scholarly journals Sweep Frequency Heating based on Injection Locked Magnetron

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 341 ◽  
Author(s):  
Fengming Yang ◽  
Wenwen Wang ◽  
Bo Yan ◽  
Tao Hong ◽  
Yang Yang ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Electromagnetic Waves ◽  
Calculation Model ◽  
Sweep Frequency ◽  
Frequency Locking ◽  
Injection Frequency ◽  
Heating Uniformity ◽  
Simulation Results ◽  
Low Efficiency ◽  
Frequency Heating

Conventional microwave heating has serious problems such as non-uniform heating and low efficiency. A novel magnetron microwave sweep frequency heating method is proposed to improve microwave heating uniformity. In this method, the frequency-sweeping signal is injected into the magnetron by the injection frequency-locking technique, and the microwave sweep frequency heating of the magnetron is realized. In this paper, a complicated injection frequency locking system is given and analyzed and a multiphysics calculation model based on the finite element method for electromagnetic waves and heat transfer is established. The calculation of microwave sweep frequency heating is realized by the combination of COMSOL and MATLAB. The results show that the sweep frequency heating has an obvious superiority. An experiment is carried out to verify the simulation results. The simulation results are in agreement with the experimental data. Moreover, the effect of sweep bandwidth and sweep interval on heating uniformity is discussed.

scholarly journals Impact of Filled Materials on the Heating Uniformity and Safety of Microwave Heating Solid Stack Materials

Processes ◽  
2018 ◽  
Vol 6 (11) ◽  
pp. 220 ◽  
Author(s):  
Jing Wang ◽  
Tao Hong ◽  
Tian Xie ◽  
Fan Yang ◽  
Yusong Hu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Electric Field ◽  
Microwave Heating ◽  
Imaginary Part ◽  
Relative Permittivity ◽  
Maximum Modulus ◽  
The Finite Element Method ◽  
Heating Uniformity ◽  
Simulation Results ◽  
Uneven Heating

Microwave heating of solid stack materials is common but bothered by problems of uneven heating and electric discharge phenomena. In this paper, a method introducing fluid materials with different relative permittivity is proposed to improve the heating uniformity and safety of solid stack materials. Simulations have been computed based on the finite element method (FEM) and validated by experiments. Simulation results show that the introducing of fluid materials with proper relative permittivity does improve the heating uniformity and safety. Fluid materials with the larger real part of relative permittivity could obviously lower the maximum modulus value of the electric field for about 23 times, and will lower the coefficient of variation (COV) in general, although in small ranges that it has fluctuated. Fluid materials with the larger imaginary part of relative permittivity, in a range from 0 to 0.3, can make a more efficient heating and it could lower the maximum modulus value of the electric field by 34 to 55% on the whole studied range. However, the larger imaginary part of relative permittivity will cause worse heating uniformity as the COV rises by 246.9% in the same process. The computed results are discussed and methods to reach uniform and safe heating through introducing fluid materials with proper relative permittivity are proposed.

scholarly journals Macro Modeling of V-Shaped Electro-Thermal MEMS Actuator with Human Error Factor

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 622
Author(s):  
Dongpeng Zhang ◽  
Anjiang Cai ◽  
Yulong Zhao ◽  
Tengjiang Hu
Keyword(s):  
Neural Network ◽  
Simulation Model ◽  
Bp Neural Network ◽  
Human Error ◽  
Calculation Model ◽  
Fuzzy Mathematics ◽  
Ansys Simulation ◽  
Macro Modeling ◽  
Error Factor ◽  
Simulation Results

The V-shaped electro-thermal MEMS actuator model, with the human error factor taken into account, is presented in this paper through the cascading ANSYS simulation model and the Fuzzy mathematics calculation model. The Fuzzy mathematics calculation model introduces the human error factor into the MEMS actuator model by using the BP neural network, which effectively reduces the error between ANSYS simulation results and experimental results to less than 1%. Meanwhile, the V-shaped electro-thermal MEMS actuator model, with the human error factor included, will become more accurate as the database of the V-shaped electro-thermal actuator model grows.

scholarly journals Influence of Selected Model Parameters on the Electromagnetic Levitation Melting Efficiency

2021 ◽  
Vol 11 (9) ◽  
pp. 3827
Author(s):  
Blazej Nycz ◽  
Lukasz Malinski ◽  
Roman Przylucki
Keyword(s):  
Electromagnetic Levitation ◽  
Optimization Methods ◽  
Calculation Model ◽  
Model Parameters ◽  
Starting Point ◽  
Low Efficiency ◽  
The Relationship ◽  
Reactive Metals ◽  
Electromagnetic Levitation Melting ◽  
Metal Melting

The article presents the results of multivariate calculations for the levitation metal melting system. The research had two main goals. The first goal of the multivariate calculations was to find the relationship between the basic electrical and geometric parameters of the selected calculation model and the maximum electromagnetic buoyancy force and the maximum power dissipated in the charge. The second goal was to find quasi-optimal conditions for levitation. The choice of the model with the highest melting efficiency is very important because electromagnetic levitation is essentially a low-efficiency process. Despite the low efficiency of this method, it is worth dealing with it because is one of the few methods that allow melting and obtaining alloys of refractory reactive metals. The research was limited to the analysis of the electromagnetic field modeled three-dimensionally. From among of 245 variants considered in the article, the most promising one was selected characterized by the highest efficiency. This variant will be a starting point for further work with the use of optimization methods.

scholarly journals Numerical modeling of microwave heating

2010 ◽  
Vol 42 (1) ◽  
pp. 99-124 ◽  
Author(s):  
A.K. Shukla ◽  
A. Mondal ◽  
A. Upadhyaya
Keyword(s):  
Thermal Conductivity ◽  
Numerical Modeling ◽  
Temperature Distribution ◽  
Microwave Heating ◽  
Two Dimensional ◽  
Conventional Furnace ◽  
Microwave Furnace ◽  
Simulation Results ◽  
Heating Behavior ◽  
Cylindrical Samples

The present study compares the temperature distribution within cylindrical samples heated in microwave furnace with those achieved in radiatively-heated (conventional) furnace. Using a two-dimensional finite difference approach the thermal profiles were simulated for cylinders of varying radii (0.65, 6.5, and 65 cm) and physical properties. The influence of susceptor-assisted microwave heating was also modeled for the same. The simulation results reveal differences in the heating behavior of samples in microwaves. The efficacy of microwave heating depends on the sample size and its thermal conductivity.

scholarly journals A Small-Divergence-Angle Orbital Angular Momentum Metasurface Antenna

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianchun Xu ◽  
Ke Bi ◽  
Ru Zhang ◽  
Yanan Hao ◽  
Chuwen Lan ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Electromagnetic Waves ◽  
Divergence Angle ◽  
Compact Structure ◽  
Phase Gradient ◽  
Practical Applications ◽  
Circular Arrangement ◽  
Low Efficiency ◽  
Theoretical Analyses

Electromagnetic waves carrying an orbital angular momentum (OAM) are of great interest. However, most OAM antennas present disadvantages such as a complicated structure, low efficiency, and large divergence angle, which prevents their practical applications. So far, there are few papers and research focuses on the problem of the divergence angle. Herein, a metasurface antenna is proposed to obtain the OAM beams with a small divergence angle. The circular arrangement and phase gradient were used to simplify the structure of the metasurface and obtain the small divergence angle, respectively. The proposed metasurface antenna presents a high transmission coefficient and effectively decreases the divergence angle of the OAM beam. All the theoretical analyses and derivation calculations were validated by both simulations and experiments. This compact structure paves the way to generate OAM beams with a small divergence angle.

Electromagnetic waves transmission performance of alumina refractory ceramics in 2.45 GHz microwave heating

2019 ◽  
Vol 45 (17) ◽  
pp. 23493-23500 ◽  
Author(s):  
Xiaobiao Shang ◽  
Di Zhai ◽  
Fucheng Zhang ◽  
Cong Wei ◽  
Junruo Chen ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Electromagnetic Waves ◽  
Transmission Performance ◽  
Alumina Refractory ◽  
Refractory Ceramics

scholarly journals Dynamic analysis of material motion using MATLAB/Simulation environment and test verification

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095780
Author(s):  
Mei Fang ◽  
Zhihong Yu ◽  
Wenjie Zhang
Keyword(s):  
Dynamic Analysis ◽  
Structural Design ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Maximum Relative Error ◽  
Matlab Simulation ◽  
Simulation Results ◽  
Low Efficiency ◽  
Test Verification ◽  
The Mathematical Model

Throwing device is an important factor that directly affects the performance of chaff cutter. In this work, the dynamic analysis linked with the problem of low efficiency and residue blockage of disc knife chaff cutter is executed. Based on this perspective, the mathematical model, simulation, and testing of the material movement have been carried out. Simulations are performed in MATLAB/Simulink environment. An anemometer records the airflow velocity, which provides data for simulation analysis. The simulation results showed that during the movement along the blade, the material first performs deceleration and then accelerates; in other stages, only deceleration. And finally calculated the throwing distance. To support the presented simulations, an experimental study is conducted. The experimental results are compared with simulation results, the maximum relative error between the simulated value and the experimental value is 9.42%, which verified the correctness of the model. This research provides a theoretical basis for the structural design, parameter optimization, and matching of the chaff cutter.

Dielectric properties, heating rate, and heating uniformity of various seasoning spices and their mixtures with radio frequency heating

2018 ◽  
Vol 228 ◽  
pp. 128-141 ◽  
Author(s):  
Samet Ozturk ◽  
Fanbin Kong ◽  
Rakesh K. Singh ◽  
Jesse Daniel Kuzy ◽  
Changying Li ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Radio Frequency ◽  
Heating Rate ◽  
Radio Frequency Heating ◽  
Heating Uniformity ◽  
Frequency Heating
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