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4624 |
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Tuesday, May 10, 2016, Room 3E 11:10 AM Process Diagnostics, Sensors & Controls |
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Particle in-flight velocity and dispersion measurements at increased particle feed rates in cold spray |
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Morten Meyer* / The University of Dublin, Ireland Shuo Yin / Department of Mechanical and Manufacturing Engineering, Trinity College, The University of Dublin, Ireland Rocco Lupoi/ Department of Mechanical and Manufacturing Engineering, Trinity College, The University of Dublin, Ireland |
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Cold Spray (CS) progressively attracts the interest of research and industry due to its rapid, solid-state particle deposition process and the respective advantages over conventional spray technologies. The acceleration of the particles is crucial to the efficiency of CS, and previous fluid dynamic investigations rarely consider the oftentimes low particle feed rate as an influential parameter for the acceleration. However, because higher particle loadings can have an increasingly important effect, the particle velocities in the jets of a low pressure and a high pressure CS system were measured at varying particle feed rates using Particle Image Velocimetry (PIV). The particle dispersion and velocity evolution along the jet axis were investigated for several differently shaped feedstock materials. It was found that the mean particle velocity noticeably decreases with increasing particulate loading in all cases, aggravated for lower working pressures. Moreover, the velocity distribution depends on the particle material, shape and size. The dispersion of particles was also observed to depend on the feed rate. Consequently, an increased particle feed rate affects the impact velocity and hence the efficiency of Cold Spray. Particularly computational modelling results neglecting this interconnection are required to be further improved based on similar experimental studies. |