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.

Dynamic Reduced Electrothermal Model for Integrated Power Electronics Modules (IPEM)

2004 ◽  
Vol 126 (4) ◽  
pp. 477-490 ◽  
Author(s):  
M. Herna´ndez-Mora ◽  
J. E. Gonza´lez ◽  
M. Ve´lez-Reyes ◽  
J. M. Ortiz-Rodrı´guez ◽  
Y. Pang ◽  
...  
Keyword(s):  
Power Electronics ◽  
Thermal Model ◽  
High Speed ◽  
Three Dimensional ◽  
Thermal Response ◽  
Software Tool ◽  
Computational Time ◽  
Highly Nonlinear ◽  
Numerical Formulation ◽  
Good Agreement

Background: This paper presents a reduced mathematical model using a practical numerical formulation of the thermal behavior of an integrated power electronics module (IPEM). This model is based on the expanded lumped thermal capacitance method (LTCM), in which the number of variables involved in the analysis of heat transfer is reduced only to time. Method of Approach: By applying the LTCM, a simple, nonspatial, but highly nonlinear model is obtained for the case of the IPEM Generation II. Steady and transient results of the model are validated against results from a three-dimensional, transient thermal analysis software tool, FLOTHERM™ 3.1. The electrothermal coupling was obtained by implementing the reduced-order thermal model into the SABER™ circuit simulator. Two experimental setups, for low- and high-speed thermal responses, were developed and used to calibrate the reduced model with actual data. Results: The comparison of the LTCM model implemented in a Generation II IPEM with FLOTHERM 3.1 results compared very favorably in terms of accuracy and efficiency, reducing the computational time significantly. Additional validations of the reduced thermal model were made using experiment data for the low-speed thermal response at different constant powers, and good agreement was demonstrated in all cases. A comparison between SABER™ simulations, which incorporated the proposed LTCM, and the fast thermal experimental response results is also presented to validate the dynamic electrothermal model response, and excellent agreement was found for this case. Conclusions: The good agreement found for all three cases presented, the three-dimensional, transient numerical formulation, and the low- and high-speed experimental data indicates that reduced electrothermal models are an excellent alterative for design methodologies of new generations of IPEMs.

Reliability of SnAgCu Alloys for CMOS Image Sensor QFN Package under Thermal Cycling Loading

2008 ◽  
Vol 594 ◽  
pp. 175-180
Author(s):  
Hsiang Chen Hsu ◽  
Hui Yu Lee ◽  
Wen Lo Shieh
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Element Model ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Computational Time ◽  
Mesh Density ◽  
Good Agreement

A three-dimensional finite element model of CMOS image sensor QFN packaging using ANSYS codes is developed to investigate the solder joint reliability under thermal cycle test. The predicted thermal-induced displacements were found to be very good agreement with the Moiré interferometer experimental in-plane deformations. The developed finite element model is then applied to predict fatigue life of Sn4.0Ag0.5Cu, Sn3.5Ag0.5Cu and Sn3.9Ag0.6Cu alloys based on JEDEC standard JESD22-A104. In order to save computational time and produce satisfactory results in the region of interest, an independent more finely meshed so-called submodel scheme based on cut-boundary displacement method is generated. The mesh density for different area ratio of refinery/coarse model was verified and the results were found to be good agreement with previous researches. The modified Coffin-Manson equation and strain energy density based equation are applied to evaluate the reliability of SnAgCu alloys. A series of comprehensive parametric studies were conducted in this paper.

Application of Landweber Method for Three-Dimensional Temperature Field Reconstruction Based on the Light-Field Imaging Technique

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Xing Huang ◽  
Hong Qi ◽  
Xiao-Luo Zhang ◽  
Ya-Tao Ren ◽  
Li-Ming Ruan ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Light Field ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Computational Time ◽  
Reconstruction Technique ◽  
Absorbing Media ◽  
Light Field Imaging ◽  
Landweber Method ◽  
Field Imaging

Combined with the light-field imaging technique, the Landweber method is applied to the reconstruction of three-dimensional (3D) temperature distribution in absorbing media theoretically and experimentally. In the theoretical research, simulated exit radiation intensities on the boundary of absorbing media according to the computing model of light field are employed as inputs for inverse analysis. Compared with the commonly used iterative methods, i.e., the least-square QR decomposition method and algebraic reconstruction technique (ART), the Landweber method can produce reconstruction results with better quality and less computational time. Based on the numerical study, an experimental investigation is conducted to validate the suitability of the proposed method. The temperature distribution of the ethylene diffusion flame is reconstructed by using the Landweber method from the flame image captured by a light-field camera. Good agreement was found between the reconstructed temperature distribution and the measured temperature data obtained by a thermocouple. All the experimental results demonstrate that the temperature distribution of ethylene flame can be reconstructed reasonably by using the Landweber method combined with the light-field imaging technique, which is proven to have potential for the use in noncontract measurement of temperature distribution in practical engineering applications.

scholarly journals 3D modeling of a superconducting dynamo-type flux pump

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Asef Ghabeli ◽  
Enric Pardo ◽  
Milan Kapolka
Keyword(s):  
Electric Field ◽  
3D Model ◽  
Precise Measurement ◽  
Electric Field Distribution ◽  
Three Dimensional ◽  
Working Mechanism ◽  
Voltage Generation ◽  
The Impact ◽  
Good Agreement ◽  
Flux Pump

AbstractHigh temperature superconducting (HTS) dynamos are promising devices that can inject large DC currents into the winding of superconducting machines or magnets in a contactless way. Thanks to this, troublesome brushes in HTS machines or bulky currents leads with high thermal losses will be no longer required. The working mechanism of HTS dynamo has been controversial during the recent years and several explanations and models have been proposed to elucidate its performance. In this paper, we present the first three-dimensional (3D) model of an HTS flux pump, which has good agreement with experiments. This model can be beneficial to clarify the mechanism of the dynamo and pinpoint its unnoticed characteristics. Employing this model, we delved into the screening current and electric field distribution across the tape surface in several crucial time steps. This is important, since the overcritical screening current has been shown to be the reason for flux pumping. In addition, we analyzed the impact of both components of electric field and screening current on voltage generation, which was not possible in previous 2D models. We also explored the necessary distance of voltage taps at different airgaps for precise measurement of the voltage across the tape in the dynamo.

scholarly journals A Computational Model for Real-Time Calculation of Electric Field due to Transcranial Magnetic Stimulation in Clinics

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Alessandra Paffi ◽  
Francesca Camera ◽  
Filippo Carducci ◽  
Gianluigi Rubino ◽  
Paolo Tampieri ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Electric Field ◽  
Real Time ◽  
Magnetic Stimulation ◽  
Brain Regions ◽  
Computational Time ◽  
Time Calculation ◽  
Magnetic Resonance Imaging Mri ◽  
Time Evaluation ◽  
Good Agreement

The aim of this paper is to propose an approach for an accurate and fast (real-time) computation of the electric field induced inside the whole brain volume during a transcranial magnetic stimulation (TMS) procedure. The numerical solution implements the admittance method for a discretized realistic brain model derived from Magnetic Resonance Imaging (MRI). Results are in a good agreement with those obtained using commercial codes and require much less computational time. An integration of the developed code with neuronavigation tools will permit real-time evaluation of the stimulated brain regions during the TMS delivery, thus improving the efficacy of clinical applications.

scholarly journals Solar wind dynamics around a comet

2018 ◽  
Vol 620 ◽  
pp. A35 ◽  
Author(s):  
E. Behar ◽  
B. Tabone ◽  
M. Saillenfest ◽  
P. Henri ◽  
J. Deca ◽  
...  
Keyword(s):  
Solar Wind ◽  
Electric Field ◽  
Three Dimensional ◽  
Solar Wind Proton ◽  
In Situ Data ◽  
Collisionless Plasmas ◽  
Rosetta Mission ◽  
Proton Dynamics ◽  
Good Agreement

Aims. We aim at analytically modelling the solar wind proton trajectories during their interaction with a partially ionised cometary atmosphere, not in terms of bulk properties of the flow but in terms of single particle dynamics. Methods. We first derive a generalised gyromotion, in which the electric field is reduced to its motional component. Steady-state is assumed, and simplified models of the cometary density and of the electron fluid are used to express the force experienced by individual solar wind protons during the interaction. Results. A three-dimensional (3D) analytical expression of the gyration of two interacting plasma beams is obtained. Applying it to a comet case, the force on protons is always perpendicular to their velocity and has an amplitude proportional to 1/r2. The solar wind deflection is obtained at any point in space. The resulting picture presents a caustic of intersecting trajectories, and a circular region is found that is completely free of particles. The particles do not lose any kinetic energy and this absence of deceleration, together with the solar wind deflection pattern and the presence of a solar wind ion cavity, is in good agreement with the general results of the Rosetta mission. Conclusions. The qualitative match between the model and the in situ data highlights how dominant the motional electric field is throughout most of the interaction region for the solar wind proton dynamics. The model provides a simple general kinetic description of how momentum is transferred between these two collisionless plasmas. It also shows the potential of this semi-analytical model for a systematic quantitative comparison to the data.

On the Field of Temperatures in Lubricating Films

1967 ◽  
Vol 89 (4) ◽  
pp. 483-491 ◽  
Author(s):  
N. Tipei ◽  
Al. Nica
Keyword(s):  
Temperature Distribution ◽  
Pressure Distribution ◽  
Energy Equation ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Dimensional Case ◽  
Experimental Measurements ◽  
Lubricating Film ◽  
Good Agreement

The temperature distribution in the lubricating film of journal bearings for the three-dimensional case is obtained by using the results already known regarding the pressure distribution in the film and by integrating the energy equation. Relations for the divergent and convergent zones of the bearing are established by taking into account the viscosity and the side leakage; the distribution of the temperature along the bearing width is also considered. Comparisons between the theoretical values and experimental measurements are also performed, resulting in good agreement.

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.

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