Modeling of Ceramic Particle Heating and Melting in a Microwave Plasma

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Kaushik Saha ◽  
Swetaprovo Chaudhuri ◽  
Baki M. Cetegen
Keyword(s):  
Flow Field ◽  
Plasma Flow ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Ceramic Particle ◽  
Spherical Particles ◽  
Air Plasma ◽  
Coupling Region ◽  
Ceramic Particles ◽  
Different Diameters

A comprehensive model based on finite volume method was developed to analyze the heat-up and the melting of ceramic particles injected into a microwave excited laminar air plasma flow field. Plasma flow field was simulated as a hot gas flow generated by volumetric heat addition in the microwave coupling region, resulting in a temperature of 6000 K. Alumina and zirconia particles of different diameters were injected into the axisymmetric laminar plasma flow at different injection velocities and locations. Additionally, noncontinuum effects, variation of transport properties of plasma surrounding the spherical particles and absorption of microwave radiation in the ceramic particles were considered in the model. Model predictions suggest that zirconia and alumina particles with diameters less than 50 μm can be effectively melted in a microwave plasma and can produce more uniform melt states. Microwave plasma environment with the ability to inject particles into the plasma core provide the opportunity to create more uniform melt states as compared with dc arc plasmas that are influenced by characteristic arc root fluctuations and turbulent dispersions.

Effect of Temperature Dependent Properties and Particle Shape on Heat Transfer in Plasma Flow

2003 ◽  
Author(s):  
Yuemin Wen ◽  
Milind A. Jog
Keyword(s):  
Flow Field ◽  
Plasma Flow ◽  
Particle Shape ◽  
Flow Direction ◽  
Particle Surface ◽  
Spherical Particles ◽  
Effect Of Temperature ◽  
Far Field ◽  
Constant Property ◽  
Axis Ratio

In this paper, plasma flow over non-spherical particles has been investigated numerically. The conservation equations for mass, momentum, and energy are solved simultaneously using finite volume method. To body-fit the non-spherical particle surface, an adaptive orthogonal grid is generated. The flow field and the temperature distribution are calculated for oblate and prolate particle shapes. A number of particle surface temperatures and far field temperatures are considered and thermophysical property variation is fully accounted for in our model. The shapes are represented in terms of variations in the axis ratio which is defined as the ratio of axis along the flow direction to the axis perpendicular to the flow direction. For oblate shape, axis ratios from 0.4 (disk-like) to 1 (sphere) are used whereas for proate shape, axis ratios of 1 (sphere) to 1.6 (cylinder-like) are used. The computational model is first validated by comparison with results and correlations available in literature for constant property flow. Effects of flow Reynolds number, particle shape, surface and far field temperatures, and variable properties, on the flow field, temperature variations, drag coefficient, and Nusselt number are outlined.

Spectroscopic Measurement of Air Plasma Flow Generated by 10kW Class ICP Heater

2019 ◽  
Vol 67 (2) ◽  
pp. 42-48
Author(s):  
Mayuko Tanaka ◽  
Kazuhiko Yamada ◽  
Yusuke Takahashi ◽  
Minghao Yu ◽  
Asei Tezuka
Keyword(s):  
Plasma Flow ◽  
Spectroscopic Measurement ◽  
Air Plasma

scholarly journals A self-boosting microwave plasma strategy tuned by air pressure for the highly efficient and controllable surface modification of carbon

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 9955-9963
Author(s):  
Yanjing Liu ◽  
Jiawei He ◽  
Bing Zhang ◽  
Huacheng Zhu ◽  
Yang Yang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Carbon Fiber ◽  
High Efficiency ◽  
Microwave Plasma ◽  
Air Pressure ◽  
Air Plasma ◽  
Highly Efficient ◽  
Carbon Fiber Cloth

Microwave enabled air plasma was boosted by a carbon fiber cloth (CFC) and used for the high-efficiency surface modification of the CFC, yielding CFCs with tunable contents of oxygen and each O-containing group.

scholarly journals Influence of gas flow on argon microwave plasma jet at atmospheric pressure

2011 ◽  
Vol 206 (6) ◽  
pp. 1449-1453 ◽  
Author(s):  
Shouichiro Iio ◽  
Kosuke Yanagisawa ◽  
Chizuru Uchiyama ◽  
Katsuya Teshima ◽  
Naomichi Ezumi ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Plasma Jet

Numerical Analysis of Flow Fields and Temperature Fields in a Regenerative Heating Furnace for Steel Pipes

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Yi Han ◽  
Feng Liu ◽  
Xin Ran
Keyword(s):  
Temperature Field ◽  
Flow Field ◽  
Flow Velocity ◽  
Gas Flow ◽  
Flow Fields ◽  
Heating Furnace ◽  
Temperature Fields ◽  
Turbulent Layer ◽  
Steel Pipes ◽  
Pipe Blanks

In the production process of large-diameter seamless steel pipes, the blank heating quality before roll piercing has an important effect on whether subsequently conforming piping is produced. Obtaining accurate pipe blank heating temperature fields is the basis for establishing and optimizing a seamless pipe heating schedule. In this paper, the thermal process in a regenerative heating furnace was studied using fluent software, and the distribution laws of the flow field in the furnace and of the temperature field around the pipe blanks were obtained and verified experimentally. The heating furnace for pipe blanks was analyzed from multiple perspectives, including overall flow field, flow fields at different cross sections, and overall temperature field. It was found that the changeover process of the regenerative heating furnace caused the temperature in the upper part of the furnace to fluctuate. Under the pipe blanks, the gas flow was relatively thin, and the flow velocity was relatively low, facilitating the formation of a viscous turbulent layer and thereby inhibiting heat exchange around the pipe blanks. The mutual interference between the gas flow from burners and the return gas from the furnace tail flue led to different flow velocity directions at different positions, and such interference was relatively evident in the middle part of the furnace. A temperature “layering” phenomenon occurred between the upper and lower parts of the pipe blanks. The study in this paper has some significant usefulness for in-depth exploration of the characteristics of regenerative heating furnaces for steel pipes.

NbC and VC Nanoparticles Reinforced Fe-Si-Mn Matrix Composite In Situ Synthesized by Plasma Jet

2011 ◽  
Vol 415-417 ◽  
pp. 71-75
Author(s):  
Chun Xiang Cui ◽  
Yan Chun Li ◽  
Tie Bao Wang ◽  
Shuang Jin Liu ◽  
Suek Bong Kang
Keyword(s):  
Matrix Composite ◽  
Hybrid Composite ◽  
Gas Flow ◽  
Plasma Jet ◽  
Homogeneous Distribution ◽  
Active Nitrogen ◽  
Ceramic Particles ◽  
Nanometer Range ◽  
Short Time

In situ NbC and VC nanoparticles reinforced Fe-Si-Mn-Nb-V matrix composite was carried out using a plasma jet with a plasma gas flow of (Ar + CH4) for very short time. The process involve improving the efficiency of the reaction in terms of consumption of the available active nitrogen atoms as well as the production of very fine and homogeneous distribution of all reinforcing phases of ceramic particles, preferable in the nanometer range. The nanoreinforcements synthesized by in situ reaction in this hybrid composite are NbC and VC ceramic particles.

Modeling of Flow Fields of Different Delivery Chamfers in Spray Forming Process

2014 ◽  
Vol 789 ◽  
pp. 554-559
Author(s):  
Yang Liu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Wen Yong Xu
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Metal Flow ◽  
Spray Forming ◽  
Operating Pressure ◽  
Delivery Tube ◽  
Forming Process ◽  
Atomization Process ◽  
Sharp Point

The computational fluid dynamic (CFD) software was used to calculate the velocity field in atomization chamber of spray forming equipment. The relationship between melt flow rates, gas aspiration of the atomizer and operating pressure are complex, and the above mentioned parameters are closely related to the atomization process. The influences of different delivery chamfers on gas flow field, which is determined by atomizer structure, were analyzed. Using K-epsilon model with a symmetrical domain, the gas dynamic of different delivery chamfer conditions were investigated. The results indicate that the sharp point of delivery tube causes detachment of flow field, and 56°, 45° and 34° chamfer conditions have same diffusion angle. Gas was aspirated from delivery tube when chamfer was 0°, which is beneficial to liquid metal flow in atomization process.

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