The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Sankaran Sundaresan - One of the best experts on this subject based on the ideXlab platform.
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validation of filtered two fluid models for gas particle flows against experimental data from bubbling fluidized bed
Powder Technology, 2015Co-Authors: Shailesh S Ozarkar, Fernando Eduardo Milioli, Christian C Milioli, Shuyan Wang, Sankaran SundaresanAbstract:Abstract Predictions of simulations based on filtered Two-Fluid Models (TFMs) with constitutive relations for filtered fluid–particle drag coefficient and filtered stresses proposed by Igci and Sundaresan [Ind. Eng. Chem. Res. 50 (2011) 13190–13201] and Milioli et al. [AIChE J. 59 (2013) 3265–3275] were compared against experimental data from a bubbling fluidized bed challenge problem put forward by the National Energy Technology Laboratory and Particulate Solids Research Inc. It is found that the most important correction to filtered models is a modification to the drag, and filtered stresses play a secondary role at best. As expected, coarse grid simulations using the kinetic-theory based TFM over-predicted the gas–particle drag force, yielding unphysical bed expansion. The filtered fluid–particle drag model proposed by Igci and Sundaresan that classifies the inhomogeneity in sub-filter scale flow structures using filter size and filtered particle volume fraction as markers also predicted unphysical bed expansion. Refined filtered drag models proposed by Milioli et al. based on filtered fluid–particle slip velocity as an additional marker led to good agreement with experimental data on bed expansion and the time-averaged gas pressure gradient. It was also observed that inadequate grid resolution in the region between gas distributor and the adjacent cylindrical wall of the test unit could lead to spurious asymmetric gas–particle flow predictions. With the inclusion of adequate inflation layer elements in that region, flow predictions became nearly symmetric with little to no effect on bed expansion predictions. However, it dramatically and qualitatively altered the details of gas–particle structures in the bed.
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Validation of filtered two-fluid models for gas–particle flows against experimental data from bubbling fluidized bed
Powder Technology, 2015Co-Authors: Shailesh S Ozarkar, Christian C Milioli, Fernando Eduardo Milioli, Shuyan Wang, Xiaokang Yan, Sankaran SundaresanAbstract:Abstract Predictions of simulations based on filtered Two-Fluid Models (TFMs) with constitutive relations for filtered fluid–particle drag coefficient and filtered stresses proposed by Igci and Sundaresan [Ind. Eng. Chem. Res. 50 (2011) 13190–13201] and Milioli et al. [AIChE J. 59 (2013) 3265–3275] were compared against experimental data from a bubbling fluidized bed challenge problem put forward by the National Energy Technology Laboratory and Particulate Solids Research Inc. It is found that the most important correction to filtered models is a modification to the drag, and filtered stresses play a secondary role at best. As expected, coarse grid simulations using the kinetic-theory based TFM over-predicted the gas–particle drag force, yielding unphysical bed expansion. The filtered fluid–particle drag model proposed by Igci and Sundaresan that classifies the inhomogeneity in sub-filter scale flow structures using filter size and filtered particle volume fraction as markers also predicted unphysical bed expansion. Refined filtered drag models proposed by Milioli et al. based on filtered fluid–particle slip velocity as an additional marker led to good agreement with experimental data on bed expansion and the time-averaged gas pressure gradient. It was also observed that inadequate grid resolution in the region between gas distributor and the adjacent cylindrical wall of the test unit could lead to spurious asymmetric gas–particle flow predictions. With the inclusion of adequate inflation layer elements in that region, flow predictions became nearly symmetric with little to no effect on bed expansion predictions. However, it dramatically and qualitatively altered the details of gas–particle structures in the bed.
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fluid particle drag in inertial polydisperse gas solid suspensions
Aiche Journal, 2009Co-Authors: William Holloway, Xiaolong Yin, Sankaran SundaresanAbstract:In this article, we extend the low Reynolds number fluid-particle drag relation proposed by Yin and Sundaresan for polydisperse systems to include the effect of moderate fluid inertia. The proposed model captures the fluid-particle drag results obtained from lattice-Boltzmann simulations of bidisperse and ternary suspensions at particle mixture Reynolds numbers ranging from 0 � Remix � 40, over a particle volume fraction range of 0.2 � f � 0.4, volume fraction ratios of 1 � fi/fj � 3, and particle diameter ratios of 1 � di/dj � 2.5. V C 2009 American Institute of Chemical Engineers AIChE J, 56: 1995–2004, 2010
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Fluid‐particle drag in inertial polydisperse gas–solid suspensions
Aiche Journal, 2009Co-Authors: William Holloway, Xiaolong Yin, Sankaran SundaresanAbstract:In this article, we extend the low Reynolds number fluid-particle drag relation proposed by Yin and Sundaresan for polydisperse systems to include the effect of moderate fluid inertia. The proposed model captures the fluid-particle drag results obtained from lattice-Boltzmann simulations of bidisperse and ternary suspensions at particle mixture Reynolds numbers ranging from 0 � Remix � 40, over a particle volume fraction range of 0.2 � f � 0.4, volume fraction ratios of 1 � fi/fj � 3, and particle diameter ratios of 1 � di/dj � 2.5. V C 2009 American Institute of Chemical Engineers AIChE J, 56: 1995–2004, 2010
Sundaresan Rajesh - One of the best experts on this subject based on the ideXlab platform.
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A Polymatroid Approach to Separable Convex Optimization with Linear Ascending Constraints
IEEE, 2014Co-Authors: P T Akhil, Singh Rahul, Sundaresan RajeshAbstract:We revisit a problem studied by Padakandla and Sundaresan SIAM J. Optim., August 2009] on the minimization of a separable convex function subject to linear ascending constraints. The problem arises as the core optimization in several resource allocation problems in wireless communication settings. It is also a special case of an optimization of a separable convex function over the bases of a specially structured polymatroid. We give an alternative proof of the correctness of the algorithm of Padakandla and Sundaresan. In the process we relax some of their restrictions placed on the objective function
William Holloway - One of the best experts on this subject based on the ideXlab platform.
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fluid particle drag in inertial polydisperse gas solid suspensions
Aiche Journal, 2009Co-Authors: William Holloway, Xiaolong Yin, Sankaran SundaresanAbstract:In this article, we extend the low Reynolds number fluid-particle drag relation proposed by Yin and Sundaresan for polydisperse systems to include the effect of moderate fluid inertia. The proposed model captures the fluid-particle drag results obtained from lattice-Boltzmann simulations of bidisperse and ternary suspensions at particle mixture Reynolds numbers ranging from 0 � Remix � 40, over a particle volume fraction range of 0.2 � f � 0.4, volume fraction ratios of 1 � fi/fj � 3, and particle diameter ratios of 1 � di/dj � 2.5. V C 2009 American Institute of Chemical Engineers AIChE J, 56: 1995–2004, 2010
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Fluid‐particle drag in inertial polydisperse gas–solid suspensions
Aiche Journal, 2009Co-Authors: William Holloway, Xiaolong Yin, Sankaran SundaresanAbstract:In this article, we extend the low Reynolds number fluid-particle drag relation proposed by Yin and Sundaresan for polydisperse systems to include the effect of moderate fluid inertia. The proposed model captures the fluid-particle drag results obtained from lattice-Boltzmann simulations of bidisperse and ternary suspensions at particle mixture Reynolds numbers ranging from 0 � Remix � 40, over a particle volume fraction range of 0.2 � f � 0.4, volume fraction ratios of 1 � fi/fj � 3, and particle diameter ratios of 1 � di/dj � 2.5. V C 2009 American Institute of Chemical Engineers AIChE J, 56: 1995–2004, 2010
P T Akhil - One of the best experts on this subject based on the ideXlab platform.
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NCC - A polymatroid approach to separable convex optimization with linear ascending constraints
2014 Twentieth National Conference on Communications (NCC), 2014Co-Authors: P T Akhil, Rahul Singh, Rajesh SundaresanAbstract:We revisit a problem studied by Padakandla and Sundaresan [SIAM J. Optim., August 2009] on the minimization of a separable convex function subject to linear ascending constraints. The problem arises as the core optimization in several resource allocation problems in wireless communication settings. It is also a special case of an optimization of a separable convex function over the bases of a specially structured polymatroid. We give an alternative proof of the correctness of the algorithm of Padakandla and Sundaresan. In the process we relax some of their restrictions placed on the objective function.
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A Polymatroid Approach to Separable Convex Optimization with Linear Ascending Constraints
IEEE, 2014Co-Authors: P T Akhil, Singh Rahul, Sundaresan RajeshAbstract:We revisit a problem studied by Padakandla and Sundaresan SIAM J. Optim., August 2009] on the minimization of a separable convex function subject to linear ascending constraints. The problem arises as the core optimization in several resource allocation problems in wireless communication settings. It is also a special case of an optimization of a separable convex function over the bases of a specially structured polymatroid. We give an alternative proof of the correctness of the algorithm of Padakandla and Sundaresan. In the process we relax some of their restrictions placed on the objective function
Xiaolong Yin - One of the best experts on this subject based on the ideXlab platform.
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fluid particle drag in inertial polydisperse gas solid suspensions
Aiche Journal, 2009Co-Authors: William Holloway, Xiaolong Yin, Sankaran SundaresanAbstract:In this article, we extend the low Reynolds number fluid-particle drag relation proposed by Yin and Sundaresan for polydisperse systems to include the effect of moderate fluid inertia. The proposed model captures the fluid-particle drag results obtained from lattice-Boltzmann simulations of bidisperse and ternary suspensions at particle mixture Reynolds numbers ranging from 0 � Remix � 40, over a particle volume fraction range of 0.2 � f � 0.4, volume fraction ratios of 1 � fi/fj � 3, and particle diameter ratios of 1 � di/dj � 2.5. V C 2009 American Institute of Chemical Engineers AIChE J, 56: 1995–2004, 2010
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Fluid‐particle drag in inertial polydisperse gas–solid suspensions
Aiche Journal, 2009Co-Authors: William Holloway, Xiaolong Yin, Sankaran SundaresanAbstract:In this article, we extend the low Reynolds number fluid-particle drag relation proposed by Yin and Sundaresan for polydisperse systems to include the effect of moderate fluid inertia. The proposed model captures the fluid-particle drag results obtained from lattice-Boltzmann simulations of bidisperse and ternary suspensions at particle mixture Reynolds numbers ranging from 0 � Remix � 40, over a particle volume fraction range of 0.2 � f � 0.4, volume fraction ratios of 1 � fi/fj � 3, and particle diameter ratios of 1 � di/dj � 2.5. V C 2009 American Institute of Chemical Engineers AIChE J, 56: 1995–2004, 2010
