Gatineau, Canada
Gatineau, Canada

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Assaad J.,University of Ottawa | Corbeil A.,Brayton Energy Canada | Richer P.F.,Brayton Energy Canada | Jodoin B.,University of Ottawa
Journal of Thermal Spray Technology | Year: 2011

This study examines the feasibility of using the pulsed gas dynamic spraying (PGDS) process to deposit metal powder on the outer surfaces of metal wire mesh wafers for use as high-performance compact heat exchangers. Plain-square weave woven mesh produced from stainless steel wires were stacked and sintered to form wire mesh bricks, which were then cut into wafers. The outer surfaces of the wafers were sealed using the PGDS deposition technique as opposed to the more traditional brazing sheet solution. This approach provides more intimate contact between the mesh wire tips and sealed surface, thereby promoting conduction through the outer walls and improving the heat exchanger efficiency. In addition, PGDS is an attractive alternative to brazing sheets for this application because of its potential for reduced manufacturing costs. Burst and tensile tests of the PGDS coated wafers were carried out. © ASM International.


Cormier Y.,University of Ottawa | Dupuis P.,University of Ottawa | Jodoin B.,University of Ottawa | Corbeil A.,Brayton Energy Canada
Journal of Thermal Spray Technology | Year: 2016

This work evaluates the thermal and hydrodynamic performance of pyramidal fin arrays produced using cold spray as an additive manufacturing process. Near-net-shaped pyramidal fin arrays of pure aluminum, pure nickel, and stainless steel 304 were manufactured. Fin array characterization such as fin porosity level and surface roughness evaluation was performed. The thermal conductivities of the three different coating materials were measured by laser flash analysis. The results obtained show a lower thermal efficiency for stainless steel 304, whereas the performances of the aluminum and nickel fin arrays are similar. This result is explained by looking closely at the fin and substrate roughness induced by the cold gas dynamic additive manufacturing process. The multi-material fin array sample has a better thermal efficiency than stainless steel 304. The work demonstrates the potential of the process to produce streamwise anisotropic fin arrays as well as the benefits of such arrays. © 2015, ASM International.


Cormier Y.,University of Ottawa | Dupuis P.,University of Ottawa | Jodoin B.,University of Ottawa | Corbeil A.,Brayton Energy Canada
Proceedings of the International Thermal Spray Conference | Year: 2015

This work studies the thermal and hydrodynamic performances of pyramidal fin arrays produced using the cold spray process as an additive manufacturing process. Near-net shaped pyramidal fin arrays of various materials were manufactured (pure aluminum, pure nickel and stainless steel 304). Fin array characterization such as fin porosity level and surface roughness evaluation was performed. The nickel pyramidal fin array is shown to be rougher compared to the two other materials used in this study. The results obtained show a lower thermal efficiency for stainless steel 304 whereas the performances of the aluminum and nickel fin arrays are similar. The multi-material sample has a better thermal efficiency than stainless steel 304, which constitutes the proof of concept of using a streamwise anisotropic fin array. © (2015) by ASM International All rights reserved.


Dupuis P.,University of Ottawa | Cormier Y.,University of Ottawa | Fenech M.,University of Ottawa | Corbeil A.,Brayton Energy Canada | Jodoin B.,University of Ottawa
International Journal of Heat and Mass Transfer | Year: 2016

The focus of this work is the identification and analysis of the flow structures found in pyramidal pin fin arrays produced using the Masked Cold Gas Dynamic Spraying (MCGDS) additive manufacturing process. The observed flow structures are described, with classic double recirculation patterns being identified. The turbulence intensity levels of the flow in the axial flow channels was measured and it was found that although the flow rates considered in this work correspond to low Reynolds numbers (500-3000), significant turbulence intensity levels are found. Furthermore, these levels increase as the flow progresses downstream, even though the large scale flow structures are well established after a few rows (as little as two in this case). A slight misalignment of the axial and transverse flow channels resulting from imperfections in the masks caused a bypass flow structure to arise in the wake of the pin fins, replacing the double recirculation pattern observed when there is no such misalignment. A CFD model was used to investigate the effect of these misalignments on heat transfer efficiency and predicted that there would be no significant effect in the configurations studied. Finally, this work shows the importance of not only considering the flow structures in the fin's wake, but also the effect of these structures on the turbulence levels of the axial flow channels, which could significantly affect the thermal and hydrodynamic performance. © 2015 Elsevier Ltd. All rights reserved.


Dupuis P.,University of Ottawa | Cormier Y.,University of Ottawa | Farjam A.,University of Ottawa | Jodoin B.,University of Ottawa | Corbeil A.,Brayton Energy Canada
International Journal of Heat and Mass Transfer | Year: 2014

Near-net pyramidal shaped fin arrays have been produced using the Cold Gas Dynamic Spraying (CGDS) process. Some fin arrays have been modified to trapezoid prism geometry by grinding the top of the pyramidal fins to study the effect of varying the base angle, at a constant fin height. All fin arrays have been tested for thermal and hydrodynamic performance. Little variation in thermal conductance between ground and as-sprayed fins is observed for the same fin heights, while a slightly more significant variation in pressure loss through the fin array is found. A comparison of these performances was performed with plain rectangular fins. The new fin geometry outperforms the traditional rectangular fins when comparing the thermal conductance per unit pumping power for a given heat exchanger volume over the range of Reynolds numbers studied. © 2013 Elsevier Ltd. All rights reserved.


Cormier Y.,University of Ottawa | Dupuis P.,University of Ottawa | Farjam A.,University of Ottawa | Corbeil A.,Brayton Energy Canada | Jodoin B.,University of Ottawa
International Journal of Heat and Mass Transfer | Year: 2014

This paper investigates the effects of varying the fin height and the fin density of pyramidal pin fins produced using cold spray technology. The thermal and hydrodynamic performance of this new type of fin array is evaluated using a forced convection heat transfer apparatus. The heat transfer efficiency of this type of extended surface is determined and correlations linking the Nusselt number, the Reynolds number, the fin height and the fin density are produced and validated. The geometric and thermo-hydraulic parameters affecting the thermal conductance of the pyramidal pin fin arrays are discussed. It is found that increasing either the fin height or the fin density also increases the total thermal conductance at the expense of a higher pressure loss. © 2014 Elsevier B.V. All rights reserved.


Cormier Y.,University of Ottawa | Dupuis P.,University of Ottawa | Jodoin B.,University of Ottawa | Corbeil A.,Brayton Energy Canada
Proceedings of the International Thermal Spray Conference | Year: 2013

This work studies the manufacturability of pyramidal fin arrays produced using the cold spray process. Near-net shaped pyramidal fin arrays of various sizes were manufactured. Fin array characterization was performed and heat transfer performance was assessed. Results obtained correlate with data published for banks of tubes with similar dimensionless pitch. A characteristic change in the performance slope at a critical Reynolds number is observed. The fins produced using the cold spray process outperform traditional straight-cut fins at the same fin density.


Cormier Y.,University of Ottawa | Dupuis P.,University of Ottawa | Jodoin B.,University of Ottawa | Corbeil A.,Brayton Energy Canada
Journal of Thermal Spray Technology | Year: 2013

This work explores the manufacturability of pyramidal fin arrays produced using the cold spray process. Near-net shaped pyramidal fin arrays of various sizes and fin densities were manufactured using masks made of commercially available steel wire mesh. The feedstock powders used to produce the fins are characterized using scanning electron microscopy. Obstruction of the masks was investigated. The standoff distances between the substrate, mesh, and nozzle were empirically determined. Fin array characterization was performed using digital microscopy. The fin arrays' heat transfer performance was assessed experimentally for a range of Reynolds number relevant to the application sought. The fins produced using the cold spray process outperform traditional straight (rectangular) fins at the same fin density and it is hypothesized that this is due to increased fluid mixing and turbulence. © 2013 ASM International.


Patent
Brayton Energy Canada | Date: 2010-05-04

A heat exchanger component is made by forming a wafer having a pair of opposed outer major faces with interstices between them from a stack of wire mesh screens. The outer major surfaces of the wafer are sealed by depositing a metal coating on them. The deposited metal coatings define between them a flow path for a heat exchange fluid extending through the interstices of the wafer.


Disclosed is a method and apparatus of fabricating three-dimensional heat transfer enhancing features on a surface of a substrate, the three-dimensional heat transfer enhancing features having a predetermined desired shape on a surface of a substrate. A mask is supplied, the mask having a pattern formed therein. The pattern is selected based on the predetermined desired shape of the three-dimensional heat transfer enhancing features to be fabricated. A jet of impinging coating particles is sprayed through the mask towards the substrate. A portion of the jet is selectively blocked with the pattern in the mask to fabricate the three-dimensional heat transfer enhancing features on the substrate.

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