The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Jingzhou Zhao - One of the best experts on this subject based on the ideXlab platform.
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Control of Fluid Dynamics by nanoparticles in laser melting
Journal of Applied Physics, 2015Co-Authors: Chao Ma, Lianyi Chen, Jiaquan Xu, Jingzhou Zhao, Xiaochun LiAbstract:Effective control of Fluid Dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control Fluid Dynamics. In this study, laser melting was used to investigate the feasibility of tuning Fluid Dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the Fluid Dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the Fluid Dynamics. Characterizations of surface topographies and microstructures of pure Ni and Ni/Al2O3 nanocomposite were carried out before and after laser melting. The surface roughness of the Ni/Al2O3 nanocomposite sample was reduced significantly by laser melting, which broke the existing limit of laser surface polishing of pure Ni. It is believed that the n...
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Control of Fluid Dynamics by nanoparticles in laser melting
Journal of Applied Physics, 2015Co-Authors: Lianyi Chen, Jingzhou ZhaoAbstract:Effective control of Fluid Dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control Fluid Dynamics. In this study, laser melting was used to investigate the feasibility of tuning Fluid Dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the Fluid Dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the Fluid Dynamics. Characterizations of surface topographies and microstructures of pure Ni and Ni/Al2O3 nanocomposite were carried out before and after laser melting. The surface roughness of the Ni/Al2O3 nanocomposite sample was reduced significantly by laser melting, which broke the existing limit of laser surface polishing of pure Ni. It is believed that the nanoparticles increased the viscosity of the molten metal, thereby enhancing the viscous damping of the capillary oscillations in the melt pool, to produce a much smoother surface. Moreover, the experimental study also revealed that the viscosity enhancement by the nanoparticles effectively suppressed the thermocapillary flows which would introduce artificial asperities on a surface. The experimental results suggest that nanoparticles are effective in controlling melt pool Dynamics and overcoming the existing limits of laser processing. The new methodology, Fluid Dynamics control by nanoparticles, opens a new pathway to enrich liquid based processes for broad applications.
Lianyi Chen - One of the best experts on this subject based on the ideXlab platform.
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Control of Fluid Dynamics by nanoparticles in laser melting
Journal of Applied Physics, 2015Co-Authors: Chao Ma, Lianyi Chen, Jiaquan Xu, Jingzhou Zhao, Xiaochun LiAbstract:Effective control of Fluid Dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control Fluid Dynamics. In this study, laser melting was used to investigate the feasibility of tuning Fluid Dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the Fluid Dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the Fluid Dynamics. Characterizations of surface topographies and microstructures of pure Ni and Ni/Al2O3 nanocomposite were carried out before and after laser melting. The surface roughness of the Ni/Al2O3 nanocomposite sample was reduced significantly by laser melting, which broke the existing limit of laser surface polishing of pure Ni. It is believed that the n...
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Control of Fluid Dynamics by nanoparticles in laser melting
Journal of Applied Physics, 2015Co-Authors: Lianyi Chen, Jingzhou ZhaoAbstract:Effective control of Fluid Dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control Fluid Dynamics. In this study, laser melting was used to investigate the feasibility of tuning Fluid Dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the Fluid Dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the Fluid Dynamics. Characterizations of surface topographies and microstructures of pure Ni and Ni/Al2O3 nanocomposite were carried out before and after laser melting. The surface roughness of the Ni/Al2O3 nanocomposite sample was reduced significantly by laser melting, which broke the existing limit of laser surface polishing of pure Ni. It is believed that the nanoparticles increased the viscosity of the molten metal, thereby enhancing the viscous damping of the capillary oscillations in the melt pool, to produce a much smoother surface. Moreover, the experimental study also revealed that the viscosity enhancement by the nanoparticles effectively suppressed the thermocapillary flows which would introduce artificial asperities on a surface. The experimental results suggest that nanoparticles are effective in controlling melt pool Dynamics and overcoming the existing limits of laser processing. The new methodology, Fluid Dynamics control by nanoparticles, opens a new pathway to enrich liquid based processes for broad applications.
Srdjan Nesic - One of the best experts on this subject based on the ideXlab platform.
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Using computational Fluid Dynamics in combating erosion–corrosion
Chemical Engineering Science, 2006Co-Authors: Srdjan NesicAbstract:Computational Fluid Dynamics was used to search for the links between the observed pattern of attack seen in a bauxite refinery's heat exchanger headers and the hydroDynamics inside the header. Validation of the computational Fluid Dynamics results was done by comparing then with flow parameters measured in a 1:5 scale model of the first pass header in the laboratory. Computational Fluid Dynamics simulations were used to establish hydrodynamic similarity between the 1:5 scale and full scale models of the first pass header. It was found that the erosion-corrosion damage seen at the tubesheet of the first pass header was a consequence of increased levels of turbulence at the tubesheet caused by a rapidly turning flow. A prismatic flow corrections device introduced in the past helped in rectifying the problem at the tubesheet but exaggerated the erosion-corrosion problem at the first pass header shell. A number of alternative flow correction devices were tested using computational Fluid Dynamics. Axial ribbing in the first pass header and an inlet flow diffuser have shown the best performance and were recommended for implementation. Computational Fluid Dynamics simulations have revealed a smooth orderly low turbulence flow pattern in the second, third and fourth pass as well as the exit headers where no erosion-corrosion was seen in practice. This study has confirmed that near-wall turbulence intensity, which can be successfully predicted by using computational Fluid Dynamics, is a good hydrodynamic predictor of erosion-corrosion damage in complex geometries. (c) 2006 Published by Elsevier Ltd.
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Using computational Fluid Dynamics in combating erosion-corrosion
Chemical Engineering Science, 2006Co-Authors: Srdjan NesicAbstract:Computational Fluid Dynamics was used to search for the links between the observed pattern of attack seen in a bauxite refinery's heat exchanger headers and the hydroDynamics inside the header. Validation of the computational Fluid Dynamics results was done by comparing then with flow parameters measured in a 1:5 scale model of the first pass header in the laboratory. Computational Fluid Dynamics simulations were used to establish hydrodynamic similarity between the 1:5 scale and full scale models of the first pass header. It was found that the erosion-corrosion damage seen at the tubesheet of the first pass header was a consequence of increased levels of turbulence at the tubesheet caused by a rapidly turning flow. A prismatic flow corrections device introduced in the past helped in rectifying the problem at the tubesheet but exaggerated the erosion-corrosion problem at the first pass header shell. A number of alternative flow correction devices were tested using computational Fluid Dynamics. Axial ribbing in the first pass header and an inlet flow diffuser have shown the best performance and were recommended for implementation. Computational Fluid Dynamics simulations have revealed a smooth orderly low turbulence flow pattern in the second, third and fourth pass as well as the exit headers where no erosion-corrosion was seen in practice. This study has confirmed that near-wall turbulence intensity, which can be successfully predicted by using computational Fluid Dynamics, is a good hydrodynamic predictor of erosion-corrosion damage in complex geometries. (c) 2006 Published by Elsevier Ltd.
Xiaochun Li - One of the best experts on this subject based on the ideXlab platform.
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Control of Fluid Dynamics by nanoparticles in laser melting
Journal of Applied Physics, 2015Co-Authors: Chao Ma, Lianyi Chen, Jiaquan Xu, Jingzhou Zhao, Xiaochun LiAbstract:Effective control of Fluid Dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control Fluid Dynamics. In this study, laser melting was used to investigate the feasibility of tuning Fluid Dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the Fluid Dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the Fluid Dynamics. Characterizations of surface topographies and microstructures of pure Ni and Ni/Al2O3 nanocomposite were carried out before and after laser melting. The surface roughness of the Ni/Al2O3 nanocomposite sample was reduced significantly by laser melting, which broke the existing limit of laser surface polishing of pure Ni. It is believed that the n...
Chao Ma - One of the best experts on this subject based on the ideXlab platform.
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Control of Fluid Dynamics by nanoparticles in laser melting
Journal of Applied Physics, 2015Co-Authors: Chao Ma, Lianyi Chen, Jiaquan Xu, Jingzhou Zhao, Xiaochun LiAbstract:Effective control of Fluid Dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control Fluid Dynamics. In this study, laser melting was used to investigate the feasibility of tuning Fluid Dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the Fluid Dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the Fluid Dynamics. Characterizations of surface topographies and microstructures of pure Ni and Ni/Al2O3 nanocomposite were carried out before and after laser melting. The surface roughness of the Ni/Al2O3 nanocomposite sample was reduced significantly by laser melting, which broke the existing limit of laser surface polishing of pure Ni. It is believed that the n...
