Skip Nav Destination
Close Modal
Search Results for
computational fluid dynamics
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
1-20 of 371
Search Results for computational fluid dynamics
Follow your search
Access your saved searches in your account
Would you like to receive an alert when new items match your search?
1
Sort by
Proceedings Papers
Spray Pattern of Aluminum Coatings with the Rectangular Cross-Section Nozzle Calculated by the Computational Fluid Dynamics (CFD) in High-Pressure Cold Spray
Available to Purchase
ITSC 2021, Thermal Spray 2021: Proceedings from the International Thermal Spray Conference, 214-220, May 24–28, 2021,
... and particle by the computational fluid dynamics (CFD) in high pressure cold spraying. We have studied copper particles so far. In this study, we will examine aluminum particles. First, we investigate the influence of the size and shape of the rectangular section nozzle on the velocity, temperature...
Abstract
View Papertitled, Spray Pattern of Aluminum Coatings with the Rectangular Cross-Section Nozzle Calculated by the <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> (CFD) in High-Pressure Cold Spray
View
PDF
for content titled, Spray Pattern of Aluminum Coatings with the Rectangular Cross-Section Nozzle Calculated by the <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> (CFD) in High-Pressure Cold Spray
In the cold spray process, cross-sectional shape of the nozzle has a significant effect on spray pattern of coatings. The circular exit nozzle is parabolic in shape. So, spray pattern with the rectangular nozzle is wider than that with the circular spray nozzle. The goal of this investigation is to establish a design for the cold spray gun nozzle to gain more uniform spray profile of coatings. We have investigated the influence of expansion ratio, nozzle total length and the ratio of nozzle length of divergent section and parallel section of rectangular nozzle on behaviors of gas and particle by the computational fluid dynamics (CFD) in high pressure cold spraying. We have studied copper particles so far. In this study, we will examine aluminum particles. First, we investigate the influence of the size and shape of the rectangular section nozzle on the velocity, temperature, and particle distribution of aluminum particles by CFD. After that, the rectangular section nozzles were fabricated and coating formation experiments were conducted, spray patterns and coating cross-sectional structures were observed, and coating adhesion was also evaluated. The nozzle material was polybenzimidazole resin, which is difficult for aluminum particles to attach to nozzle walls.
Proceedings Papers
Computational Fluid Dynamics Analysis of Gas and Particle Flow in Flame Spraying
Available to Purchase
ITSC2000, Thermal Spray 2000: Proceedings from the International Thermal Spray Conference, 237-244, May 8–11, 2000,
... Abstract The industrial flame spraying process has been analyzed by three-dimensional Computational Fluid Dynamics (CFD) simulation. The actual process is employed at the Volvo Aero Corporation for coating of fan and compressor housings. It involves the Metco 6P gun where the fuel, a mixture...
Abstract
View Papertitled, <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Analysis of Gas and Particle Flow in Flame Spraying
View
PDF
for content titled, <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Analysis of Gas and Particle Flow in Flame Spraying
The industrial flame spraying process has been analyzed by three-dimensional Computational Fluid Dynamics (CFD) simulation. The actual process is employed at the Volvo Aero Corporation for coating of fan and compressor housings. It involves the Metco 6P gun where the fuel, a mixture of acetylene and oxygen, flows through a ring of 16 orifices, while the coating material, a powder of nickel-covered bentonite, is sprayed through the flame with a stream of argon as a carrier gas by a central orifice. The gas flow was simulated as a multi-component chemically reacting incompressible flow. The standard, two equations, k-e turbulence model was employed for the turbulent flow field. The reaction rates appeared as source terms in the species transport equations. They were computed from the contributions of the Arrhenius rate expressions and the Magnussen and Hjertager eddy dissipation model. The particles were modeled using a Lagrangian particle spray model. In spite of the complexity of the system, the complex geometry and the numerous chemical reactions, the simulations produced fairly good agreement with experimental measurements. The powder size distribution was found to play a critical role in the amount of unmelted fraction of particles. The modeling approach seems to give a realistic description of the physical phenomena involved in flame spraying, albeit some model refinement is needed.
Proceedings Papers
ITSC 2019, Thermal Spray 2019: Proceedings from the International Thermal Spray Conference, 279-284, May 26–29, 2019,
... deposition efficiency at a reasonable gas pressure. cold spraying computational fluid dynamics copper particles deposition efficiency gas pressure nozzle geometry ITSC 2019 Proceedings of the International Thermal Spray Conference May 26 29, 2019, Yokohama, Japan F. Azarmi, Y. Lau, J. Veilleux...
Abstract
View Papertitled, Influence of Nozzle Expansion Ratio of Circular and Rectangular Cross-Section Nozzle on Velocity and Temperature of Copper Particle with HP Cold Spraying by <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> and Experimental Analysis
View
PDF
for content titled, Influence of Nozzle Expansion Ratio of Circular and Rectangular Cross-Section Nozzle on Velocity and Temperature of Copper Particle with HP Cold Spraying by <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> and Experimental Analysis
This study compares the performance of circular and rectangular cold spray nozzles based on numerical simulations and experimental results. It shows how nozzle geometry and gas pressure affect the velocity and temperature of copper particles at various points in their travel. The goal of the investigation is to establish a nozzle design that achieves a uniform spray pattern with suitable particle impact velocity for the materials and temperatures involved. It was found that a rectangular nozzle with an expansion ratio in the range of 11-12 can provide a more uniform particle velocity with high deposition efficiency at a reasonable gas pressure.
Proceedings Papers
Computational Fluid Dynamics Analysis of a Wire-Feed, High-Velocity Oxygen-Fuel (HVOF) Thermal Spray Torch
Available to Purchase
ITSC1996, Thermal Spray 1996: Proceedings from the National Thermal Spray Conference, 531-540, October 7–11, 1996,
... Abstract The fluid and particle dynamics of a High-Velocity Oxygen-Fuel Thermal Spray torch are analyzed using computational and experimental techniques. Three-dimensional Computational Fluid Dynamics (CFD) results are presented for a curved aircap used for coating interior surfaces...
Abstract
View Papertitled, <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Analysis of a Wire-Feed, High-Velocity Oxygen-Fuel (HVOF) Thermal Spray Torch
View
PDF
for content titled, <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Analysis of a Wire-Feed, High-Velocity Oxygen-Fuel (HVOF) Thermal Spray Torch
The fluid and particle dynamics of a High-Velocity Oxygen-Fuel Thermal Spray torch are analyzed using computational and experimental techniques. Three-dimensional Computational Fluid Dynamics (CFD) results are presented for a curved aircap used for coating interior surfaces such as engine cylinder bores. The device analyzed is similar to the Metco Diamond Jet Rotating Wire (DJRW) torch. The feed gases are injected through an axisymmetric nozzle into the curved aircap. Premixed propylene and oxygen are introduced from an annulus in the nozzle, while cooling air is injected between the nozzle and the interior wall of the aircap. The combustion process is modeled using a single-step finite- rate chemistry model with a total of 9 gas species which includes dissociation of combustion products. A continually-fed steel wire passes through the center of the nozzle and melting occurs at a conical tip near the exit of the aircap. Wire melting is simulated computationally by injecting liquid steel particles into the flow field near the tip of the wire. Experimental particle velocity measurements during wire feed were also taken using a Laser Two-Focus (L2F) velocimeter system. Flow fields inside and outside the aircap are presented and particle velocity predictions are compared with experimental measurements outside of the aircap.
Proceedings Papers
Flame Flow Analysis for HVOF/HVAF System by Two-Dimension Computational Fluid Dynamics Method
Available to Purchase
ITSC 2007, Thermal Spray 2007: Proceedings from the International Thermal Spray Conference, 163-166, May 14–16, 2007,
... an opposite behavior. At the gun exit, the combustion gas reaches supersonic velocities both for the HVOF and HVAF condition. computational fluid dynamics flame flow analysis high-velocity airfuel spray coating high-velocity oxyfuel spray coating Thermal Spray 2007: Proceedings from...
Abstract
View Papertitled, Flame Flow Analysis for HVOF/HVAF System by Two-Dimension <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Method
View
PDF
for content titled, Flame Flow Analysis for HVOF/HVAF System by Two-Dimension <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Method
Based on the principle of the liquid-fueled rocket engine, a combustion model is proposed for the HVOF/HVAF system. The combustion gas components and temperature for different mixture fractions were analyzed. At lower oxygen content condition (under-stoichiometry), the combustion temperature is lower and the solid carbon content is higher. The whole fluent flow mode was proposed for the supersonic spray, which consists of the gas combustion, the accelerating process, the cooling process and the decelerating process in the atmosphere. The velocity and temperature distributions were calculated according to this model; the results fitted well with experiments. The combustion gas parameter distributions are almost identical in the barrel, but differ significantly in the atmosphere. For HVOF system, the under-expanded gas will expand in the atmosphere, while HVAF system exhibits an opposite behavior. At the gun exit, the combustion gas reaches supersonic velocities both for the HVOF and HVAF condition.
Proceedings Papers
Spray Pattern and Microstructure of Copper Coatings with the Optimized Rectangular Cross-Section Nozzle by the Computational Fluid Dynamics (CFD) in High-Pressure Cold Spraying
Available to Purchase
ITSC 2017, Thermal Spray 2017: Proceedings from the International Thermal Spray Conference, 520-524, June 7–9, 2017,
... profile of coatings. We have investigated the influence of expansion ratio, nozzle total length and the ratio of nozzle length of divergent section and parallel section of rectangular nozzle on behaviours of gas and particle by the computational fluid dynamics (CFD) in high pressure cold spraying...
Abstract
View Papertitled, Spray Pattern and Microstructure of Copper Coatings with the Optimized Rectangular Cross-Section Nozzle by the <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> (CFD) in High-Pressure Cold Spraying
View
PDF
for content titled, Spray Pattern and Microstructure of Copper Coatings with the Optimized Rectangular Cross-Section Nozzle by the <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> (CFD) in High-Pressure Cold Spraying
In the cold spray process, cross-sectional shape of the nozzle has a significant effect on spray pattern of coatings. There is a rectangular and a circular cross-sectional shapes on the cold spray nozzle. It has been reported that the rectangular nozzle provide a more uniform particle velocity across the exit of the nozzle. The circular exit nozzle is parabolic in shape. So spray pattern with the rectangular nozzle is wider than that with the circular spray nozzle. The goal of this investigation is to establish a design for the cold spray gun nozzle in order to gain more uniform spray profile of coatings. We have investigated the influence of expansion ratio, nozzle total length and the ratio of nozzle length of divergent section and parallel section of rectangular nozzle on behaviours of gas and particle by the computational fluid dynamics (CFD) in high pressure cold spraying. In this study, the spray pattern and microstructure of copper coatings with the rectangular cross-section nozzle optimized by CFD analysis in high-pressure cold spraying are reported. The optimized rectangular nozzle provide a more uniform spray profile of coatings. Relatively finer powder tended to deposit on the end of the coating.
Proceedings Papers
On the Validity of Continuum Computational Fluid Dynamics Approach in Very Low Pressure Plasma Spray Conditions
Available to Purchase
ITSC 2017, Thermal Spray 2017: Proceedings from the International Thermal Spray Conference, 754-760, June 7–9, 2017,
... code). It also shows how presence of flow gradients can contribute to the errors in the results for typical PS-PVD conditions. computational fluid dynamics microstructure plasma spray physical vapor deposition thermodynamic properties Thermal Spray 2017: Proceedings from the International...
Abstract
View Papertitled, On the Validity of Continuum <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Approach in Very Low Pressure Plasma Spray Conditions
View
PDF
for content titled, On the Validity of Continuum <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Approach in Very Low Pressure Plasma Spray Conditions
Plasma Spray Physical Vapor Deposition aims to substantially evaporate a powder in order to produce coatings with microstructures ranging from lamellar to columnar. This is achieved by the deposition of fine melted powder particles and nanoclusters and/or vapor condensation. The deposition process typically operates at pressure ranging between 10 and 200 Pa. In addition to experimental works, numerical works help to better understand the process and optimize the experimental conditions. However, the combination of high temperature and low pressure with the appearance of shock waves resulting from the supersonic expansion of the hot gas in the low pressure medium, makes questionable the suitability of the continuum approach for modelling such a process. This work deals with the study of (i) the effect of the pressure dependence of the thermodynamic and transport properties on the CFD predictions and (ii) the validity of the continuum approach for thermal plasma flow simulation under very low pressure conditions. It compares the flow fields predicted with a continuum approach (ANSYS Fluent CFD code) and a kinetic-based approach using a Direct Simulation Monte Carlo method (DSMC, SPARTA code). It also shows how presence of flow gradients can contribute to the errors in the results for typical PS-PVD conditions.
Proceedings Papers
ITSC2025, Thermal Spray 2025: Proceedings from the International Thermal Spray Conference, 7-14, May 5–8, 2025,
... nozzle type, four geometrical variables were investigated to reveal their individual and possibly combined potential to improve particle impact velocities. aerosol deposition computational fluid dynamics ceramic powders spray nozzles geometry particle velocity Thermal Spray 2025...
Abstract
View Papertitled, The Influence of Nozzle Geometry on Aerosol Deposition Studied Using 3D <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Simulations
View
PDF
for content titled, The Influence of Nozzle Geometry on Aerosol Deposition Studied Using 3D <span class="search-highlight">Computational</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamics</span> Simulations
This paper investigates three different types of nozzle geometries and the first steps for individual shape optimization to maximize the powder impact velocities. The basic types concern (i) a convergent, (ii) a convergent-divergent, and (iii) a convergent-constant geometry. For each nozzle type, four geometrical variables were investigated to reveal their individual and possibly combined potential to improve particle impact velocities.
Proceedings Papers
Taguchi Design and Analysis of 3D-Computer Fluid Dynamic (CFD) Experiments (TDACE) for the Optimization of Air-Cap Configuration in Arc Spraying
Available to Purchase
ITSC 2015, Thermal Spray 2015: Proceedings from the International Thermal Spray Conference, 695-702, May 11–14, 2015,
... Abstract The computational fluid dynamic approach is adopted in this work, using L16-Taguchi matrix, to study the effect of different secondary atomization gas outlet configurations on the gas velocity, jet divergence, and pressure distribution at cap outlet. The spraying process variables...
Abstract
View Papertitled, Taguchi Design and Analysis of 3D-<span class="search-highlight">Computer</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamic</span> (CFD) Experiments (TDACE) for the Optimization of Air-Cap Configuration in Arc Spraying
View
PDF
for content titled, Taguchi Design and Analysis of 3D-<span class="search-highlight">Computer</span> <span class="search-highlight">Fluid</span> <span class="search-highlight">Dynamic</span> (CFD) Experiments (TDACE) for the Optimization of Air-Cap Configuration in Arc Spraying
The computational fluid dynamic approach is adopted in this work, using L16-Taguchi matrix, to study the effect of different secondary atomization gas outlet configurations on the gas velocity, jet divergence, and pressure distribution at cap outlet. The spraying process variables that are integrated in this study are primary and secondary atomization gas pressure, PG and SG respectively. In addition, the geometrical variables of the SG air-cap like the position, the number and the angle of the outlet holes for SG are a part of the L16-Taguchi matrix. The effect of the process variables and geometrical design variations are analyzed on the obtained gas flow characteristics. Increasing the number of the SG outlet holes leads to a higher gas velocity at the cap outlet. The amount and the angle of the SG outlet holes have a direct effect on the plume divergence. The SG outlet angle determines the distance between the flow intersection point (PG-flow and SG-flow) and the air-cap outlet. Increasing the SG outlet angle leads to a reduction of the gas velocity. The use of Design of Experiment (DoE) in the optimization of the air-cap design by implementing CFD-simulation was proved to be a very useful and efficient tool to design high performance air-caps of twin-wire arc-spraying.
Proceedings Papers
Homogenization of Coating Properties in Atmospheric Plasma Spraying – Current Results of a DFG (German Research Foundation)-Funded Research Group
Available to Purchase
ITSC 2010, Thermal Spray 2010: Proceedings from the International Thermal Spray Conference, 533-538, May 3–5, 2010,
... of this research group is to adjust these properties systematically. A numerical model that couples fluid dynamic, electro-magnetic and thermal phenomena for a three-cathode torch was developed to investigate the plasma and the electric arc behaviour inside the torch. With help of self-developed computer...
Abstract
View Papertitled, Homogenization of Coating Properties in Atmospheric Plasma Spraying – Current Results of a DFG (German Research Foundation)-Funded Research Group
View
PDF
for content titled, Homogenization of Coating Properties in Atmospheric Plasma Spraying – Current Results of a DFG (German Research Foundation)-Funded Research Group
In the area of atmospheric plasma spraying, newly-developed triple-cathode technologies offer the potential to homogenize the coating properties with respect to porosity and residual stresses. Focused on numerical simulation, combined with advanced diagnostics, the goal of this research group is to adjust these properties systematically. A numerical model that couples fluid dynamic, electro-magnetic and thermal phenomena for a three-cathode torch was developed to investigate the plasma and the electric arc behaviour inside the torch. With help of self-developed computer tomography equipment, which is based on emission spectroscopy, combined with the solution of the Saha equation in thermodynamical equilibrium, it is now possible to reconstruct the 3- dimensional temperature distribution close to the torch outlet. This measurement allows us to confirm the torch numerical modelling. Coating formation is simulated by coupled computational fluid dynamics (CFD) and FEM simulation, so that fluid structure interaction is taken into account. This innovative approach has the advantage to predict residual stresses which occur during cooling and moreover the shrinking effects can be considered. By simulation of the individual regions, in combination with experimental results, which also include the particle velocity, diameter and surface temperature, the corresponding process parameters can be obtained for the desired coating properties.
Proceedings Papers
Simulation of PYSZ-Particles Impact and Solidification in Atmospheric Plasma Spraying Coating Process
Available to Purchase
ITSC 2008, Thermal Spray 2008: Proceedings from the International Thermal Spray Conference, 548-552, June 2–4, 2008,
..., heat transfer and solidification during the particle impact were performed using computational fluid dynamics. Tracing of free surfaces determinates volume of fluid method. Heat flux at the particle-substrate interface and temperature dependent liquid phase viscosity of PYSZ are studied and discussed...
Abstract
View Papertitled, Simulation of PYSZ-Particles Impact and Solidification in Atmospheric Plasma Spraying Coating Process
View
PDF
for content titled, Simulation of PYSZ-Particles Impact and Solidification in Atmospheric Plasma Spraying Coating Process
In this work numerical simulation results of the impact and solidification of molten PYSZ-particles on flat and rough substrate surfaces are presented. This investigation deals with the effect of the particle state prior impact, particle diameter and substrate roughness, on splats spreading behaviour and final morphology. The particles have a diameter range between 20 – 60 µm. Particle initial conditions prior to impact: speed, temperature and melting state, are taken from previous simulation modelling approaches of particle accelerating and heating. Simulations of fluid dynamics, heat transfer and solidification during the particle impact were performed using computational fluid dynamics. Tracing of free surfaces determinates volume of fluid method. Heat flux at the particle-substrate interface and temperature dependent liquid phase viscosity of PYSZ are studied and discussed. Simulated splat morphologies are compared with experimentally obtained splats.
Proceedings Papers
Influence of Injector Geometry on Particle Trajectories: Analysis of Particle Dynamics in the Injector and Plasma Jet
Available to Purchase
ITSC1998, Thermal Spray 1998: Proceedings from the International Thermal Spray Conference, 887-894, May 25–29, 1998,
... and mixing of the carrier-gas flow with the plasma jet was carried out using a 3-D computational fluids dynamics code. computational fluid dynamics gas mass flow rate injector geometry particle dynamics plasma jet Thermal Spray: Meeting the Challenges of the 21st Century: Copyright © 1998 ASM...
Abstract
View Papertitled, Influence of Injector Geometry on Particle Trajectories: Analysis of Particle <span class="search-highlight">Dynamics</span> in the Injector and Plasma Jet
View
PDF
for content titled, Influence of Injector Geometry on Particle Trajectories: Analysis of Particle <span class="search-highlight">Dynamics</span> in the Injector and Plasma Jet
The conditions of particle injection into the side of plasma jets play an important role in determining the microstructure and properties of sprayed deposits. However, few investigations have been carried out on this topic. The current work presents the results of an experimental and computational study of the influence of injector geometry and gas mass flow rate on particle dynamics at injector exit and in the plasma jet. Two injector geometries were tested: a straight tube and a curved tube with various radii of curvature. Zirconia powders with different particle size range and morphology were used. A possible size segregation effect in the injector was analyzed from the space distribution of particles collected on a stick tape. The spray pattern in the plasma jet was monitored from the thermal radiation emitted by particles. An analysis of the particle behavior in the injector and mixing of the carrier-gas flow with the plasma jet was carried out using a 3-D computational fluids dynamics code.
Proceedings Papers
Numerical Modeling of Particle Laden Flow in HVOF Torch with Gas Shroud
Available to Purchase
ITSC2000, Thermal Spray 2000: Proceedings from the International Thermal Spray Conference, 105-113, May 8–11, 2000,
... Abstract A particle laden flow in an HVOF torch is analyzed using Computational Fluid Dynamics (CFD). The torch is similar to the DJ Metco torch with a converging-diverging (de Laval) nozzle, where particles are injected through the center together with nitrogen as a carrier gas. The Eulerian...
Abstract
View Papertitled, Numerical Modeling of Particle Laden Flow in HVOF Torch with Gas Shroud
View
PDF
for content titled, Numerical Modeling of Particle Laden Flow in HVOF Torch with Gas Shroud
A particle laden flow in an HVOF torch is analyzed using Computational Fluid Dynamics (CFD). The torch is similar to the DJ Metco torch with a converging-diverging (de Laval) nozzle, where particles are injected through the center together with nitrogen as a carrier gas. The Eulerian formulation is used for the gas flow whereas the particle motion is described by using the Lagrangian formulation. The flow turbulence is modeled via k-e model with standard wall functions. For modeling the combustion process in the torch, a multi-reaction Eddy-Dissipation Model (EDM) is employed. The computational domain comprised the torch itself and the region outside the torch where our attention is mainly focused. The computations are performed for the torch with and without the gas shroud attachment. The results showed that the presence of the shroud affected to some degree the flow and temperature fields of the main gas and the particle stream, while at the same time, significantly reducing the entrainment of ambient air into the main stream as shown by the lower oxygen concentrations. The results of the numerical computations are compared with experimental results for the same operating conditions and the agreement is found to be good.
Proceedings Papers
Computational Modelling of a Thermo-Aabrasive Blasting Gun
Available to Purchase
ITSC 2005, Thermal Spray 2005: Proceedings from the International Thermal Spray Conference, 1306-1310, May 2–4, 2005,
... with computational fluid dynamic software, namely STAR-CD. The developed computational model can be applied to HVAF systems used for thermo-abrasive blasting and thermal spraying. computational modeling high-velocity air-fuel spray coating thermo-abrasive blasting gun Thermal Spray 2005: Proceedings from...
Abstract
View Papertitled, <span class="search-highlight">Computational</span> Modelling of a Thermo-Aabrasive Blasting Gun
View
PDF
for content titled, <span class="search-highlight">Computational</span> Modelling of a Thermo-Aabrasive Blasting Gun
In the last few years, a new method for surface preparation has evolved, namely thermo-abrasive blasting. This technique utilises a high enthalpy thermal jet to propel abrasive particles. The thermo-abrasive blasting gun, also called a thermal gun, is based on the principles of High Velocity Air Fuel (HVAF) processes. Some empirical data is available on thermo-abrasive blasting method and systems. To effectively improve on nozzle design and productivity, modelling of the thermo-abrasive blasting process was required. This paper describes the computational modelling of the thermal gun with computational fluid dynamic software, namely STAR-CD. The developed computational model can be applied to HVAF systems used for thermo-abrasive blasting and thermal spraying.
Proceedings Papers
Modeling of the Substrate Temperature Evolution during the APS Thermal Spray Process
Available to Purchase
ITSC 2003, Thermal Spray 2003: Proceedings from the International Thermal Spray Conference, 949-954, May 5–8, 2003,
... is taken into account using a computational fluid dynamic model describing the impact of the plasma jet on the substrate. For this part of the work, a two-layer extension to the Chen-Kim k-s model was used allowing the description of both the turbulent plasma jet and that of the flow in the viscous sub...
Abstract
View Papertitled, Modeling of the Substrate Temperature Evolution during the APS Thermal Spray Process
View
PDF
for content titled, Modeling of the Substrate Temperature Evolution during the APS Thermal Spray Process
A numerical model is presented for the computation of heat transfers during the APS thermal spray process. This model includes the contributions of both the impinging plasma jet and that of the particle flux on the substrate heating. The contribution of the impinging plasma jet is taken into account using a computational fluid dynamic model describing the impact of the plasma jet on the substrate. For this part of the work, a two-layer extension to the Chen-Kim k-s model was used allowing the description of both the turbulent plasma jet and that of the flow in the viscous sub-layer formed on the substrate surface. The contribution of the sprayed particles is taken into account considering their distribution in the spray jet. Since this is an important parameter that could affect the model accuracy, measurements of the deposit thickness profiles were first performed using the non-destructive acoustic microscopy method and the corresponding particle flux distribution was then deduced. Heat transfers inside the substrate were then computed using a three dimensional in-house code based on a finite volume approach. In the case studied, the results show that the contribution of the sprayed particles forming the coating is much more focalized than that of the plasma flow itself whereas the substrate nature has a strong influence on the thermal flux dissipation (not presented in the following). These elements are expected to provide useful information concerning the coating adhesion mechanisms and the formation of residual stresses during the coating elaboration.
Proceedings Papers
Investigation on the Effect of Helium-to-Nitrogen Ratio as Propellant Gas Mixture on the Processing of Titanium Coating using Cold Gas Dynamic Spray
Available to Purchase
ITSC 2011, Thermal Spray 2011: Proceedings from the International Thermal Spray Conference, 66-71, September 27–29, 2011,
... velocity. Velocity data were used to validate a computational fluid dynamic model. The numerical solution of the flow inside the nozzle was obtained from the Euler equations for the various He to N 2 concentrations. Particle tracking was carried out by using the computed distribution of density, Mach...
Abstract
View Papertitled, Investigation on the Effect of Helium-to-Nitrogen Ratio as Propellant Gas Mixture on the Processing of Titanium Coating using Cold Gas <span class="search-highlight">Dynamic</span> Spray
View
PDF
for content titled, Investigation on the Effect of Helium-to-Nitrogen Ratio as Propellant Gas Mixture on the Processing of Titanium Coating using Cold Gas <span class="search-highlight">Dynamic</span> Spray
This paper reports on the influence of the He to N 2 ratio on the properties of low pressure cold sprayed titanium coatings and on the characteristics of the generated supersonic two-phase flow. Experiments were carried out varying the He to N 2 concentration ranging from pure He to pure N 2 . Samples were characterized by their microstructural properties (i.e. microhardness and porosity). Deposition rate was evaluated and particle velocities were measured for all conditions. Deposition efficiency, coating density, and microhardness were found to be a function of particle impact velocity. Velocity data were used to validate a computational fluid dynamic model. The numerical solution of the flow inside the nozzle was obtained from the Euler equations for the various He to N 2 concentrations. Particle tracking was carried out by using the computed distribution of density, Mach number, temperature, viscosity, and a second order Runge-Kutta scheme. In addition, mean particle velocities at the exit of the nozzle were determined. Computed velocities were found to be in good agreement with measured ones. The model was then used to calculate nozzle dimensions that would maximize particle velocity. Optimized dimensions are proposed.
Proceedings Papers
Numerical Simulation of the Cold Gas Dynamic Spray Process
Available to Purchase
ITSC 2006, Thermal Spray 2006: Proceedings from the International Thermal Spray Conference, 191-196, May 15–18, 2006,
... Abstract A computational fluid dynamic (CFD) model of the cold gas dynamic spray process is presented. The gas dynamic flow field and particle trajectories within an oval shaped supersonic nozzle as well as in the immediate surroundings of the nozzle exit, before and after the impact...
Abstract
View Papertitled, Numerical Simulation of the Cold Gas <span class="search-highlight">Dynamic</span> Spray Process
View
PDF
for content titled, Numerical Simulation of the Cold Gas <span class="search-highlight">Dynamic</span> Spray Process
A computational fluid dynamic (CFD) model of the cold gas dynamic spray process is presented. The gas dynamic flow field and particle trajectories within an oval shaped supersonic nozzle as well as in the immediate surroundings of the nozzle exit, before and after the impact with the target plane, are simulated. Predicted nozzle wall pressure values compare well with experiment. In addition, predicted particle velocity results at the nozzle exit are in qualitative agreement with those obtained using a side-scatter laser Doppler anemometer (LDA.) Details of the pattern of particle release into the surroundings are visualized in a convenient manner.
Proceedings Papers
Numerical Simulation of Droplet Impact on Patterned Surfaces
Available to Purchase
ITSC 2007, Thermal Spray 2007: Proceedings from the International Thermal Spray Conference, 213-218, May 14–16, 2007,
... of the final splat, as well as the pore creation beneath the material. The simulations were performed using a computational fluid dynamic software, Simulent Drop, The code uses a three-dimensional finite difference algorithm solving full Navier Stokes Equation with heat transfer and phase change. Volume...
Abstract
View Papertitled, Numerical Simulation of Droplet Impact on Patterned Surfaces
View
PDF
for content titled, Numerical Simulation of Droplet Impact on Patterned Surfaces
In this work we present the numerical simulation results for the molten nickel and zirconia (YZS) droplets impact on different micro-scale patterned surfaces of silicon. The numerical simulation clearly showed the effect of surface roughness and the solidification on the shape of the final splat, as well as the pore creation beneath the material. The simulations were performed using a computational fluid dynamic software, Simulent Drop, The code uses a three-dimensional finite difference algorithm solving full Navier Stokes Equation with heat transfer and phase change. Volume of fluid (VOF) tracking algorithm is used to track the droplet free surface. Thermal contact resistance at the droplet– substrate interface is also included in the model. Specific attention is paid to the simulation of droplet impact under plasma spraying conditions. The droplet sizes ranged from 15 to 60 microns with the initial velocities of 70-250 m/s. The substrate surface was patterned by a regular array of cubes spaced at 1 µm and 5 µm from each other. The peak to valley height of each cube was between 1 to 3 µm. Different splat morphologies will be compared with those obtained from the experimental results under the same impact and surface conditions.
Proceedings Papers
A CFD Analysis of the Relationships between Process Parameters and Particle In-flight Characteristics in Flame Spraying
Available to Purchase
ITSC 2004, Thermal Spray 2004: Proceedings from the International Thermal Spray Conference, 796-799, May 10–12, 2004,
... Abstract The flame spraying process has been analysed using three-dimensional Computational Fluid Dynamics (CFD) simulations. The process employed at the Volvo Aero Corporation for the coating of fan and compressor housings has been modelled. The gas combustion was simulated as a multi...
Abstract
View Papertitled, A CFD Analysis of the Relationships between Process Parameters and Particle In-flight Characteristics in Flame Spraying
View
PDF
for content titled, A CFD Analysis of the Relationships between Process Parameters and Particle In-flight Characteristics in Flame Spraying
The flame spraying process has been analysed using three-dimensional Computational Fluid Dynamics (CFD) simulations. The process employed at the Volvo Aero Corporation for the coating of fan and compressor housings has been modelled. The gas combustion was simulated as a multi-component chemically reacting flow. The standard, two equations, k-ε turbulence model was employed. A statistical analysis of the computer simulation experiments revealed that particle velocity and particle temperature were dependent on four process parameters, namely the acetylene flow rate, the carrier gas flow, the powder feed rate and the spray distance. The most important factors influencing particle velocity and temperature were the acetylene flow rate and the carrier gas flow. The carrier gas flow rate was shown to have an unexpectedly large influence on particle in-flight properties. Simulations were repeated with particles of different median diameters. The study revealed that a very high correlation existed between particle temperature and particle velocity for particles of the same median diameter. Furthermore, the particle median diameter, when compared with the investigated process parameters, was found to have a more pronounced influence on both particle temperature and velocity. It would appear that the use of powder lots comprised of sufficiently fine-grained powders is the most promising single contribution towards increasing deposition efficiency that can be applied to the current process.
Proceedings Papers
Homogenization of Coating Properties in Three-Cathode Atmospheric Plasma Spraying by Use of Advanced Diagnostics and Numerical Simulation—Investigations of Suspension Plasma Spraying (SPS)
Available to Purchase
ITSC 2015, Thermal Spray 2015: Proceedings from the International Thermal Spray Conference, 452-459, May 11–14, 2015,
... of plasma and suspension behavior through diagnostic methods such as computer tomography and particle image velocimetry, and the analysis of coating formation through computational fluid dynamics and finite element analysis. The results of their investigations are presented, including tomographic...
Abstract
View Papertitled, Homogenization of Coating Properties in Three-Cathode Atmospheric Plasma Spraying by Use of Advanced Diagnostics and Numerical Simulation—Investigations of Suspension Plasma Spraying (SPS)
View
PDF
for content titled, Homogenization of Coating Properties in Three-Cathode Atmospheric Plasma Spraying by Use of Advanced Diagnostics and Numerical Simulation—Investigations of Suspension Plasma Spraying (SPS)
This paper discusses a research project with the goal of homogenizing the properties of three-cathode plasma sprayed coatings through the use of advanced diagnostics and numerical simulations. The approach included the development of a suspension injection setup, the determination of plasma and suspension behavior through diagnostic methods such as computer tomography and particle image velocimetry, and the analysis of coating formation through computational fluid dynamics and finite element analysis. The results of their investigations are presented, including tomographic reconstructions of temperature distribution, suspension behavior measurements, and coating analysis. The paper concludes with a discussion of the future directions of their research and the potential impact on the field of thermal spray coatings.
1