Assessment of CFD Modeling via Flow Visualization in Cold Spray Process

Samareh, B.; Stier, O.; Lüthen, V.; Dolatabadi, Ali

doi:10.1007/s11666-009-9363-9

Cited by 74 publications

(33 citation statements)

References 13 publications

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“…Nevertheless, depending on the particle feed rate and the relative gas consumption, the discrete phase loading can increasingly affect the acceleration process at higher feed rate levels. Results demonstrated by Samareh et al [22] indicated that the gas flow structures change and the particle speed reduces as their mass fraction increases. Accordingly, a study by Lupoi [23] showed that a number of experimental observations with various nozzle geometries could not be explained by 1-way coupling CFD techniques.…”

Section: Introductionmentioning

confidence: 97%

Particle In-Flight Velocity and Dispersion Measurements at Increasing Particle Feed Rates in Cold Spray

2016

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Cold Spray (CS) is attracting the interest of research and industry due to its rapid, solid-state particle deposition process and the respective advantages over conventional deposition technologies. The acceleration of the particles is critical to the efficiency of CS, and previous fluid dynamic investigations rarely consider the particle feed rate important. However, because higher particle loadings are typically used in the process, the effect of this cannot be assumed negligible. This study therefore investigates the particle velocities in the supersonic jet of an advanced CS system at low and high pressure levels and varying particle feed rates using Particle Image Velocimetry (PIV). The particle dispersion and velocity evolution along the jet axis were investigated for several feedstock materials. It was found that the average particle velocity noticeably decreases with increasing particulate loading in all cases. This effect is aggravated for lower working pressures, but mainly depends on the feedstock material, which implies more complex, volume-fraction related physics playing a role in this respect. Moreover, the velocity distribution and particle dispersion were also observed to be influenced by the feed rate, depending on the particle material. Increased particle feed rates hence affect the magnitude and distribution of impact velocity and consequently the efficiency of CS. In particular, numerical models neglecting this interconnection are required to be further improved, based on these experimental studies.

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Section: Introductionmentioning

confidence: 97%

Particle In-Flight Velocity and Dispersion Measurements at Increasing Particle Feed Rates in Cold Spray

2016

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“…This makes further development of more advanced methods and their validation necessary. It could be suggested to make use of a Reynolds-stress model (RSM) that was successfully applied in CS applications in good agreement with experimental observations (Samareh et al, 2009).…”

Section: Coupled Simulationmentioning

confidence: 76%

“…A limit of this type of model is the dependency of its validity on relatively high particle density and uniform distribution. The same authors contributed with another publication (Samareh et al, 2009) that is focused on the simulation of the shock pattern in the jet using a two-way coupled Lagrangian approach. It was found that flow patterns could be predicted with high accuracy, including effects of high particle loading in the jet.…”

Section: Coupled Simulationmentioning

confidence: 99%

An analysis of the particulate flow in cold spray nozzles

Meyer

Lupoi

2015

Mech. Sci.

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Abstract. Cold Spray is a novel technology for the application of coatings onto a variety of substrate materials. In this method, melting temperatures are not crossed and the bonding is realized by the acceleration of powder particles through a carrier gas in a converging-diverging nozzle and their high energy impact over a substrate material. The critical aspect of this technology is the acceleration process and the multiphase nature of it. Three different nozzle designs were experimented under constant conditions and their performance simulated using Computational Fluid Dynamics tools. The Deposition Efficiency was measured using titanium as feedstock material and it was shown that it decreases with the cross-sectional throat area of the nozzle. Computational results based on a one-way coupled multiphase approach did not agree with this observation, while more sophisticated modelling techniques with two-way couplings can partially provide high-quality outcomes, in agreement with experimental data.

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“…Fluent (version 6.3.26) commercial software was used in this work to predict the performance of the Cold Spray nozzles analyzed, combined with a study of particles trajectories and velocity within the jet flow. Samareh et al [17] have studied through a two-way coupling system the behaviour of particles in CS nozzles and effects on gas velocity for high particle loadings (60 to 180g/min), and by implementing advanced multiple equations turbulence models. Such models can be accurate, but are relatively difficult to consistently converge up to higher order schemes; also the loading of particles within the carrier gas in most Cold Spray applications is typically smaller, therefore within the range of sufficiently diluted flow (solid phase volume fraction <10%) [12,18]; particle-particle and particle-carrier gas interactions can be negligible.…”

Section: Cfd Simulation Of Cold Spray Nozzlesmentioning

confidence: 99%

Powder stream characteristics in cold spray nozzles

Lupoi

O’Neill

2011

Surface and Coatings Technology

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Abstract. The exponential increase of industrial demand in the past two decades has led scientists to the development of alternative technologies for the fast manufacturing of engineering components, aside from standard and time consuming techniques such as casting or forging.Cold Spray (CS) is a newly developed manufacturing technique, based upon the deposition of metal powder on a substrate due to high energy particles impacts. In this process, the powder is accelerated up to considerable speed in a converging-diverging nozzle, typically using air, nitrogen or helium as a carrier gas. Recent developments have demonstrated significant process capabilities, from the building of mould-free 3D shapes made of various metals, to low porosity and corrosion resistant titanium coatings.In the CS process, the particle stream characteristics during the acceleration process is important in relation to the final geometry of the coating. Experimental studies have shown the tendency of particles to spread over the nozzle acceleration channel, resulting in a wide exit stream and in the difficulty of producing narrow tracks. This paper presents an investigation on the powder stream characteristics in CS supersonic nozzles. The powder insertion location was varied within the carrier gas flow, along with the geometry of the powder injector, in order to identify their relation 2 with particles trajectories. Computational Fluid Dynamic (CFD) results by Fluent v6.3.26 are presented, along with experimental observations. Different configurations were tested and modelled, giving deposited track geometries of copper and tin ranging from 1mm to 8mm in width on metal and polymer substrates.

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Assessment of CFD Modeling via Flow Visualization in Cold Spray Process

Cited by 74 publications

References 13 publications

Particle In-Flight Velocity and Dispersion Measurements at Increasing Particle Feed Rates in Cold Spray

Particle In-Flight Velocity and Dispersion Measurements at Increasing Particle Feed Rates in Cold Spray

An analysis of the particulate flow in cold spray nozzles

Powder stream characteristics in cold spray nozzles

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