not be able to maintain an equilibrium disk. By using the result of the radius of the equilibrium disk approximately equals to the tidal radius, which was obtained by using the two dimensional numerical simulation invoking nonlinear tidal effect, we give the modified tidal dissipation function for our simplified model which could be used to interpret the outburst of the dwarf nova with tidal effect. The paper also shows that the radius of an equilibrium disk with a torus is slightly small than the Lubow-Shu radius, and the tidal effect may also cause the cycle of quiescence-superoutburst in addition to the cycle of quiescence-outbursts-superoutburst.

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