Skip Nav Destination
Close Modal
Update search
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
NARROW
Format
Topics
Subjects
Article Type
Volume Subject Area
Date
Availability
1-3 of 3
S. Xue
Close
Follow your search
Access your saved searches in your account
Would you like to receive an alert when new items match your search?
Sort by
Proceedings Papers
ITSC 2007, Thermal Spray 2007: Proceedings from the International Thermal Spray Conference, 167-172, May 14–16, 2007,
Abstract
View Paper
PDF
A consistent thermal and chemical non-equilibrium model for inductive supersonic plasma flow, developed recently, is applied to the modelling of pure argon supersonic plasma flow, which impinges on a substrate below the Mach 1 nozzle. The model considers the ionization of argon atom and the corresponding recombination but the second order ionization is ignored and plasma charge neutrality is assumed. The transport and mass diffusion coefficients are computed using the collision cross-section data, published by Devoto and Murphy and the computations of transport properties are fully coupled with the calculation of the plasma flow fields. The model treats the subsonic discharge region above the supersonic nozzle and the supersonic region below the nozzle together. Two different turbulent models are incorporated into the model to describe the supersonic plasma flow. The modeled radial and axial profiles of electron and heavy species temperatures and electron number densities near the substrate are then compared to those measured by the method of optical emission spectroscopy and finally the most realistic model is identified.
Proceedings Papers
ITSC 2005, Thermal Spray 2005: Proceedings from the International Thermal Spray Conference, 305-310, May 2–4, 2005,
Abstract
View Paper
PDF
A thermal and chemical non-equilibrium model is developed for the modelling of multi-component supersonic induction Ar-H 2 plasma flows. The species included in the modelling are electrons(e), hydrogen ion(H+), hydrogen atoms(H), hydrogen molecules(H 2 ), Argon ions(Ar+) and Argon atoms(Ar). The negative hydrogen ions(H-), molecular hydrogen ions(H 2 +) and second order ionisation are neglected. The chemical reactions considered in the modelling are the H 2 dissociations and the corresponding recombination, induced by Ar atom and H 2 , and the ionisations of the hydrogen and Argon and the corresponding recombination. All the heavy species are assumed to have the same temperature (Ti). The electron temperature (Te) is allowed to deviate from that of heavy species. The energies for these chemical reactions have been treated as the source terms for energy conservation equations. As a result, the contributions of these chemical reactions to the total enthalpy are removed. Therefore, the heavy species temperature can be obtained by solving the thermal kinetic energy equation, rather than the total enthalpy equation. Yos’s mixing law is used to calculate the contribution of vibrational and rotational energies of hydrogen molecules to the thermal conductivity of heavy species. The transport properties are calculated using the formulas derived by Hirschfelder, Curtiss and Bird. The data of collision integrals or collision cross-sections between species in the mixture are taken from Murphy, Devoto and Mason’s publications. The binary mass diffusion coefficients between the species in the mixture are also calculated from these collision integral data. The mass diffusion of species in the mixture are modelled under the dilute approximation at present since the mole fraction of the principal species, Argon, in the whole computational region is more than 90%. For charged species, Ambipolar diffusion coefficients are used. Mass balance equations are solved to obtain the mass fractions or mole fractions or the number densities of all the species except for electrons. The electron number density is determined by the condition of electrical neutrality. The developed model is applied to the modelling of inductive plasma flow, generated by the Tekna PL-35 torch model, under different pressures and then to the supersonic plasma flow. The model has been validated by comparing the transport properties under the LTE conditions from this model with the corresponding published values.
Proceedings Papers
ITSC 2003, Thermal Spray 2003: Proceedings from the International Thermal Spray Conference, 993-999, May 5–8, 2003,
Abstract
View Paper
PDF
Various turbulent models (Spalart-Allmaras, Standard k-ε, RNG k-ε, Realizable k-ε and Reynolds Stress Models) along with Standard, and two-zonal wall functions are used to simulate inductively coupled plasma flows. The computational results can be classified into two categories: All the turbulent models that include low Reynolds number effects, such as, Low Reynolds number k-ε model, Spalart-Allmaras one-equation model, Standard k-ε model with two-zonal wall function, RNG model with turbulent viscosity determined by a differential equation, RSM etc., give similar modelling results. These models predict almost the same temperature contours which are similar to the one predicted by laminar model. The viscosity ratios in plasma region predicted by these models are very close to zero except for in the wall-neighbouring cells, which means the plasma flow is almost laminar. The other category contains those models that do not include the low Reynolds number effects, such as Standard, RNG and so-called Realizable k-ε models with standard wall function. They predict the plasma flow to be turbulence-dominated. In comparison with the results of experimentally measured heat fluxes to a substrate, the heat fluxes predicted by these models that include low Reynolds number effect are very close to experimental measurements while these models that do not include low Reynolds number effects deviate greatly from experimental measurements. It is found that the Reynolds stress model(RSM) appears to be the best predictive model.