scholarly journals Numerical simulations of one laser-plasma model based on Poisson structure

2020 ◽  
Vol 405 ◽  
pp. 109172
Author(s):  
Yingzhe Li ◽  
Yajuan Sun ◽  
Nicolas Crouseilles
Keyword(s):  
Numerical Simulations ◽  
Poisson Structure ◽  
Laser Plasma ◽  
Plasma Model ◽  
Model Based

scholarly journals Model-Based Analysis of Yo-yo Throwing Motion on Single-Link Manipulator

2020 ◽  
Vol 32 (4) ◽  
pp. 822-831
Author(s):  
Hokuto Miyakawa ◽  
◽  
Takuma Nemoto ◽  
Masami Iwase
Keyword(s):  
Angular Velocity ◽  
Numerical Simulations ◽  
Integrated Model ◽  
Analysis Method ◽  
Model Based ◽  
Single Link ◽  
Throwing Motion ◽  
Model Based Analysis

This paper presents a method for analyzing the throwing motion of a yo-yo based on an integrated model of a yo-yo and a manipulator. Our previous integrated model was developed by constraining a model of a white painted commercial yo-yo and a model of a plain single-link manipulator with certain constraining conditions placed between two models. However, for the yo-yo model, the collisions between the string and the axle of the yo-yo were not taken into account. To avoid this problem, we estimate some of the yo-yo parameters from the experiments, thereby preserving the functionality of the model. By applying the new integrated model with the identified parameters, we analyze the throwing motion of the yo-yo through numerical simulations. The results of which show the ranges of the release angle and the angular velocity of the joint of the manipulator during a successful throw. In conclusion, the proposed analysis method is effective in analyzing the throwing motion of a manipulator.

Polarimetry data inversion in conditions of tokamak plasma: Model based tomography concept

2015 ◽  
Vol 96-97 ◽  
pp. 756-759
Author(s):  
B. Bieg ◽  
J. Chrzanowski ◽  
Yu. A. Kravtsov ◽  
D. Mazon
Keyword(s):  
Tokamak Plasma ◽  
Plasma Model ◽  
Model Based ◽  
Data Inversion

scholarly journals Model-based design of transverse wall oscillations for turbulent drag reduction

2012 ◽  
Vol 707 ◽  
pp. 205-240 ◽  
Author(s):  
Rashad Moarref ◽  
Mihailo R. Jovanović
Keyword(s):  
Turbulent Flow ◽  
Numerical Simulations ◽  
Eddy Viscosity ◽  
Traditional Approach ◽  
Turbulent Viscosity ◽  
Transverse Wall ◽  
Mean Velocity ◽  
Model Based ◽  
Turbulent Drag ◽  
Linearized Model

AbstractOver the last two decades, both experiments and simulations have demonstrated that transverse wall oscillations with properly selected amplitude and frequency can reduce turbulent drag by as much as $40\hspace{0.167em} \% $. In this paper, we develop a model-based approach for designing oscillations that suppress turbulence in a channel flow. We utilize eddy-viscosity-enhanced linearization of the turbulent flow with control in conjunction with turbulence modelling to determine skin-friction drag in a simulation-free manner. The Boussinesq eddy viscosity hypothesis is used to quantify the effect of fluctuations on the mean velocity in flow subject to control. In contrast to the traditional approach that relies on numerical simulations, we determine the turbulent viscosity from the second-order statistics of the linearized model driven by white-in-time stochastic forcing. The spatial power spectrum of the forcing is selected to ensure that the linearized model for uncontrolled flow reproduces the turbulent energy spectrum. The resulting correction to the turbulent mean velocity induced by small-amplitude wall movements is then used to identify the optimal frequency of drag-reducing oscillations. In addition, the control net efficiency and the turbulent flow structures that we obtain agree well with the results of numerical simulations and experiments. This demonstrates the predictive power of our model-based approach to controlling turbulent flows and is expected to pave the way for successful flow control at higher Reynolds numbers than currently possible.

Numerical simulations of semiconvection

2006 ◽  
Vol 2 (S239) ◽  
pp. 317-319 ◽  
Author(s):  
Guillaume P. Bascoul
Keyword(s):  
Prandtl Number ◽  
Numerical Simulations ◽  
Massive Star ◽  
Scaling Laws ◽  
Main Sequence ◽  
Neutral Layer ◽  
The Core ◽  
Model Based ◽  
Thermohaline Convection ◽  
High Prandtl Number

AbstractUsing a semiconvective model based on thermohaline convection, we investigate the case of an expanding core of a main-sequence massive star. The numerical simulations at high Prandtl number show a flow consistent with the assumption that a dynamically neutral layer sits between the core and the radiative envelope. More simulations at low Prandtl number are needed to infer scaling laws applicable to astrophysical regimes.

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