The Experts below are selected from a list of 20454 Experts worldwide ranked by ideXlab platform
David Arnold - One of the best experts on this subject based on the ideXlab platform.
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particle laden thin film flow in helical channels with arbitrary shallow cross Sectional Shape
Physics of Fluids, 2019Co-Authors: David Arnold, Yvonne M. Stokes, J. E. F. GreenAbstract:Particle-laden flows in helical channels are of interest for their applications in spiral particle separators used in the mining and mineral processing industries. In this paper, we extend the previous work of Lee, Stokes, and Bertozzi [“Behaviour of a particle-laden flow in a spiral channel,” Phys. Fluids 26, 043302 (2014)] by studying thin-film flows of monodisperse particle-laden fluid in helically wound channels of arbitrary centerline curvature and torsion and arbitrary cross-Sectional Shape. In the case where the particles are uniformly distributed through the depth of the film, significant analytic progress can be made yielding insight into the influence of channel geometry on particle distribution across the channel cross section: the governing equations reduce to a single nonlinear ordinary differential equation, which is readily integrated numerically to obtain the solution subject to appropriate boundary conditions. Motivated by possible application to the design of spiral separators, we consider the effects of changing the channel centerline geometry, the cross-Sectional Shape and the particle density on the resulting flows, and the radial distribution of particles. Our results support the findings in the work of Arnold, Stokes, and Green [“Thin-film flow in helically wound rectangular channels of arbitrary torsion and curvature,” J. Fluid Mech. 764, 76–94 (2015)] regarding the effect of channel centerline geometry and cross-Sectional Shape on flows in particle-free regions. In particle-rich regions, similar effects are seen although the primary velocity is lower due to increased effective mixture viscosity. Of key interest is the effect of channel geometry on the focusing of the particles for given fluxes of fluid and particles. We find that introducing a trench into the channel cross section, a feature often used in commercial spiral particle separators, leads to a smaller radial width of the particle-rich region, i.e., sharper focusing of the particles, which is consistent with experiments showing that channel geometry influences particle separation in a spiral separator.Particle-laden flows in helical channels are of interest for their applications in spiral particle separators used in the mining and mineral processing industries. In this paper, we extend the previous work of Lee, Stokes, and Bertozzi [“Behaviour of a particle-laden flow in a spiral channel,” Phys. Fluids 26, 043302 (2014)] by studying thin-film flows of monodisperse particle-laden fluid in helically wound channels of arbitrary centerline curvature and torsion and arbitrary cross-Sectional Shape. In the case where the particles are uniformly distributed through the depth of the film, significant analytic progress can be made yielding insight into the influence of channel geometry on particle distribution across the channel cross section: the governing equations reduce to a single nonlinear ordinary differential equation, which is readily integrated numerically to obtain the solution subject to appropriate boundary conditions. Motivated by possible application to the design of spiral separators, we consid...
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Particle-laden thin-film flow in helical channels with arbitrary shallow cross-Sectional Shape
arXiv: Fluid Dynamics, 2019Co-Authors: David Arnold, Yvonne M. Stokes, J. E. F. GreenAbstract:Particle-laden flows in helical channels are of interest for their applications in spiral particle separators used in the mining and mineral processing industries. In this paper, we extend the previous work of Lee, Stokes, Bertozzi (2013) by studying thin-film flows of mono-disperse particle-laden fluid in helically-wound channels of arbitrary centreline curvature and torsion, and arbitrary cross-Sectional Shape. In the case where the particles are uniformly distributed through the depth of the film, significant analytic progress can be made: the governing equations reduce to a single nonlinear ordinary differential equation, which is readily integrated numerically to obtain the solution subject to appropriate boundary conditions. Motivated by possible application to the design of spiral separators, we consider the effects of changing the channel centreline geometry, the cross-Sectional Shape and the particle density on the resulting flows and the radial distribution of particles. Our results support the findings in Arnold, Stokes, Green (2016) regarding the effect of channel centreline geometry and cross-Sectional Shape on flows in particle-free regions. In particle-rich regions, similar effects are seen, although the primary velocity is lower due to increased effective mixture viscosity. \ys{Of key interest, is the effect of channel geometry on the focusing of the particles, for given fluxes of fluid and particles. We find that introducing a trench into the channel cross-section, a feature often used in commercial spiral particle separators, leads to smaller radial width of the particle-rich region, i.e. sharper focusing of the particles, which is consistent with experiments showing that channel geometry influences particle separation in a spiral separator.
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thin film flow in helically wound shallow channels of arbitrary cross Sectional Shape
Physics of Fluids, 2017Co-Authors: David Arnold, Y M Stokes, J. E. F. GreenAbstract:We consider the steady, gravity-driven flow of a thin film of viscous fluid down a helically wound shallow channel of arbitrary cross-Sectional Shape with arbitrary torsion and curvature. This extends our previous work [D. J. Arnold et al., “Thin-film flow in helically-wound rectangular channels of arbitrary torsion and curvature,” J. Fluid Mech. 764, 76–94 (2015)] on channels of rectangular cross section. The Navier-Stokes equations are expressed in a novel, non-orthogonal coordinate system fitted to the channel bottom. By assuming that the channel depth is small compared to its width and that the fluid depth in the vertical direction is also small compared to its typical horizontal extent, we are able to solve for the velocity components and pressure analytically. Using these results, a differential equation for the free surface Shape is obtained, which must in general be solved numerically. Motivated by the aim of understanding flows in static spiral particle separators used in mineral processing, we i...
J. E. F. Green - One of the best experts on this subject based on the ideXlab platform.
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particle laden thin film flow in helical channels with arbitrary shallow cross Sectional Shape
Physics of Fluids, 2019Co-Authors: David Arnold, Yvonne M. Stokes, J. E. F. GreenAbstract:Particle-laden flows in helical channels are of interest for their applications in spiral particle separators used in the mining and mineral processing industries. In this paper, we extend the previous work of Lee, Stokes, and Bertozzi [“Behaviour of a particle-laden flow in a spiral channel,” Phys. Fluids 26, 043302 (2014)] by studying thin-film flows of monodisperse particle-laden fluid in helically wound channels of arbitrary centerline curvature and torsion and arbitrary cross-Sectional Shape. In the case where the particles are uniformly distributed through the depth of the film, significant analytic progress can be made yielding insight into the influence of channel geometry on particle distribution across the channel cross section: the governing equations reduce to a single nonlinear ordinary differential equation, which is readily integrated numerically to obtain the solution subject to appropriate boundary conditions. Motivated by possible application to the design of spiral separators, we consider the effects of changing the channel centerline geometry, the cross-Sectional Shape and the particle density on the resulting flows, and the radial distribution of particles. Our results support the findings in the work of Arnold, Stokes, and Green [“Thin-film flow in helically wound rectangular channels of arbitrary torsion and curvature,” J. Fluid Mech. 764, 76–94 (2015)] regarding the effect of channel centerline geometry and cross-Sectional Shape on flows in particle-free regions. In particle-rich regions, similar effects are seen although the primary velocity is lower due to increased effective mixture viscosity. Of key interest is the effect of channel geometry on the focusing of the particles for given fluxes of fluid and particles. We find that introducing a trench into the channel cross section, a feature often used in commercial spiral particle separators, leads to a smaller radial width of the particle-rich region, i.e., sharper focusing of the particles, which is consistent with experiments showing that channel geometry influences particle separation in a spiral separator.Particle-laden flows in helical channels are of interest for their applications in spiral particle separators used in the mining and mineral processing industries. In this paper, we extend the previous work of Lee, Stokes, and Bertozzi [“Behaviour of a particle-laden flow in a spiral channel,” Phys. Fluids 26, 043302 (2014)] by studying thin-film flows of monodisperse particle-laden fluid in helically wound channels of arbitrary centerline curvature and torsion and arbitrary cross-Sectional Shape. In the case where the particles are uniformly distributed through the depth of the film, significant analytic progress can be made yielding insight into the influence of channel geometry on particle distribution across the channel cross section: the governing equations reduce to a single nonlinear ordinary differential equation, which is readily integrated numerically to obtain the solution subject to appropriate boundary conditions. Motivated by possible application to the design of spiral separators, we consid...
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Particle-laden thin-film flow in helical channels with arbitrary shallow cross-Sectional Shape
arXiv: Fluid Dynamics, 2019Co-Authors: David Arnold, Yvonne M. Stokes, J. E. F. GreenAbstract:Particle-laden flows in helical channels are of interest for their applications in spiral particle separators used in the mining and mineral processing industries. In this paper, we extend the previous work of Lee, Stokes, Bertozzi (2013) by studying thin-film flows of mono-disperse particle-laden fluid in helically-wound channels of arbitrary centreline curvature and torsion, and arbitrary cross-Sectional Shape. In the case where the particles are uniformly distributed through the depth of the film, significant analytic progress can be made: the governing equations reduce to a single nonlinear ordinary differential equation, which is readily integrated numerically to obtain the solution subject to appropriate boundary conditions. Motivated by possible application to the design of spiral separators, we consider the effects of changing the channel centreline geometry, the cross-Sectional Shape and the particle density on the resulting flows and the radial distribution of particles. Our results support the findings in Arnold, Stokes, Green (2016) regarding the effect of channel centreline geometry and cross-Sectional Shape on flows in particle-free regions. In particle-rich regions, similar effects are seen, although the primary velocity is lower due to increased effective mixture viscosity. \ys{Of key interest, is the effect of channel geometry on the focusing of the particles, for given fluxes of fluid and particles. We find that introducing a trench into the channel cross-section, a feature often used in commercial spiral particle separators, leads to smaller radial width of the particle-rich region, i.e. sharper focusing of the particles, which is consistent with experiments showing that channel geometry influences particle separation in a spiral separator.
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thin film flow in helically wound shallow channels of arbitrary cross Sectional Shape
Physics of Fluids, 2017Co-Authors: David Arnold, Y M Stokes, J. E. F. GreenAbstract:We consider the steady, gravity-driven flow of a thin film of viscous fluid down a helically wound shallow channel of arbitrary cross-Sectional Shape with arbitrary torsion and curvature. This extends our previous work [D. J. Arnold et al., “Thin-film flow in helically-wound rectangular channels of arbitrary torsion and curvature,” J. Fluid Mech. 764, 76–94 (2015)] on channels of rectangular cross section. The Navier-Stokes equations are expressed in a novel, non-orthogonal coordinate system fitted to the channel bottom. By assuming that the channel depth is small compared to its width and that the fluid depth in the vertical direction is also small compared to its typical horizontal extent, we are able to solve for the velocity components and pressure analytically. Using these results, a differential equation for the free surface Shape is obtained, which must in general be solved numerically. Motivated by the aim of understanding flows in static spiral particle separators used in mineral processing, we i...
Seiichi Ibaraki - One of the best experts on this subject based on the ideXlab platform.
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An investigation of volute cross-Sectional Shape on turbocharger turbine under pulsating conditions in internal combustion engine
Energy Conversion and Management, 2015Co-Authors: Mingyang Yang, Srithar Rajoo, Ricardo F. Martinez-botas, Takao Yokoyama, Seiichi IbarakiAbstract:Engine downsizing is a proven method for CO2 reduction in Internal Combustion Engine (ICE). A turbocharger, which reclaims the energy from the exhaust gas to boost the intake air, can effectively improve the power density of the engine thus is one of the key enablers to achieve the engine downsizing. Acknowledging its importance, many research efforts have gone into improving a turbocharger performance, which includes turbine volute. The cross-section design of a turbine volute in a turbocharger is usually a compromise between the engine level packaging and desired performance. Thus, it is beneficial to evaluate the effects of cross-Sectional Shape on a turbine performance. This paper presents experimental and computational investigation of the influence of volute cross-Sectional Shape on the performance of a radial turbocharger turbine under pulsating conditions. The cross-Sectional Shape of the baseline volute (denoted as Volute B) was optimized (Volute A) while the annulus distribution of area-to-radius ratio (A/R) for the two volute configurations are kept the same. Experimental results show that the turbine with the optimized volute A has better cycle averaged efficiency under pulsating flow conditions, for different loadings and frequencies. The advantage of performance is influenced by the operational conditions. After the experiment, a validated unsteady computational fluid dynamics (CFD) modeling was employed to investigate the mechanism by which performance differs between the baseline volute and the optimized version. Computational results show a stronger flow distortion in spanwise direction at the rotor inlet with the baseline volute. Furthermore, compared with the optimized volute, the flow distortion is more sensitive to the pulsating flow conditions in the baseline volute. This is due to the different secondary flow pattern in the cross-sections, hence demonstrating a direction for desired volute cross-Sectional Shape to be used in a turbocharger radial turbine for internal combustion engine.
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influence of volute cross Sectional Shape of a nozzleless turbocharger turbine under pulsating flow conditions
ASME Turbo Expo 2014: Turbine Technical Conference and Exposition GT 2014, 2014Co-Authors: Mingyang Yang, Srithar Rajoo, Takao Yokoyama, Ricardo Martinezbotas, Seiichi IbarakiAbstract:This paper presents an experimental and computational investigation of the influence of volute cross-Sectional Shape on the performance of a radial turbocharger turbine under pulsating conditions. Two volute configurations (denoted volute A and B) with the same area-to-radius ratio (A/R) distribution but different aspect ratios are rapid prototyped and tested with a same radial rotor. Experimental results show that the turbine with smaller aspect ratio volute (volute A), which has a squarish Shape, shows consistently better cycle averaged efficiency at different loadings and frequencies, and the magnitude of improvement is influenced by the operational conditions. In consequent to experiments, a reduced order unsteady computational fluid dynamics (CFD) method was employed to investigate the mechanism of the performance discrepancies between volute A and B. Computational results show a stronger flow angle distortion in both circumferential and spanwise direction for volute B. Furthermore, compared with the volute A, the flow distortion near the shroud at the rotor inlet is evidently amplified by the volute B under pulsating conditions compared with the corresponding steady condition. Results in this paper, in general, demonstrate a direction for desired volute cross-Sectional Shape to be used in a turbocharger radial turbine.© 2014 ASME
Mingyang Yang - One of the best experts on this subject based on the ideXlab platform.
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An investigation of volute cross-Sectional Shape on turbocharger turbine under pulsating conditions in internal combustion engine
Energy Conversion and Management, 2015Co-Authors: Mingyang Yang, Srithar Rajoo, Ricardo F. Martinez-botas, Takao Yokoyama, Seiichi IbarakiAbstract:Engine downsizing is a proven method for CO2 reduction in Internal Combustion Engine (ICE). A turbocharger, which reclaims the energy from the exhaust gas to boost the intake air, can effectively improve the power density of the engine thus is one of the key enablers to achieve the engine downsizing. Acknowledging its importance, many research efforts have gone into improving a turbocharger performance, which includes turbine volute. The cross-section design of a turbine volute in a turbocharger is usually a compromise between the engine level packaging and desired performance. Thus, it is beneficial to evaluate the effects of cross-Sectional Shape on a turbine performance. This paper presents experimental and computational investigation of the influence of volute cross-Sectional Shape on the performance of a radial turbocharger turbine under pulsating conditions. The cross-Sectional Shape of the baseline volute (denoted as Volute B) was optimized (Volute A) while the annulus distribution of area-to-radius ratio (A/R) for the two volute configurations are kept the same. Experimental results show that the turbine with the optimized volute A has better cycle averaged efficiency under pulsating flow conditions, for different loadings and frequencies. The advantage of performance is influenced by the operational conditions. After the experiment, a validated unsteady computational fluid dynamics (CFD) modeling was employed to investigate the mechanism by which performance differs between the baseline volute and the optimized version. Computational results show a stronger flow distortion in spanwise direction at the rotor inlet with the baseline volute. Furthermore, compared with the optimized volute, the flow distortion is more sensitive to the pulsating flow conditions in the baseline volute. This is due to the different secondary flow pattern in the cross-sections, hence demonstrating a direction for desired volute cross-Sectional Shape to be used in a turbocharger radial turbine for internal combustion engine.
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influence of volute cross Sectional Shape of a nozzleless turbocharger turbine under pulsating flow conditions
ASME Turbo Expo 2014: Turbine Technical Conference and Exposition GT 2014, 2014Co-Authors: Mingyang Yang, Srithar Rajoo, Takao Yokoyama, Ricardo Martinezbotas, Seiichi IbarakiAbstract:This paper presents an experimental and computational investigation of the influence of volute cross-Sectional Shape on the performance of a radial turbocharger turbine under pulsating conditions. Two volute configurations (denoted volute A and B) with the same area-to-radius ratio (A/R) distribution but different aspect ratios are rapid prototyped and tested with a same radial rotor. Experimental results show that the turbine with smaller aspect ratio volute (volute A), which has a squarish Shape, shows consistently better cycle averaged efficiency at different loadings and frequencies, and the magnitude of improvement is influenced by the operational conditions. In consequent to experiments, a reduced order unsteady computational fluid dynamics (CFD) method was employed to investigate the mechanism of the performance discrepancies between volute A and B. Computational results show a stronger flow angle distortion in both circumferential and spanwise direction for volute B. Furthermore, compared with the volute A, the flow distortion near the shroud at the rotor inlet is evidently amplified by the volute B under pulsating conditions compared with the corresponding steady condition. Results in this paper, in general, demonstrate a direction for desired volute cross-Sectional Shape to be used in a turbocharger radial turbine.© 2014 ASME
Wenjie Zuo - One of the best experts on this subject based on the ideXlab platform.
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cross Sectional Shape design of automobile structure considering rigidity and driver s field of view
Advances in Engineering Software, 2018Co-Authors: Wenjie Zuo, Xing Zhao, Jiantao BaiAbstract:Abstract Thin-walled beam structure can be used to efficiently predict the performances of automobile frame for conceptual design. However, it is an open issue to acquire an accurate cross-Sectional Shape of A-pillar structure considering both rigidity and driver's field of view (DFOV). This paper proposes an approach to calculate the cross-Sectional rigidity and DFOV. Firstly, formulations of cross-Sectional properties, including open, single-cell, double-cell, three-cell, four-cell section, are summarized. Secondly, the obstruction angle is introduced to describe DFOV, which is acquired by a nonlinear optimization model. Finally, a A-pillar example of Toyota RAV4, solved by the developed software – CarFrame, proves that the proposed method can be completely applied at the conceptual design of the automobile structure.
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Cross-Sectional Shape design and optimization of automotive body with stamping constraints
International Journal of Automotive Technology, 2016Co-Authors: Wenjie Zuo, Jiantao BaiAbstract:At conceptual design stage, automotive body is usually simplified as a frame structure, which consists of thinwalled beams (TWBs). Therefore, the most important issue is to determine the cross-Sectional Shape of TWBs under the requirement of mechanical properties. However, design engineers mostly depend on their experience or repeated modification to design the cross-Sectional Shape of TWBs. So this paper presents a rapidly cross-Sectional Shape design and optimization method to satisfy the demand of mechanical properties and meanwhile minimize the weight of TWB. Firstly, cross-Sectional mechanics property formulations are summarized. Especially, the torsional rigidity formulation of three-cell cross section is derived for the first time in this paper. Secondly, the Shape optimization model is created to minimize the weight of TWB and improve the mechanical properties, which is solved by genetic algorithm. Moreover, three stamping constraints, draft angle, chamfer radius and assembly, are introduced to promote the cross-Sectional Shape more practice. Lastly, numerical examples verify the effectiveness of the optimization model and show the application in structural modification of automotive frame.
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bi level optimization for the cross Sectional Shape of a thin walled car body frame with static stiffness and dynamic frequency stiffness constraints
Proceedings of the Institution of Mechanical Engineers Part D: Journal of Automobile Engineering, 2015Co-Authors: Wenjie ZuoAbstract:In usual automobile practice, the structural optimization of a car body is based on changes in the topology, the Shape, the cross-Sectional Shape and finally the thickness size successively depending on the development stages. However, design engineers mostly rely on their experience, intuition and data accumulation when making decisions on the cross-Sectional Shape of a car body frame. Therefore, a bi-level structural optimization model is proposed to determine the optimal cross-Sectional Shapes of each thin-walled beam and to achieve a lightweight car body frame with a high stiffness. Intermediate box sections are introduced to bridge the relationships between the two levels. At level 1, the car body frame with static stiffness and dynamic frequency stiffness constraints is optimized to obtain the optimal sizes of the box section, using a sequential approximate optimization method. At level 2, arbitrarily Shaped cross-sections constrained with cross-Sectional properties are optimized using a genetic algorithm. Component sensitivity analysis and manufacturing constraints promote this model to be closer to actual automobile practice. Finally, a numerical example, solved by the developed software Vehicle Body – Forward Design and Optimization, verifies that the presented method is effective in guiding the conceptual design of the car body frame.
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An object-oriented graphics interface design and optimization software for cross-Sectional Shape of automobile body
Advances in Engineering Software, 2013Co-Authors: Wenjie ZuoAbstract:At the conceptual design stage, automobile body is evaluated by simplified frame structure, consisting of thin-walled beams (TWBs). In the automobile practice, design engineers mostly rely on their experience and intuition when making decisions on cross-Sectional Shape of TWBs. So this paper presents a cross-Sectional Shape optimization method in order to achieve a high stiffness and lightweight TWB. Firstly, cross-Sectional property formulations is summarized and reviewed. Secondly, we build up a Shape optimization model to minimize the cross-Sectional area and satisfy the stiffness and manufacturing demands. The objective and constraints are nonlinear polynomial functions of the point coordinates defining the cross-Sectional Shape. Genetic algorithm is introduced to solve this nonlinear optimization problem. Thirdly, object-oriented programming and design patterns are adopted to design and implement the software framework. Lastly, numerical example is used to verify the presented method. This software, ''SuperBeam'' for short, is released for free and does speed up the conceptual design of automobile body.
