The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
Jet Tseng - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Pin-fin and finned shape heat sink for power electronics in future aircraft
Applied Thermal Engineering, 2018Co-Authors: Assel Sakanova, Jet TsengAbstract:Abstract This study investigates the heat transfer performance of finned and Pin-fin heat sinks for high power density converter more-electric aircraft of the future. There is a lack of studies evaluating the cooling performance of Pin-fin as compared to that of the finned-type heat sink Configuration. The influence of various design aspects such as type of fluid flow (laminar or turbulent), type of working fluid (fuel or air) and geometry Configuration (Pin-fin or finned shaped heat sink) on heat transfer performance is compared. Circular, cone and hydrofoil Pin fin arrays have been considered. It is concluded that the thermal performance of Pin-fin heat sink is superior to the finned Configuration by 1.6–2 times in all cases except when fuel coolant is employed at turbulent type of flow. As weight of heat sink is concerned, the use of Pin-fin shape can reduce up to half of the weight of conventional finned heat sink. The results of this paper can provide the guidance to be applied when designing the heat sink for power electronics in future more-electric aircrafts.
Assel Sakanova - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Pin-fin and finned shape heat sink for power electronics in future aircraft
Applied Thermal Engineering, 2018Co-Authors: Assel Sakanova, Jet TsengAbstract:Abstract This study investigates the heat transfer performance of finned and Pin-fin heat sinks for high power density converter more-electric aircraft of the future. There is a lack of studies evaluating the cooling performance of Pin-fin as compared to that of the finned-type heat sink Configuration. The influence of various design aspects such as type of fluid flow (laminar or turbulent), type of working fluid (fuel or air) and geometry Configuration (Pin-fin or finned shaped heat sink) on heat transfer performance is compared. Circular, cone and hydrofoil Pin fin arrays have been considered. It is concluded that the thermal performance of Pin-fin heat sink is superior to the finned Configuration by 1.6–2 times in all cases except when fuel coolant is employed at turbulent type of flow. As weight of heat sink is concerned, the use of Pin-fin shape can reduce up to half of the weight of conventional finned heat sink. The results of this paper can provide the guidance to be applied when designing the heat sink for power electronics in future more-electric aircrafts.
Erich J. Windhab - One of the best experts on this subject based on the ideXlab platform.
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Experimental and computational study of a high speed Pin mixer via PEPT, visualization and CFD
Chemical Engineering Science, 2016Co-Authors: Anne Kathrin Konz, Erich J. WindhabAbstract:Abstract Continuous high speed Pin mixers have been successfully implemented industrially to mix high fractions of powders into highly viscous non-Newtonian liquids. However, they have not been described in the literature yet. This work presents a multi-method approach, consisting of conventional torque and throughput measurements to calculate average residence times and dimensionless Reynolds/power numbers for suspension mixing, Positron Emission Particle Tracking (PEPT) to gain information on particle trajectories and velocities in the investigated opaque model system, high speed film visualization and CFD simulations. By the combination of these methods, valuable information on the influence of variable process parameters, particularly on the influence of Pin Configuration, Pin shape and inclination of semi-cylindrical Pins on mixing mechanisms and efficiency, could be gathered for a broad range of viscosities and powder fractions in Newtonian and non-Newtonian fluids. Flow patterns such as a “Split-and-Recombine” convection pattern at the Pins, axial mixing mechanisms and beneficial process conditions to reduce particle sedimentation caused by centrifugal forces in the mixer were retrieved from the results. The PEPT methodology was successfully implemented for a high-shear continuous mixing process of suspensions for the first time. As the combined methodology shows reasonable and reliable results that were also applicable at industrial scale, the work provides sound basis for further research development of measurement techniques for other mixing processes, especially in opaque systems.
Anne Kathrin Konz - One of the best experts on this subject based on the ideXlab platform.
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Experimental and computational study of a high speed Pin mixer via PEPT, visualization and CFD
Chemical Engineering Science, 2016Co-Authors: Anne Kathrin Konz, Erich J. WindhabAbstract:Abstract Continuous high speed Pin mixers have been successfully implemented industrially to mix high fractions of powders into highly viscous non-Newtonian liquids. However, they have not been described in the literature yet. This work presents a multi-method approach, consisting of conventional torque and throughput measurements to calculate average residence times and dimensionless Reynolds/power numbers for suspension mixing, Positron Emission Particle Tracking (PEPT) to gain information on particle trajectories and velocities in the investigated opaque model system, high speed film visualization and CFD simulations. By the combination of these methods, valuable information on the influence of variable process parameters, particularly on the influence of Pin Configuration, Pin shape and inclination of semi-cylindrical Pins on mixing mechanisms and efficiency, could be gathered for a broad range of viscosities and powder fractions in Newtonian and non-Newtonian fluids. Flow patterns such as a “Split-and-Recombine” convection pattern at the Pins, axial mixing mechanisms and beneficial process conditions to reduce particle sedimentation caused by centrifugal forces in the mixer were retrieved from the results. The PEPT methodology was successfully implemented for a high-shear continuous mixing process of suspensions for the first time. As the combined methodology shows reasonable and reliable results that were also applicable at industrial scale, the work provides sound basis for further research development of measurement techniques for other mixing processes, especially in opaque systems.
Luís Augusto Rocha - One of the best experts on this subject based on the ideXlab platform.
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Tribocorrosion Studies in Centrifugally Cast Al-Matrix SiCp-reinforced Functionally Graded Composites
Materials Science Forum, 2004Co-Authors: Alexandre Velhinho, José D. Botas, E. Ariza, José R. B. Gomes, Luís Augusto RochaAbstract:The present work reports results obtained from a series of preliminary experiments aiming at complementing the current knowledge about the wear behaviour of centrifugally-cast FGM Al/SiCp composites, through concurrent corrosion processes. Precursor MMC's were prepared by rheocasting, using 118.8 µm SiC particles and an Al-10Si-2.2 Mg alloy. Those MMC's were then molten and centrifugally cast in order to produce cylindrical FGMMC's. Discs machined from the top surface of each sample were tested against nodular cast iron Pins, using an inverted Configuration Pin-on-disc tribometer. Sliding tests took place at room temperature, over a 50000 m sliding distance, with a sliding speed of 0.3 m s -1 , under a 5 N normal load; both dry-sliding and water-lubricated tests were performed. In order to elucidate the mechanisms involved, the wear coefficients were calculated for each condition, and the samples were subjected to morphological characterization via SEM/EDS. Concurrently, in the case of the water-lubrication tests, the corrosion potential of the tribological pair was monitored. The results obtained show an increase in material loss for the water-lubricated cases, although variations are registered depending on reinforcing particle volume fraction. At the same time, the open circuit potential response of the tribological pair may be correlated with the events of formation/destruction of the tribolayers.