Experimental results on synchronization times and stable states in locally coupled light-controlled oscillators

2009 ◽  
Vol 367 (1901) ◽  
pp. 3267-3280 ◽  
Author(s):  
Nicolas Rubido ◽  
Cecilia Cabeza ◽  
Arturo C. Martí ◽  
Gonzalo Marcelo Ramírez Ávila
Keyword(s):  
Numerical Simulations ◽  
Coupling Strength ◽  
Coupled Oscillators ◽  
Initial Conditions ◽  
Experimental Studies ◽  
Numerical Results ◽  
Experimental Results ◽  
Stable States ◽  
Relaxation Oscillators ◽  
Local Coupling

Recently, a new kind of optically coupled oscillators that behave as relaxation oscillators has been studied experimentally in the case of local coupling. Even though numerical results exist, there are no references about experimental studies concerning the synchronization times with local coupling. In this paper, we study both experimentally and numerically a system of coupled oscillators in different configurations, including local coupling. Synchronization times are quantified as a function of the initial conditions and the coupling strength. For each configuration, the number of stable states is determined varying the different parameters that characterize each oscillator. Experimental results are compared with numerical simulations.

Synchronization in Relaxation Oscillator Networks with Conduction Delays

2001 ◽  
Vol 13 (5) ◽  
pp. 1003-1021 ◽  
Author(s):  
Jeffrey J. Fox ◽  
Ciriyam Jayaprakash ◽  
DeLiang Wang ◽  
Shannon R. Campbell
Keyword(s):  
Numerical Simulations ◽  
Coupled Oscillators ◽  
Initial Conditions ◽  
Relaxation Oscillator ◽  
Phase Lag ◽  
Relaxation Oscillators ◽  
Oscillator Networks ◽  
Coupled Networks ◽  
Parameter Values ◽  
Zero Phase

We study locally coupled networks of relaxation oscillators with excitatory connections and conduction delays and propose a mechanism for achieving zero phase-lag synchrony. Our mechanism is based on the observation that different rates of motion along different nullclines of the system can lead to synchrony in the presence of conduction delays. We analyze the system of two coupled oscillators and derive phase compression rates. This analysis indicates how to choose nullclines for individual relaxation oscillators in order to induce rapid synchrony. The numerical simulations demonstrate that our analytical results extend to locally coupled networks with conduction delays and that these networks can attain rapid synchrony with appropriately chosen nullclines and initial conditions. The robustness of the proposed mechanism is verified with respect to different nullclines, variations in parameter values, and initial conditions.

scholarly journals Study of the Planar Rocking-Block Dynamics With Coulomb Friction: Critical Kinetic Angles

2012 ◽  
Vol 8 (2) ◽  
Author(s):  
Hongjian Zhang ◽  
Bernard Brogliato ◽  
Caishan Liu
Keyword(s):  
Numerical Simulations ◽  
Coulomb Friction ◽  
Numerical Scheme ◽  
Numerical Results ◽  
Experimental Results ◽  
Restitution Coefficient ◽  
Rocking Block ◽  
Kinetic Angle ◽  
Multiple Impact ◽  
Impact With Friction

The objective of this paper is to show, through the planar rocking block example, that kinetic angles play a fundamental role in multiple impact with friction. Even in the presence of Coulomb friction, a critical kinetic angle θcr is exhibited that allows one to split the blocks into two main classes: slender blocks with a kinetic angle larger than θcr, and flat blocks with a kinetic angle smaller than θcr. The value of θcr varies with the friction value, but it is independent of the restitution coefficient (normal dissipation). Numerical results are obtained using a multiple impact law recently introduced by the authors. Some comparisons between numerical and experimental results that validate the used model and numerical scheme are presented. However, this paper is mainly based on numerical simulations.

scholarly journals DESIGN AND ANALYSIS OF AN AERODYNAMIC DOWNFORCE PACKAGE FOR A FORMULA STUDENT RACE CAR

2017 ◽  
Vol 18 (2) ◽  
pp. 212-224
Author(s):  
Muhammad Abid ◽  
Hafiz Abdul Wajid ◽  
Muhammad Zohair Iqbal ◽  
Shayan Najam ◽  
Ali Arshad ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Experimental Studies ◽  
Numerical Results ◽  
Experimental Results ◽  
Race Car ◽  
Rear Wing ◽  
Computational Fluid Dynamics Cfd ◽  
Front Wing

This paper presents design of aerodynamic downforce generating devices (front wing, rear wing and diffuser) to enhance the performance of the Formula Student Race Car using numerical and experimental studies. Numerical results using computational fluid dynamics (CFD) studies were primarily validated with the experimental results performed in the wind tunnel. It was concluded that the use of a downforce package can enhance the performance of the vehicle in the competition.

scholarly journals Theoretical and experimental analysis of the exact receptance function of a clamped-clamped beam with concentrated masses

2020 ◽  
Author(s):  
Nguyen Viet Khoa ◽  
Dao Thi Bich Thao
Keyword(s):  
Dynamic Response ◽  
Numerical Simulations ◽  
Experimental Analysis ◽  
Arbitrary Point ◽  
Peak Position ◽  
Numerical Results ◽  
Experimental Results ◽  
Harmonic Force ◽  
Concentrated Masses

This paper establishes the exact receptance function of a clamped-clamped beam carrying concentrated masses. In this paper, the derivation of exact receptance and numerical simulations are provided. The proposed receptance function is convenient to apply for predicting the dynamic response at arbitrary point of the beam acted by a harmonic force applied at arbitrary point. The influence of the concentrated masses on the receptance is investigated. The numerical simulations show that a peak in the receptance decreases when there is a mass located close to that peak position. The numerical results have been compared to the experimental results has to justify the theory.

scholarly journals Formation of Wide Binaries by Fragmentation

2001 ◽  
Vol 200 ◽  
pp. 13-22 ◽  
Author(s):  
Peter Bodenheimer ◽  
Andreas Burkert
Keyword(s):  
Numerical Simulations ◽  
Formation Mechanism ◽  
Initial Conditions ◽  
Theoretical Calculations ◽  
Numerical Results ◽  
Statistical Properties ◽  
Core Material

Although observations strongly suggest that fragmentation during the protostar collapse is the primary formation mechanism for wide binaries, the theoretical calculations as yet do not well explain the statistical properties of such systems. The results of a number of numerical simulations are discussed, and it is pointed out that, although fragmentation is obtained in such calculations, in many cases either the initial conditions are not realistic, or the calculations are insufficiently resolved, or the calculations have not been taken far enough to account for the accretion of most of the initial core material onto the components of the forming system. Certain aspects of the numerical results are, however, consistent with the fragmentation hypothesis.

Numerical Analysis of Oil/water Dispersion Interface Prediction in Horizontal Pipe Separators

2021 ◽  
Author(s):  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Numerical Simulations ◽  
Volume Fraction ◽  
Water Layer ◽  
Numerical Results ◽  
Experimental Results ◽  
Internal Diameter ◽  
Ansys Fluent ◽  
Horizontal Pipe ◽  
Water Dispersion ◽  
Vof Model

Abstract This paper presents the comparative study of experimental, modeling, and simulation results that are performed using commercially available ANSYS Fluent software to analyze the separation kinetics of oil and water in a horizontal separator at various velocities and watercuts. The horizontal pipe separator used in this study has an internal diameter of 0.0762 m and a length of 10.3 m separating oil and water with specific gravities of 1.0 and 0.857 and watercuts ranging from 20 to 90%. The mixture velocities studied are 0.08, 0.13, and 0.20 m/s. Numerical simulations are done using the hybrid Eulerian-Eulerian multifluid VOF model to study the effect of watercut on the creaming of the oil layer and sedimentation of the water layer respectively. As the mixture velocities increased, the initial length of separation increased like experimental results. As the watercut increased, the separation of water enhanced, while the oil creaming improved with the lowering of the watercut as expected. Numerical results showed good agreement for water/dispersion interface predictions for all the conditions studied. The CFD results are compared against experimental results obtained by Othman in 2010 and agree with the trend of separation. The numerical simulations gave insights into the velocity profiles in each of the layers such as creamed oil, sedimented water, and the layer of emulsion that is not separated. Also, the numerical results are validated against the extended Gassies (2008) model incorporating correlation for turbulent time decay and oil volume fraction proposed by Dabirian et al in 2018.

scholarly journals A FARM OF WAVE ACTIVATED BODIES FOR COASTAL PROTECTION PURPOSES

2012 ◽  
Vol 1 (33) ◽  
pp. 68 ◽  
Author(s):  
Elisa Angelelli ◽  
Barbara Zanuttigh
Keyword(s):  
Numerical Modelling ◽  
Numerical Simulations ◽  
Transmission Coefficient ◽  
Wave Energy ◽  
Numerical Results ◽  
Experimental Results ◽  
Coastal Protection ◽  
Basic Module ◽  
Wave Energy Converters ◽  
Mike 21

This paper aims at investigating the efficacy of a floating farm of wave energy converters for coastal protection purposes through physical and numerical modelling. The experiments were performed in 3D conditions on a basic module consisting of two staggered lines and three devices. The numerical simulations were carried out with the software MIKE 21 BW, developed by DHI Water & Environment & Health, and were calibrated based on the experimental results. Additional configurations were tested by varying the gap long-shore width and the device alignment. Despite the model limitations, i.e. the representation of the devices as fixed porous piles, the numerical results well approximate the average measured transmission coefficient and allow to derive a complete map of the hydrodynamics around the devices.

Numerical Analysis of the Influence of the Padding-Plate on the Extended End-Plate Connection

2014 ◽  
Vol 578-579 ◽  
pp. 505-508
Author(s):  
Shao Qin Zhang ◽  
Lei Wu
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Load Capacity ◽  
Numerical Results ◽  
Experimental Results ◽  
End Plate ◽  
Extended End Plate ◽  
Plate Connection

In the present paper, we investigate the effect of a padding-plate on the behavior of extended end-plate semi-rigid connections. The numerical simulations were carried out for a standard extended end-plate connection joint without padding-plate and two connection joints with 4mm and 6mm thick padding-plates. The existing experimental results verified the validity of the numerical model. The numerical results have shown that a thin padding-plate will more or less decline the carrying load capacity of the connection joint but greatly improve the connect ductility. Filling a thin padding-plate in the end-plate connection is feasible and brings the forewarning function.

scholarly journals Synchronization dynamics of two mutually coupled 555-IC based electronic oscillators

2018 ◽  
Vol 64 (2) ◽  
pp. 107
Author(s):  
Moisés Santillán
Keyword(s):  
Mathematical Model ◽  
Coupling Strength ◽  
Frequency Ratio ◽  
Coupled Oscillators ◽  
Oscillatory System ◽  
Experimental Results ◽  
Large Set ◽  
Electronic Oscillators ◽  
Insight Into

We designed and implemented an electronic oscillatory system consisting of two mutually coupled oscillators (each one based on the 555-timer IC working in astable mode), and investigated its synchronization dynamics. For that purpose, we characterized the phase-lockingrhythms achieved in a large set of values of the uncoupled frequency ratio and of the coupling strength between both oscillators. We furtherdeveloped an ODE mathematical model that qualitative reproduces the obtained experimental results and provides further insight into thesystem behavior.

Numerical Simulations of Sloshing in Rectangular Tanks

2006 ◽  
Author(s):  
Samuel R. Ransau ◽  
Ernst W. M. Hansen
Keyword(s):  
Numerical Simulations ◽  
Small Amplitude ◽  
Three Dimensional ◽  
Numerical Results ◽  
Experimental Results ◽  
Non Linear ◽  
Forced Excitation

Simulations of two- and three-dimensional sloshing in rectangular tanks are performed using the commercial CFD code FLOW3D. Small amplitude freely oscillating sloshing and non-linear sloshing due to forced excitation were investigated. The results are compared to both experimental results and other numerical results; and tests are made with different grids. The purpose of this study was the validation of the new VOF algorithm under development at Flow Science and implemented in FLOW3D.

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