Simulation and Modeling of Turbulent Plasma Jet Based on Axisymetric LBGK Model

2011 ◽  
Vol 312-315 ◽  
pp. 1167-1171 ◽  
Author(s):  
Ridha Djebali ◽  
Mohammed El Ganaoui ◽  
Bernard Pateyron ◽  
Habib Sammouda
Keyword(s):  
Plasma Spraying ◽  
High Performance ◽  
Plasma Jet ◽  
Experimental Tests ◽  
Solution Procedure ◽  
Industrial Applications ◽  
Plasma Jets ◽  
Diffusion Parameters ◽  
Complex Phenomena ◽  
Economic Constraints

The coating of surfaces by plasma spraying is an important manufacturing process with many industrial applications. In the last several decades, numerical modeling of plasma spraying processes has met with considerable attention [1,2,3]. That is in order to well understand the complex phenomena the plasma spray involves, for economic constraints and to well predict the plasma-inflight-particles exchanges since this affects directly the coating formability and microstructure. This study deals with the investigation of plasma jets using an axisymmetric LB thermal model. Plasma jets have been very successful in many applications (such as spraying, cutting, welding,…). The excellent choice of high performance plasma gases and spraying materials has been the subject of several experimental and numerical efforts. An excellent choice will be the response of efficient numerical studies and the results of experimental tests. Plasma jets are high temperature flows (>8000K). Therefore, all diffusion parameters involved in conservation equations are temperature dependent. In the following, we present a plasma jet investigation in an axisymmetric LBM (Jian’s model [4]). In the context of our knowledge, it is the first attempt to tackle this field by using the LBM. Further reading on solution procedure, the model implementation and assumptions may be found in [5,6].

scholarly journals High-Speed Video Analysis of the Process Stability in Plasma Spraying

2021 ◽  
Author(s):  
K. Bobzin ◽  
M. Öte ◽  
M. A. Knoch ◽  
I. Alkhasli ◽  
H. Heinemann
Keyword(s):  
Plasma Spraying ◽  
High Speed ◽  
Plasma Jet ◽  
Plasma Jets ◽  
Time Dependent ◽  
Acquisition Time ◽  
Fast Fourier Transformation ◽  
Frequency Spectra ◽  
Dependent Signal ◽  
The Stability

AbstractIn plasma spraying, instabilities and fluctuations of the plasma jet have a significant influence on the particle in-flight temperatures and velocities, thus affecting the coating properties. This work introduces a new method to analyze the stability of plasma jets using high-speed videography. An approach is presented, which digitally examines the images to determine the size of the plasma jet core. By correlating this jet size with the acquisition time, a time-dependent signal of the plasma jet size is generated. In order to evaluate the stability of the plasma jet, this signal is analyzed by calculating its coefficient of variation cv. The method is validated by measuring the known difference in stability between a single-cathode and a cascaded multi-cathode plasma generator. For this purpose, a design of experiment, covering a variety of parameters, is conducted. To identify the cause of the plasma jet fluctuations, the frequency spectra are obtained and subsequently interpreted by means of the fast Fourier transformation. To quantify the significance of the fluctuations on the particle in-flight properties, a new single numerical parameter is introduced. This parameter is based on the fraction of the time-dependent signal of the plasma jet in the relevant frequency range.

scholarly journals Study of Modified Area of Polymer Samples Exposed to a He Atmospheric Pressure Plasma Jet Using Different Treatment Conditions

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1028 ◽  
Author(s):  
Thalita M. C. Nishime ◽  
Robert Wagner ◽  
Konstantin G. Kostov
Keyword(s):  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Industrial Applications ◽  
Plasma Jets ◽  
Limited Area ◽  
Plastic Tube ◽  
Pressure Plasma ◽  
Treatment Conditions ◽  
Jet Modification

In the last decade atmospheric pressure plasma jets (APPJs) have been routinely employed for surface processing of polymers due to their capability of generating very reactive chemistry at near-ambient temperature conditions. Usually, the plasma jet modification effect spans over a limited area (typically a few cm²), therefore, for industrial applications, where treatment of large and irregular surfaces is needed, jet and/or sample manipulations are required. More specifically, for treating hollow objects, like pipes and containers, the plasma jet must be introduced inside of them. In this case, a normal jet incidence to treated surface is difficult if not impossible to maintain. In this paper, a plasma jet produced at the end of a long flexible plastic tube was used to treat polyethylene terephthalate (PET) samples with different incidence angles and using different process parameters. Decreasing the angle formed between the plasma plume and the substrate leads to increase in the modified area as detected by surface wettability analysis. The same trend was confirmed by the distribution of reactive oxygen species (ROS), expanding on starch-iodine-agar plates, where a greater area was covered when the APPJ was tilted. Additionally, UV-VUV irradiation profiles obtained from the plasma jet spreading on the surface confirms such behavior.

scholarly journals Benefits of Hydrogen in a Segmented-Anode Plasma Torch in Suspension Plasma Spraying

2021 ◽  
Author(s):  
Alice Dolmaire ◽  
Enni Hartikainen ◽  
Simon Goutier ◽  
Emilie Béchade ◽  
Michel Vardelle ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Gas Turbines ◽  
Gas Flow ◽  
Plasma Jet ◽  
Plasma Jets ◽  
Suspension Plasma Spraying ◽  
Mechanical And Thermal Properties ◽  
Mean Velocity ◽  
Zone Length ◽  
Plasma Torches

AbstractSuspension plasma spraying (SPS) enables the production of various coating microstructures with unique mechanical and thermal properties. Aeronautical manufacturers have been working for fifty years to improve the thermal barrier coating (TBC) performances in gas turbines. Commercial plasma torches with a segmented anode that are characterized by stable plasma jets should enable a better control of the TBC microstructure. The addition of diatomic gases such as hydrogen in the plasma-forming gas affects the plasma jet formation and causes some instabilities. However, it enhances the thermal conductivity of the gas flow, the plasma mass enthalpy and the heat transfer to particles. This study aims to characterise and describe the coating microstructure changes of yttria-stabilised zirconia when gradually adding hydrogen with argon into the plasma gas mixture. The effect of hydrogen is weighted out due to the gas mass enthalpy, mean velocity at the nozzle exit and “hot zone” length of the plasma jet. The coating microstructures, which depend on these plasma jet parameters, will be mapped from feathery and porous to dense and cracked deposits depending on the spraying conditions.

Melting Phenomena of Several Nickel Base Alloys in a Plasma Jet Operating at Low Pressure

1987 ◽  
Vol 98 ◽  
Author(s):  
Ronald W. Smith ◽  
Diran Apelian
Keyword(s):  
Nickel Alloy ◽  
Plasma Spraying ◽  
High Performance ◽  
Plasma Processing ◽  
Plasma Jet ◽  
Melting Behavior ◽  
Processing Parameters ◽  
High Density ◽  
Powder Particles ◽  
Nickel Base

ABSTRACTThe modeling of powders melting in a plasma jet has received increasing attention as the plasma spraying is being developed to produce high density, high performance materials. These models are being used to predict process capability for melting powders and to develop plasma processing parameters for complete particle melting. Most models assume splherical powder particles which heat and melt uniformly during their travel in the plasma jet. The results of this research indicate this assumption may be invalid. Several experiments conducted to evaluate the melting behavior of nickel and nickel alloy powders (Ni,Ni2OCu, Ni2OCr, Ni5O Cr, Rene'80) are presented.

Combined Experimental and Numerical Analysis of the Influence of Air-to-Fuel Ratio on Cyclic Variation of High Performance Engines

2008 ◽  
Author(s):  
Claudio Forte ◽  
Gian Marco Bianchi ◽  
Enrico Corti ◽  
Stefano Fantoni
Keyword(s):  
High Performance ◽  
Combustion Process ◽  
Experimental Tests ◽  
Cylinder Pressure ◽  
Pressure Data ◽  
Si Engine ◽  
Complex Phenomena ◽  
Experimental Pressure ◽  
Mixture Homogeneity ◽  
Insight Into

The Cycle by Cycle Variation (CCV) of a SI engine is analyzed by combining experimental tests and numerical investigations. The quantification of CCV is based on the evaluation of the Coefficient of Variance (COV) of IMEP. The analysis of the experimental pressure data shows an increase in CCV towards leaner mixture conditions. The evaluation of the Heat Release Rate from the in-cylinder pressure traces reveals the strong influence of the early stages of combustion on the variability of the flame evolution. In order to evaluate the influence on CCV of local air equivalence ratio cycle-to-cycle variability and mixture homogeneity in the chamber, a numerical CFD methodology for the simulation of the combustion process has been proposed. The results reproduce with reasonable accuracy the increase in CCV with leaner combustions and put the basis for a deeper insight into the complex phenomena involved in the combustion process by the use of parametric analysis.

scholarly journals Tiny Cold Atmospheric Plasma Jet for Biomedical Applications

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 249
Author(s):  
Zhitong Chen ◽  
Richard Obenchain ◽  
Richard E. Wirz
Keyword(s):  
Biomedical Applications ◽  
Plasma Jet ◽  
Discharge Voltage ◽  
Plasma Jets ◽  
Atmospheric Plasma ◽  
Physical Parameters ◽  
Cold Atmospheric Plasma ◽  
Water Metal ◽  
Plasma Probe ◽  
Jet Nozzle

Conventional plasma jets for biomedical applications tend to have several drawbacks, such as high voltages, high gas delivery, large plasma probe volume, and the formation of discharge within the organ. Therefore, it is challenging to employ these jets inside a living organism’s body. Thus, we developed a single-electrode tiny plasma jet and evaluated its use for clinical biomedical applications. We investigated the effect of voltage input and flow rate on the jet length and studied the physical parameters of the plasma jet, including discharge voltage, average gas and subject temperature, and optical emissions via spectroscopy (OES). The interactions between the tiny plasma jet and five subjects (de-ionized (DI) water, metal, cardboard, pork belly, and pork muscle) were studied at distances of 10 mm and 15 mm from the jet nozzle. The results showed that the tiny plasma jet caused no damage or burning of tissues, and the ROS/RNS (reactive oxygen/nitrogen species) intensity increased when the distance was lowered from 15 mm to 10 mm. These initial observations establish the tiny plasma jet device as a potentially useful tool in clinical biomedical applications.

Dioxazine pigments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Christie ◽  
Adrian Abel
Keyword(s):  
High Performance ◽  
Industrial Applications ◽  
Textile Dye ◽  
Linear Arrangement ◽  
Natural Colorant ◽  
X Ray ◽  
Organic Pigments ◽  
Tyrian Purple ◽  
Violet Color ◽  
The Individual

Abstract This chapter provides an overview of the structural and synthetic chemistry, and the industrial applications, of dioxazine pigments, a small group of high performance organic pigments. The color violet (or purple) has frequently assumed a prominent position in history, on account of its rarity and cost. The natural colorant Tyrian purple and the first synthetic textile dye, Mauveine, are prime examples of this unique historical feature. CI Pigment Violet 23, also referred to as Dioxazine Violet or Carbazole Violet, is one of the most universally used organic pigments, by far the most important industrial pigment in the violet shade area. Dioxazine Violet is also unique as the dominant industrial violet pigment providing a brilliant, intense violet color and an excellent all-round set of fastness properties. The pigment has a polycyclic molecular structure, originally described wrongly as a linear arrangement, and later shown to adopt an S-shaped arrangement on the basis of X-ray structural analysis. Two other dioxazine pigments are of rather lesser importance. The synthesis and manufacturing route to CI Pigment Violet 23 is described in the review. Finally, a survey of the principal current applications of the individual dioxazine pigments is presented.

Review on modification strategies of polyethylene/polypropylene immiscible thermoplastic polymer blends for enhancing their mechanical behavior

2018 ◽  
Vol 51 (4) ◽  
pp. 291-336 ◽  
Author(s):  
Antimo Graziano ◽  
Shaffiq Jaffer ◽  
Mohini Sain
Keyword(s):  
High Performance ◽  
Cost Effective ◽  
Good Method ◽  
Waste Recycling ◽  
Industrial Applications ◽  
Polymer Waste ◽  
Reactive Compatibilization ◽  
Brittle To Ductile Transition ◽  
Commercial Applications ◽  
Effective Product

Blends of polyethylene (PE) and polypropylene (PP) have always been the subject of intense reasearch for encouraging polymer waste recycling while producing new materials for specific applications in a sustainable way. However, being thermodynamically immiscible, these polyolefins form a binary system usually exhibiting lower performances compared with those of the homopolymers. Many studies have been carried out to better understand the PE/PP blend compatibilization for developing a high-performance and cost-effective product. Both nonreactive and reactive compatibilization promote the brittle to ductile transition for a PE/PP blend. However, the final product usually does not meet the requirements for high demanding commercial applications. Therefore, further PE/PP modification with a reinforcing filler, being either synthetic or natural, proved to be a good method for manufacturing high-performance reinforcend polymer blend composites, with superior and tailored properties. This review summarizes the recent progress in compatibilization techniques applied for enhancing the interfacial adhesion between PE and PP. Moreover, future perspectives on better understanding the influence of themodynamics on PE/PP synergy are discussed to introduce more effective compatibilization strategies, which will allow this blend to be used for innovative industrial applications.

Development and Achievements of SSM Processes for High Performance Components

2016 ◽  
Vol 256 ◽  
pp. 319-327 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Ivano Gattelli
Keyword(s):  
Industrial Development ◽  
High Performance ◽  
Rear Axle ◽  
Research Work ◽  
Industrial Applications ◽  
Alternative Methods ◽  
Front Suspension ◽  
Large Numbers ◽  
Automotive Parts ◽  
High Level

During the last decades under the enthusiastic and competent guidance of Mr Chiarmetta SSM processes attained in Italy at Stampal Spa (Torino) an unquestionable high level of industrial development with the production of large numbers of high performance automotive parts, like variety of suspension support, engine suspension mounts, steering knuckle, front suspension wheel, arm and rear axle. Among the most highlighted findings SSM processes demonstrated their capability to reduce the existing gap between casting and forging, moreover during such a processes there are the opportunity to better control the defect level.Purpose of this paper is to highlight the research work and the SSM industrial production attained and developed by Mr G.L. Chiarmetta, as well as to give an overview concerning some alternative methods for the production of enhanced performance light alloys components for critical industrial applications and to present an analysis of a new rheocasting process suitable for the manufacturing of high performance industrial components.

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