scholarly journals Electric Field Interaction with Hydrocarbon Flames

2018 ◽  
Vol 63 (5) ◽  
pp. 402
Author(s):  
S. G. Orlovskaya ◽  
M. S. Skoropado ◽  
F. F. Karimova ◽  
V. Ya. Chernyak ◽  
L. Yu. Vergun
Keyword(s):  
Melting Point ◽  
Field Strength ◽  
Electric Field ◽  
Fossil Fuels ◽  
Melting Process ◽  
Melting Rate ◽  
Melting Time ◽  
Field Interaction ◽  
Hydrocarbon Flames ◽  
Dc Electric Field

The problem of electric-field-assisted combustion for low-melting point hydrocarbons (paraffin wax, n-alkanes) attracts the attention of scientists in relation to the development of paraffin-based propellants. Our study is aimed at the detailed investigation of the dc electric field interaction with the flame of octadecane droplet. We have studied the melting and combustion of alkane particles in the electric field ranging from 33 kV/m to 117 kV/m. It is found that the melting rate decreases distinctly starting with the electric field strength E ∼ 80 kV/m. This effect is more pronounced at high gas temperatures (Ste >1), when the melting time is about a few seconds. So, the melting process slows down in the dc electric field. At the same time, the burning rate constant rises by more than 10 percents. The obtained results can be used to develop efficient and clean technologies of fossil fuels combustion.

Electroviscoelastic Properties in ER Gel of Disperse System under DC Electric Field

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2433-2439 ◽  
Author(s):  
R. HANAOKA ◽  
S. TAKATA ◽  
H. FUJITA ◽  
T. FUKAMI ◽  
K. SAKURAI ◽  
...  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Disperse System ◽  
Fine Particles ◽  
Silicone Oil ◽  
Dynamic Properties ◽  
Low Frequencies ◽  
Hydrosilylation Reaction ◽  
Microscopical Method ◽  
Dc Electric Field

The silicone oil-based electrorheological (ER) gel containing the non-aqueous fine particles was newly created in the present study. After these particles were dispersed at 30wt.% in the dimethylsilicone oil, the ER gel was produced by the hydrosilylation reaction in the mixture of the modified silicone oil. The reaction could considerably be promoted by heating at 90°C. The behavior of particles in the ER gel was observed by a microscopical method. When an electric field was applied to the ER gel, the gap between the electrodes was bridged by the chains of particles arranged in the direction of the electric field. The dynamic properties of the ER gel were also examined under the applied dc electric field up to 2kV/mm using the oscillating rheometer with the low frequencies of 1Hz or less. Consequently, it is shown that the electroviscoelastic effect of the gel can be controlled by the electric field strength.

Remelting and Addition of Alloy Components

2021 ◽  
pp. 405-449
Author(s):  
Thorvald Abel Engh ◽  
Geoffrey K. Sigworth ◽  
Anne Kvithyld
Keyword(s):  
Melting Point ◽  
Numerical Model ◽  
Melting Process ◽  
Class Ii ◽  
Melting Rate ◽  
Intermetallic Phases ◽  
Class I ◽  
Melt Temperature ◽  
Continuous Feeding ◽  
Conservation Model

This chapter discusses our scientific understanding of alloying. Class I alloy additions have a melting point lower than the bulk melt temperature, whereas class II additions have a melting point higher than the bulk melt temperature. This means that magnesium is a class I element when added to aluminium, and silicon and manganese are class II alloy additions. An energy conservation model for melting is presented and compared to measurements. A numerical model is presented for continuous feeding and melting of aluminium plates into aluminium melt. For class II alloy additions it is shown from the literature that the melting rate can be strongly affected by the formation of intermetallic phases during the melting process. Therefore, it is virtually impossible to put up a general model for the melting of these types of alloying elements. Safety regarding alloying operations is also addressed.

Bubble Formation in a DC Electric Field

2008 ◽  
Author(s):  
Feng Chen ◽  
Yaozu Song ◽  
Yao Peng
Keyword(s):  
Aspect Ratio ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Bubble Growth ◽  
Growth Process ◽  
Major Axis ◽  
Minor Axis ◽  
Electric Stress ◽  
Dc Electric Field

The effect of a DC electric field on the formation and the characteristics of a nitrogen bubble injected from an orifice were studied experimentally and theoretically. This study was the first to divide the bubble growth process into four stages (waiting, expansion, deformation and detachment) according to the variation of the bubble shape in order to analyze the bubble behavior in the electric field. During the waiting stage, the waiting interval decreases significantly as the electric field strength rises. In the expansion stage, the minor axis reaches a maximum that decreases with increasing the electric field strength. Within the deformation stage, the major axis achieves its maximum and so does the aspect ratio. As the electric field strength rises, both the maximums of the major axis and the aspect ratio increase. At the detachment stage, as the electric field strength is intensified, the major axis lengthens, the minor axis shortens and the aspect ratio lengthens. From the waiting stage to the detachment stage, the effect of the electric field on the major axis of the bubble is marginal, while with increasing the electric field strength, the minor axis decreases distinctly and thus the aspect ratio increases. To employ the four-stage model, the bubble growth process was analyzed in detail under the electric field. The electric stress exerted on the bubble surface was calculated. The results show that the electric stress compresses the bubble equator and elongates the poles of the bubble, causing the bubble to elongate along the electric field direction.

Visualization of a Single Boiling Bubble in a DC Electric Field

2011 ◽  
Author(s):  
Feng Chen ◽  
Dong Liu ◽  
Yaozu Song ◽  
Yao Peng
Keyword(s):  
Heat Transfer ◽  
Life Cycle ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Wall Temperature ◽  
Boiling Heat Transfer ◽  
Bubble Dynamics ◽  
Nucleate Boiling ◽  
Dc Electric Field

The application of electric field has been demonstrated as an effective way to enhance pool boiling heat transfer. In past studies, adiabatic experiments were often conducted to simulate the dynamics of nucleate bubbles in the presence of an electric field, where gas bubbles were injected from an orifice, to avoid complexities involved in the nucleate boiling experiments. While adiabatic studies yield useful information of the bubble dynamics, further studies about bubble dynamics during nucleate boiling heat transfer are still necessary for a full understanding of the effects of applied electric field on the liquid-vapor phase change heat transfer. In this paper, the dynamics of a single boiling bubble in a direct current (DC) electric field was studied experimentally employing R113 as the working fluid. The life cycle of the boiling bubble was visualized using high-speed photography and was compared with that of an injected nitrogen bubble. Under the same electric field, a more appreciable elongation along the field direction was observed for the boiling bubble. A modified relationship between the bubble deformation and the electrical Weber number was proposed for the boiling bubble. As the electric field strength increases, it was found that, although the growth time of the boiling bubble increases, the waiting period decreases. However, it was also found that, the change of the whole life cycle with electric field strength increasing is relevant to the wall temperature. In this work, the wall temperature measured in the vicinity of the nucleation site upon the bubble departure decreases when the electric field is applied.

scholarly journals Numerical study for removing wax deposition by thermal washing for the waxy crude oil gathering pipeline

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042095852
Author(s):  
Hui Jiang ◽  
Xiaoyan Liu ◽  
Haiqian Zhao ◽  
Yang Liu ◽  
Chuan Ma ◽  
...  
Keyword(s):  
Crude Oil ◽  
Water Temperature ◽  
Flow Rate ◽  
Numerical Study ◽  
Liquid Fraction ◽  
Melting Process ◽  
Melting Rate ◽  
Melting Time ◽  
Outlet Temperature ◽  
Waxy Crude Oil

Exploring the wax removal process by numerical simulation is beneficial for guiding field operations. In this paper, enthalpy-porosity and volume of fluid (VOF) methods were adopted to simulate the melting process of wax in the crude oil gathering pipeline. The melting patterns and liquid fraction of the wax were used to validate the mathematical model. The results show that the wax melts quickly before the liquid fraction reaches 80%, while the remaining 20% melts very slowly. Since the water with higher density sinks to the lower part of the pipeline, the wax in the lower part of the pipeline melts first, while the wax in the upper part of the pipeline melts slowly. The water temperature and flow rate disproportionately affect the melting process. Increasing the water temperature and flow rate can accelerate the melting process, but the effects on shortening the melting time of wax gradually decrease. Increasing the flow rate, the heat transfer rate and the melting rate are increasing progressively, the change of flow rate also affects the outlet temperature of the pipeline.

Visualization of a Single Boiling Bubble in a DC Electric Field

2012 ◽  
Author(s):  
Feng Chen ◽  
Dong Liu ◽  
Yaozu Song
Keyword(s):  
Heat Transfer ◽  
Life Cycle ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Wall Temperature ◽  
Boiling Heat Transfer ◽  
Bubble Dynamics ◽  
Nucleate Boiling ◽  
Dc Electric Field

The application of electric field has been demonstrated as an effective way to enhance pool boiling heat transfer. In past studies, adiabatic experiments were often conducted to simulate the dynamics of nucleate bubbles in the presence of an electric field, where gas bubbles were injected from an orifice, to avoid complexities involved in the nucleate boiling experiments. While adiabatic studies yield useful information of the bubble dynamics, further studies about bubble dynamics during nucleate boiling heat transfer are still necessary for a full understanding of the effects of applied electric field on the liquid-vapor phase change heat transfer. In this paper, the dynamics of a single boiling bubble in a direct current (DC) electric field was studied experimentally employing R113 as the working fluid. The life cycle of the boiling bubble was visualized using high-speed photography and was compared with that of an injected nitrogen bubble. Under the same electric field, a more appreciable elongation along the field direction was observed for the boiling bubble. A modified relationship between the bubble deformation and the electrical Weber number was proposed for the boiling bubble. As the electric field strength increases, it was found that, although the growth time of the boiling bubble increases, the waiting period decreases. However, it was also found that, the change of the whole life cycle with electric field strength increasing is relevant to the wall temperature. In this work, the wall temperature measured in the vicinity of the nucleation site upon the bubble departure decreases when the electric field is applied.

Effect of Boron on the Melting Dynamics of Iron Base

2012 ◽  
Vol 189 ◽  
pp. 189-192 ◽  
Author(s):  
Ding Guo Zhao ◽  
Shu Huan Wang ◽  
Qiu Jing Li
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Transfer Rate ◽  
Pure Iron ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Melting Process ◽  
Melting Rate ◽  
Melting Time ◽  
Iron Base

Analyzed the melting process of iron base which contacted tightly with boron slag, established the boriding melting dynamical model of iron base and calculated the melting rate of pure iron. The melting rate of pure iron is not only decided by heat transfer rate, but also related to the mass transfer rate of boron. With the resolving of the model, we can know that the melting rate of pure iron is 3.41mm/min, and melting time is 15 min. When the speed of heating is high, the melting rate is mainly decided by diffusion.

scholarly journals A Study of Electric Field Effect on Melting of Octadecane

2016 ◽  
Vol 17 (2) ◽  
pp. 256-261
Author(s):  
S.G. Orlovskaya ◽  
F.F. Karimova ◽  
M.S. Shkoropado
Keyword(s):  
Electric Field ◽  
Melting Rate ◽  
Melting Time ◽  
Electric Field Effect ◽  
Shape Evolution ◽  
Solid Core ◽  
Droplet Shape ◽  
Melting Kinetics ◽  
Calculation Results ◽  
Kinetics Of

A new approach is developed to study melting kinetics of n-Octadecane. Modelling of heat transfer during the melting of solid particle is described. The calculation results are in good agreement with experimental data on melting duration. The effect of applied electric field on melting kinetics is studied. Almost twofold increase of melting time is found in an electric field of strength E = 82 kv/m. In addition a rotation of a solid core inside a melt is observed, which is a manifestation of Quinke effect. A droplet shape evolution during phase transition is described. It is shown that initially elongated particle is almost spherical near the melting point and elongates again with the temperature rise. This shape evolution is explained by non-monotonous change of surface tension and is connected with rotational phase. Thus a possibility is shown to control a melting rate of normal alkanes using electric field.

scholarly journals Measurement of Breakdown Electric Field Strength for Vegetation and Hydrocarbon Flames

2018 ◽  
Vol 10 (03) ◽  
pp. 53-66 ◽  
Author(s):  
Kago Ernest Maabong ◽  
Kgakgamatso Mphale ◽  
Douglas Letsholathebe ◽  
Samuel Chimidza
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Hydrocarbon Flames ◽  
Breakdown Electric Field
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