A5035963923- Welding Techniques and Residual Stresses
- Vacuum and Plasma Arcs
- Fluid Dynamics Simulations and Interactions
- Fluid Dynamics and Turbulent Flows
- nanoparticles nucleation surface interactions
- Lattice Boltzmann Simulation Studies
- Fluid Dynamics and Heat Transfer
- Particle Dynamics in Fluid Flows
- Dust and Plasma Wave Phenomena
- Plasma Diagnostics and Applications
- Metal and Thin Film Mechanics
- Non-Destructive Testing Techniques
- High-Temperature Coating Behaviors
- Laser-induced spectroscopy and plasma
- Laser-Ablation Synthesis of Nanoparticles
- Plasma and Flow Control in Aerodynamics
- Fluid Dynamics and Vibration Analysis
- Aerosol Filtration and Electrostatic Precipitation
- Aerodynamics and Fluid Dynamics Research
- Aerodynamics and Acoustics in Jet Flows
- Plasma Applications and Diagnostics
- Numerical methods in engineering
- Advanced Welding Techniques Analysis
- Spacecraft and Cryogenic Technologies
- Laser Material Processing Techniques
Tohoku University
2008-2024
Osaka University
2013-2022
Shanghai Shipbuilding Technology Research Institute
2014-2021
Osaka Research Institute of Industrial Science and Technology
2021
Murata (Japan)
2014
Engineering Systems (United States)
2009-2012
Ochanomizu University
2011
Tohoku University Hospital
2011
Tokyo Institute of Technology
2005-2006
Japan Society for the Promotion of Science London
2005
In this paper, we review the recent progress in nanofabrication by thermal plasmas, and attempt to define some of most important issues field. For synthesis nanoparticles, experimental studies past five years are briefly introduced; theoretical numerical modelling works 20 reviewed with detailed explanations. Also, use plasmas produce nanostructured films coatings is described. A wide range technologies have been developed, ranging from chemical vapour deposition processes new plasma...
This article presents a discussion of the ideas for modelling turbulent thermal plasma flows, reviewing challenges, efforts, and state-of-the-art simulations. Demonstrative simulations are also performed to present importance numerical methods as well physical models express features. A large eddy simulation has been applied flows treat time-dependent 3D motions multi-scale eddies. Sub-grid scale be used should able not only but laminar states because both co-exist in around plasmas which...
An experimental and computational study is conducted for the Si-based functional nanoparticle fabrication in an inductively coupled thermal plasma reactor. In study, improved multi-component co-condensation model with nodal discretization proposed to clarify growth mechanism consideration of coagulation thermophoresis as well simultaneous co-condensation. The by nucleation completes approximately 12.6 ms Mo–Si system 5.0 Ti–Si system. Mo nanoparticles grow advance, then Si vapour condenses...
A new model is developed for numerical analysis of the entire growth process binary alloy nanopowders in thermal plasma synthesis. The can express any nanopowder profile particle size-composition distribution (PSCD). Moreover, its solution algorithm arithmetic and straightforward so that easy to use. By virtue these features, effectively simulates collective simultaneous combined homogeneous nucleation, heterogeneous cocondensation, coagulation among nanoparticles. effect freezing point...
A mathematical model is developed to simulate the comprehensive systems of platinum nanoparticle synthesis using an argon inductively coupled thermal plasma flow with forced cooling portions. Numerical investigation conducted clarify and discuss effects several methods on formation mechanisms nanoparticles in distinctive thermofluid fields strong two dimensionality. The computational results show that by a radial gas injection, counterflow, engenders remarkable promotion nanoparticles.
Nano-particle synthesis by means of inductively coupled plasma torches is a material process large technological interest. Numerous parameters are involved in the optimization this process; hence development numerical models for prediction thermal and magneto-fluid dynamics fields, precursor powder trajectories history, as well nano-particle formation growth, necessary up-scaling these devices from laboratory batch production to an industrial continuous process. In work, two-dimensional (2D)...
A time-dependent 3D numerical simulation using a large eddy approach is conducted to meet the first challenge in revealing coherent vortex structure and dynamic behaviours of thermofluid field radio-frequency inductively coupled thermal plasma torch. The high-temperature region exhibits unsteady behaviour near coil. At same time, high- low-temperature flows form undulating interfaces. flow has complicated with recirculating zone due Lorentz forces. Because flow, injected cold gas tends avoid...
Aluminum alloys are increasingly being applied to automobile bodies reduce the weight of automobiles. In joining steel materials and aluminum using resistance spot welding(RSW), it is important control state intermetallic compounds due temperature at interface. other words, in RSW Fe/Al dissimilar materials, necessary clarify heating cooling phenomena interface during joining. Although convection behavior molten alloy thought influence distribution interface, there no studies that have...
Time-dependent three-dimensional numerical simulation based on a large-eddy approach is conducted to ascertain the complicated thermofluid dynamics of an argon radio-frequency (RF) inductively coupled plasma with direct-current (dc) jet assistance, considering non-uniform densities and properties in time space as well turbulence generation suppression. Using combination schemes suitable capture vortices, present successfully shows unsteady behaviour wave-like interfaces between...
An SPH simulation of a welding process is performed for TIG welding, taking account the melting and solidification anode metal, free surface movement liquid, four dominant flow-driving forces; gradient tension (Marangoni effect), gas drag on liquid surface, buoyancy, electromagnetic force (Lorentz force). The two metal blocks computed, including dynamic formation weld pool which joins gap between blocks. difference material's dependency to temperature causes significant in penetration. These...
This paper discusses theoretical models and numerical methods to simulate turbulent thermal plasma flow transporting a nanopowder. In addition model, sophisticated model is described mathematically for the nanopowder's collective growth by homogeneous nucleation, heterogeneous condensation, coagulation among nanoparticles, also transport convection, diffusion, thermophoresis, simultaneously. Demonstrative simulations show clearly that suitable method with high‐order accuracy should be used...
In this paper, quenching effects on silicon nanoparticle growth processes and size distributions at a typical range of cooling rates in thermal plasma tail are investigated computationally. We used nodal-type model that expresses distribution evolving temporally with simultaneous homogeneous nucleation, heterogeneous condensation, interparticle coagulation, melting point depression. The numerically obtained exhibit similar ranges tendencies to those experiment results without quenching....
A thermal plasma flow is regarded as a multifunctional fluid with high energy density, chemical reactivity, variable properties, and controllability by electromagnetic fields. Especially radio frequency inductively coupled (RF-ICP) has large volume, long reaction time, quenching rate. Besides, it inherently clean because produced without internal electrodes. An RF-ICP is, therefore, considered to be very useful for nanoparticle synthesis. However, synthesis using an includes complicated...
A computational investigation using a unique model and solution algorithm was conducted, changing only the saturation pressure of one material artificially during nanopowder formation in thermal plasma fabrication, to highlight effects difference between metal silicon. The can not express any profile particle size–composition distribution for metal–silicide even with widely ranging sizes from sub-nanometers few hundred nanometers, but it also simulate entire growth process involving binary...
A blue bilayer region presents in a helium tungsten inert gas (TIG) arc plasma on stainless steel. The indicates the presence of metal vapor. spectral intensity distributions vapors, including ions, steady state TIG steel were experimentally investigated by imaging spectroscopy. ionized vapors clearly observed plasma. vapor was affected electric field, which suggested that it transported through inside to cathode cataphoresis. Chromium widely distributed because more generated and easily...