Near Wall Deformation and Dynamics of Falling Droplets Under the Effect of Electric Field

2017 ◽  
Author(s):  
Esmaiil Ghasemisahebi ◽  
Hassan Bararnia ◽  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin
Keyword(s):  
Electric Field ◽  
Open Source ◽  
Three Dimensional ◽  
Numerical Data ◽  
Grid Refinement ◽  
Drop Dynamics ◽  
Adaptive Grid Refinement ◽  
Wall Deformation ◽  
Initial Drop ◽  
Side Walls

In this paper, dynamics of the falling droplet under gravity near the wall has been studied numerically. Electrohydrodynamics (EHD) force has been applied to the falling drop to investigate the effect of electric field on its behavior. In order to study the effects of wall boundaries on falling drop dynamics the initial drop is placed close to side walls. The open-source volume-of-fluid solver, Gerris has been used due to its dynamic adaptive grid refinement feature. Three-dimensional study of drops falling under gravity and nonsymmetrical electric field for different ratios of density and viscosity have been studied on the drop dynamics. The numerical results of EHD field and falling drop have been validated with previous analytical, experimental and numerical data. The parameters that govern the dynamics are the Galilee (Ga) and the Bond (Bo) numbers.

A DNS Study of Falling Droplets Under Effects of Electric Field

2017 ◽  
Author(s):  
Esmaiil Ghasemisahebi ◽  
Hassan Bararnia ◽  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin
Keyword(s):  
Electrical Conductivity ◽  
Electric Field ◽  
Open Source ◽  
External Electric Field ◽  
Three Dimensional ◽  
Numerical Results ◽  
Grid Refinement ◽  
Adaptive Grid Refinement ◽  
Side Walls ◽  
Density Ratios

In this study deformation and breakup of a falling drop which is surrounded by another liquid are modeled numerically. The drop is influenced by an external electric field which is applied uniformly on the side walls of the domain. An open-source volume-of-fluid solver, Gerris with dynamic adaptive grid refinement has been used for numerically modeling the three-dimensional deformation of a falling droplet. The numerical results are presented for various values of density ratios and electrical conductivity and permittivity. The current numerical results are compared with previous experimental and analytical works which shows a great agreement between them.

3D interpretation of electromagnetic data using a modified extended Born approximation

Geophysics ◽  
2003 ◽  
Vol 68 (1) ◽  
pp. 127-137 ◽  
Author(s):  
Hung‐Wen Tseng ◽  
Ki Ha Lee ◽  
Alex Becker
Keyword(s):  
Electric Field ◽  
Born Approximation ◽  
Three Dimensional ◽  
Numerical Data ◽  
Integral Equation Method ◽  
Approximation Technique ◽  
Induction Process ◽  
The Fourier Transform ◽  
Em Tomography ◽  
And Inversion

We present a new method, dubbed the modified extended Born approximation (MEBA), for efficient three‐dimensional (3D) simulation and inversion of geophysical frequency‐domain electromagnetic (EM) data for a targeted object lodged in a layered half‐space. Based on the integral equation method and modified from an extended Born approximation technique, the MEBA method calculates the total electric field in an electrical conductivity inhomogeneity without any need for solving a huge matrix equation. This is done by multiplying the background electric field by a depolarization tensor. The Fourier transform and the convolution theorem are used to dramatically increase the computational efficiency. Comparisons of MEBA‐generated numerical data for tabular targets with data generated by other means are used to verify the scheme and check its range of validity. The results indicate that the MEBA technique yields better accuracy when current channeling in the conductivity anomaly dominates over the induction process. The MEBA algorithm has been incorporated into a least‐squares inversion scheme which is used to interpret borehole‐to‐surface EM tomography field data. The survey served to monitor the subsurface conductivity change associated with the extraction of a volume of saltwater previously injected into a known aquifer.

The Effect of Roughness Features on Mos Surface Electric Field and Fowler-Nordheim Tunneling Behavior

1997 ◽  
Vol 473 ◽  
Author(s):  
Heng-Chih Lin ◽  
Edwin C. Kan ◽  
Toshiaki Yamanaka ◽  
Simon J. Fang ◽  
Kwame N. Eason ◽  
...  
Keyword(s):  
Electric Field ◽  
Three Dimensional ◽  
Tunneling Current ◽  
Gate Oxide ◽  
Oxide Thickness ◽  
Interface Roughness ◽  
Normal Electric Field ◽  
Surface Electric Field ◽  
Tunneling Behavior ◽  
Nordheim Tunneling

ABSTRACTFor future CMOS GSI technology, Si/SiO2 interface micro-roughness becomes a non-negligible problem. Interface roughness causes fluctuations of the surface normal electric field, which, in turn, change the gate oxide Fowler-Nordheim tunneling behavior. In this research, we used a simple two-spheres model and a three-dimensional Laplace solver to simulate the electric field and the tunneling current in the oxide region. Our results show that both quantities are strong functions of roughness spatial wavelength, associated amplitude, and oxide thickness. We found that RMS roughness itself cannot fully characterize surface roughness and that roughness has a larger effect for thicker oxide in terms of surface electric field and tunneling behavior.

scholarly journals Simulation of Thermal and Electric Field Distribution in Packaged Sausages Heated in a Stationary Versus a Rotating Microwave Oven

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1622
Author(s):  
Wipawee Tepnatim ◽  
Witchuda Daud ◽  
Pitiya Kamonpatana
Keyword(s):  
Temperature Distribution ◽  
Electric Field ◽  
Three Dimensional ◽  
Development Stage ◽  
Microwave Oven ◽  
Computational Time ◽  
Plastic Package ◽  
Heating Uniformity ◽  
The Cost ◽  
Good Agreement

The microwave oven has become a standard appliance to reheat or cook meals in households and convenience stores. However, the main problem of microwave heating is the non-uniform temperature distribution, which may affect food quality and health safety. A three-dimensional mathematical model was developed to simulate the temperature distribution of four ready-to-eat sausages in a plastic package in a stationary versus a rotating microwave oven, and the model was validated experimentally. COMSOL software was applied to predict sausage temperatures at different orientations for the stationary microwave model, whereas COMSOL and COMSOL in combination with MATLAB software were used for a rotating microwave model. A sausage orientation at 135° with the waveguide was similar to that using the rotating microwave model regarding uniform thermal and electric field distributions. Both rotating models provided good agreement between the predicted and actual values and had greater precision than the stationary model. In addition, the computational time using COMSOL in combination with MATLAB was reduced by 60% compared to COMSOL alone. Consequently, the models could assist food producers and associations in designing packaging materials to prevent leakage of the packaging compound, developing new products and applications to improve product heating uniformity, and reducing the cost and time of the research and development stage.

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