Numerical Simulation of Microwave Heating for Soot Oxidation

2014 ◽  
Vol 564 ◽  
pp. 256-262 ◽  
Author(s):  
Haitham B. Al-Wakeel ◽  
Z.A. Abdul Karim ◽  
Hussain Hamoud Al-Kayiem
Keyword(s):  
Electric Field ◽  
Microwave Heating ◽  
Penetration Depth ◽  
Soot Oxidation ◽  
Small Samples ◽  
Front Face ◽  
Maximum Temperature ◽  
Ignition Point ◽  
Transient Thermal ◽  
The Mathematical Model

This paper presents the simulation of microwave heating by coupling high frequency electromagnetic with transient heat transfer using finite element method edge base of ANSYS software. Helmholtz equation of electric field has been formulated from Maxwell equations to predict electric field and the mathematical model of transient thermal analysis was included. Three cases have been examined numerically to investigate electric field, dissipated heat, temperature distribution and weight loss of soot at operation frequency 2.45 GHz. The simulation results showed that heat is generated from inside to outside of soot. The temperature at penetration depth increased till ignition point and after further heating, maximum temperature was attained, followed by temperature decreases due to mass transport. Maximum electric field was found to be located on the front face for the small samples with dimensions less than penetration depth. The predicted results have been compared with experimental results which show the validity of the simulation.

scholarly journals Improving Microwave Heating using Polysaccharides as Thickeners

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S342-S345
Author(s):  
L. M Guardeño ◽  
M. Hernández-Carrión ◽  
J. M Catala-Civera ◽  
P. Plaza ◽  
I. Pérez-Munuera ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Electric Field ◽  
Microwave Heating ◽  
Penetration Depth ◽  
Loss Factor ◽  
The Other ◽  
Model Systems ◽  
Starch Concentration ◽  
Modified Starches ◽  
Kappa Carrageenan

The aim of this work was to improve microwave heating in white sauces using different polysaccharides in their formulation; &iota;-, &lambda;- and &kappa-carrageenan and native and modified starches were used as thickeners. Five model systems were prepared, each one with a different polysaccharide, salt, and water. Dielectric loss factor (&epsilon;'') was measured and penetration depth of the electric field was calculated at 20 and 40°C at 2450 GHz. The results showed that &epsilon;'' increased significantly (<I>P</I> < 0.05) when temperature rose in all the model systems. Moreover, &epsilon;'' decreased significantly (<I>P</I> < 0.05) when the polysaccharide concentration rose in the systems elaborated with starch (both native and modified). The penetration depth increased significantly at 40°C when native starch concentration rose. Not significant differences due to the thickener concentration were found in the depth penetration values in the other model systems, both at 20 and 40°C.

Numerical Simulation of High Frequency Electromagnetic Wave in Microwave Cavity for Soot Oxidation

2013 ◽  
Vol 459 ◽  
pp. 310-318 ◽  
Author(s):  
Haitham B. Al-Wakeel ◽  
Zainal Ambri Abdul Karim ◽  
Hussain Hamoud Al-Kayiem ◽  
Hasan Fawad
Keyword(s):  
Numerical Simulation ◽  
Electric Field ◽  
Penetration Depth ◽  
Field Distribution ◽  
High Frequency ◽  
Electric Field Distribution ◽  
Soot Oxidation ◽  
Microwave Cavity ◽  
Field Pattern ◽  
The Impact

Soot oxidation temperature by high frequency electromagnetic energy was proposed using numerical simulation by combining electromagnetic with transient thermal analyses. Equation of electric field distribution in a microwave cavity with perfect electric conductor surfaces and TE10 mode is formulated from Helmholtz equation. The dissipated heat distribution is calculated from the electric field distribution. Six study cases for electric field and dissipated heat distributions were implemented by using ANSYS software based on finite element method. The impact of dielectric sample properties, position, size and shape inside the microwave cavity were predicted. The results from the simulation of electric field and dissipated heat were compared with available data in literature and showed the validity of the analysis. It was found that the electric field forming hot spots at penetration depth and front corners of the soot sample and penetration depth is equal to 12mm but equal to 0 for samples with dimensions less than penetration depth. Dissipated heat pattern depend on electric field pattern and dielectric properties.

Study on stability of electric field in multimode microwave heating cavity

2016 ◽  
Vol 50 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Z.-M. Tang ◽  
K.-M. Huang ◽  
Y.-H. Liao ◽  
T. Hong ◽  
H.-C. Zhu
Keyword(s):  
Electric Field ◽  
Microwave Heating

scholarly journals Research on Electromagnetic Sensitivity Properties of Sodium Chloride during Microwave Heating

2020 ◽  
Vol 39 (1) ◽  
pp. 54-62
Author(s):  
Hua Chen ◽  
Junjiang Chen ◽  
Weijun Wang ◽  
Huan Lin
Keyword(s):  
Sodium Chloride ◽  
Electric Field ◽  
Water Content ◽  
Heating Rate ◽  
Microwave Heating ◽  
Resonant Cavity ◽  
Relative Dielectric Constant ◽  
Heating System ◽  
Heating Process ◽  
Heating Efficiency

AbstractThe multimode resonant cavity is the most common cavity. The material often shows on selective heating performance during the heating process due to the effect of microwave heating having a closely relationship with the electromagnetism parameters. This paper is based on finite difference time domain method (FDTD) to establish the electromagnetic-thermal model. The electromagnetic sensitivity property parameters of sodium chloride including relative dielectric constant, loss angle tangent and water content of sodium chloride is studied during the heating and drying process. The heating rate and the electric field distribution of sodium chloride, at the different water content, were simulated with the electromagnetic characteristic parameters changing. The results show that with the electromagnetic sensitivity property parameters varying, the electric field strength, heating rate and steady-state temperature of the heating material will all have a variety in the cavity. Some measures are proposed to improve the heating efficiency and ensure the stability of the microwave heating system in the industrial application.

Synthesis of YFeO3-δ and LaFeO3-δ Perovskites with High Catalytic Activity in Carbon Oxidation Reactions

2021 ◽  
Vol 316 ◽  
pp. 105-109
Author(s):  
Evgeny A. Kirichenko ◽  
Pavel G. Chigrin ◽  
Anton A. Gnidenko
Keyword(s):  
Oxidation Mechanism ◽  
Soot Oxidation ◽  
Complex Oxide ◽  
Maximum Temperature ◽  
High Catalytic Activity ◽  
Carbon Oxidation ◽  
Oxidation Reactions ◽  
Oxide Systems ◽  
Reduction Of Metal Oxides ◽  
Catalytic Reaction Mechanism

YFeO3-δ (δ = 0.26) and LaFeO3-δ (δ = 0.5) perovskites with a high specific surface and oxygen non-stoichiometry was firstly synthesized by pyrolysis of polymer-salt compositions. It was shown that the catalytic oxidation of carbon in the presence of these complex oxide systems proceeds in the range of 400 - 700 °С, with a maximum temperature at 556 °С for YFeO3-δ; and 380 - 620 °С ,with a maximum temperature at 501 °С for LaFeO3-δ, in one-stage mode for both. By means of thermal analysis and diffractometry, it was shown that there is no contribution to the soot oxidation mechanism by cyclic perovskite surface transformations, due to the reduction of metal oxides by the soot and their subsequent reoxidation. It has been established that the basis of the catalytic reaction mechanism for both perovskites is the presence of oxygen vacancies on the surface of complex oxides.

scholarly journals Optimizing electro-thermo Helds for soot oxidation using microwave heating and metal

2015 ◽  
Vol 78 ◽  
pp. 012018 ◽  
Author(s):  
Haitham B Al-Wakeel ◽  
Z A Abdul Karim ◽  
Hussain H Al-Kayiem
Keyword(s):  
Microwave Heating ◽  
Soot Oxidation

Investigation on the ballistic performance of rubber-aluminum (AA7075-T651) laminated plates reinforced with borosilicate glass balls

2021 ◽  
pp. 146442072110444
Author(s):  
Hasan Kasım
Keyword(s):  
Penetration Depth ◽  
Borosilicate Glass ◽  
Plate Thickness ◽  
High Strength ◽  
Laminated Plates ◽  
Front Face ◽  
Ballistic Performance ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
Aluminum Plates

In this study, the ballistic behavior of protective armor plates (PaP) obtained by curing between high structural strength AA7075-T651 aluminum plates by reinforcing with glass balls of two different rubber mixtures whose damping properties were developed with carbon nanotube and glass bubbles fillers were investigated. A total of six PaPs at 27, 30, and 35 mm heights were prepared using two different matrix damping rubbers. High-strength liner rubber used in air bellows is vulcanized on the front and back surfaces of PaPs. Between the PaPs, Ø15.875 and Ø6.747 mm, borosilicate glass balls were placed in a particular arrangement that coincides with the middle of the matrix rubber and does not have any gaps. Liner rubber cured on the front face has managed to hold the energy by forming a layer like clothing around the bullet cores. Glass balls between PAPs play an essential role in the energy absorption of GB-filled mixtures. In contrast, in MWCNT-filled mixtures, they act as a second damping element. The ballistic performance of PAPs prepared with multiwalled carbon nanotubes was determined to be better than those prepared with Glass Bubbles. Thanks to the superior mechanical properties and high aspect ratio of MWCNTs, the penetration and swelling heights of the matrix damping rubbers prepared to have excellent results compared to glass bubbles. With the increase in the thickness of the PaPs prepared with MWCNTs, the deformation effect of the penetration depth and bulging height created by the bullet on the anterior and posterior surfaces decreased. As the thickness of PaP increased from 27 mm to 35 mm, penetration depth decreased by 38%, and bulging height reduced by 35%. The amount of penetration and swelling increased in PaPs using rubber filled with glass bubbles. As the plate thickness increased, the damping feature decreased and the glass balls were activated, and the bullet was stopped.

Efficient Thermal Analysis of Lab-Grown Diamond Heat Spreaders

2021 ◽  
Author(s):  
Zihao Yuan ◽  
Tao Zhang ◽  
Jeroen Van Duren ◽  
Ayse K. Coskun
Keyword(s):  
Steady State ◽  
Real World ◽  
High Performance ◽  
Silicon Layer ◽  
Maximum Temperature ◽  
Cooling Performance ◽  
Thermal Models ◽  
Heat Spreaders ◽  
Transient Simulations ◽  
Transient Thermal

Abstract Lab-grown diamond heat spreaders are becoming attractive solutions compared to traditional copper heat spreaders due to their high thermal conductivity, the ability to directly bond them on silicon, and allow for an ultra-thin silicon layer. Researchers have developed various thermal models and prototypes of lab-grown diamond heat spreaders to evaluate their cooling performance and heat spreading ability. The majority of existing thermal models are built using finite-element method (FEM) based simulators such as COMSOL and ANSYS. However, such commercial simulators are computationally expensive and lead to long solution times along with large memory requirements. These limitations make commercial simulators unsuitable for evaluating numerous design alternatives or runtime scenarios for real-world high-performance processors. Because of this modeling challenge, none of the existing works have evaluated the thermal behavior of lab-grown diamond heat spreaders on real-world high-performance processors running realistic application benchmarks. Recently, we have developed a parallel compact thermal simulator, PACT, that is able to carry out fast and accurate steady-state and transient thermal simulations and can be extended to support emerging integration and cooling technologies. In this paper, we use PACT to evaluate the steady-state and transient cooling performance of lab-grown diamond heat spreaders against traditional copper heat spreaders on various real-world high-performance processors (e.g., Intel i7 6950X, IBM Power9, and PicoSoC). By using PACT with architectural performance and power simulators such as Sniper and McPAT, we are able to run transient simulations with realistic benchmarks. Simulation results show that lab-grown diamond heat spreaders achieve maximum temperature and thermal gradient reductions of up to 26.73 °C and 13.75 °C when compared to traditional copper heat spreaders, respectively. The maximum steady-state and transient simulation times of PACT for the real-world high-performance chips and realistic applications used in our experiments are 259 s and 22 min, respectively.

scholarly journals The multiplicity of steady-state solutions arising from microwave heating. I. Infinite Biot number and small penetration depth

2001 ◽  
Vol 43 (1) ◽  
pp. 87-103 ◽  
Author(s):  
M. I. Nelson ◽  
G. C. Wake ◽  
X. D. Chen ◽  
E. Balakrishnan
Keyword(s):  
Steady State ◽  
Microwave Heating ◽  
Penetration Depth ◽  
Biot Number ◽  
Microwave Power ◽  
Phase Plane ◽  
Solid Materials ◽  
Temperature Function ◽  
Class A ◽  
Steady State Solutions

AbstractMicrowave heating of porous solid materials has received considerable attention in recent years because of its widespread use in industry. In this study, the microwave power absorption term is modelled as the product of an exponential temperature function with function that decays exponentially with distance. The latter describes the penetration of material by the microwaves.We investigate the phenomena of multiplicity in class A geometries, paying particular attention to how the penetration function affects the behaviour of the system. We explain why the phase-plane techniques which have been used in the case when the penetration term is constant do not extend to non-constant penetration.

scholarly journals Microwave Heating Characteristics of Emulsified Asphalt Repair Materials Incorporated with Steel Slag

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yongfeng Wei ◽  
Jinyang Huo ◽  
Zhenjun Wang ◽  
Jiangtao Gao
Keyword(s):  
Microwave Heating ◽  
Steel Slag ◽  
Asphalt Mixture ◽  
Maximum Temperature ◽  
Interface Area ◽  
Heating Effects ◽  
Repair Materials ◽  
Three Stages ◽  
Emulsified Asphalt ◽  
Heating Technology

Emulsified asphalt needs to be cured for a certain age after demulsification to produce strength, which seriously affects the traffic opening time. In this work, microwave heating technology was applied for emulsified asphalt repair materials. Steel slag with high microwave activity was adopted to improve the performance of emulsified asphalt repair materials by microwave heating. Effects of steel slag sizes and contents on the heating rate, temperature distribution, and thermal performance of emulsified asphalt repair materials were analyzed by close microwave heating, open microwave heating, and repair simulation tests. Results show that the temperature of emulsified asphalt repair materials presents three different heating stages under microwave irradiation. The “critical point of phase transition” in the three stages is gradually advanced with the increase in steel slag content. The core temperature and maximum temperature of emulsified asphalt repair materials with different steel slag sizes are basically the same; however, the heat distribution of emulsified asphalt repair materials is significantly different. In contrast to conventional asphalt mixture, there exists a smaller temperature difference. The temperature of repairing materials can reach above 80°C. The interface area can form an embedded interface structure. Incorporation of steel slag and adoption of microwave heating are effective to improve the performance of emulsified asphalt repair materials.

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