The Experts below are selected from a list of 21 Experts worldwide ranked by ideXlab platform
Siamak Kazemzadeh Hannani - One of the best experts on this subject based on the ideXlab platform.
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a fully explicit three step sph algorithm for simulation of non newtonian fluid flow
International Journal of Numerical Methods for Heat & Fluid Flow, 2007Co-Authors: S M Hosseini, M T Manzari, Siamak Kazemzadeh HannaniAbstract:Purpose – This paper sets out to present a fully explicit smoothed particle hydrodynamics (SPH) method to solve non‐Newtonian fluid flow problems.Design/methodology/approach – The governing equations are momentum equations along with the continuity equation which are described in a Lagrangian framework. A new treatment similar to that used in Eulerian formulations is applied to viscous terms, which facilitates the implementation of various inelastic non‐Newtonian models. This approach utilizes the exact forms of the shear strain rate tensor and its second Principal Invariant to calculate the shear stress tensor. Three constitutive laws including power‐law, Bingham‐plastic and Herschel‐Bulkley models are studied in this work. The imposition of the incompressibility is fulfilled using a penalty‐like formulation which creates a trade‐off between the pressure and density variations. Solid walls are simulated by the boundary particles whose positions are fixed but contribute to the field variables in the same ...
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a fully explicit three step sph algorithm for simulation of non newtonian fluid flow
International Journal of Numerical Methods for Heat & Fluid Flow, 2007Co-Authors: S M Hosseini, M T Manzari, Siamak Kazemzadeh HannaniAbstract:Purpose – This paper sets out to present a fully explicit smoothed particle hydrodynamics (SPH) method to solve non‐Newtonian fluid flow problems.Design/methodology/approach – The governing equations are momentum equations along with the continuity equation which are described in a Lagrangian framework. A new treatment similar to that used in Eulerian formulations is applied to viscous terms, which facilitates the implementation of various inelastic non‐Newtonian models. This approach utilizes the exact forms of the shear strain rate tensor and its second Principal Invariant to calculate the shear stress tensor. Three constitutive laws including power‐law, Bingham‐plastic and Herschel‐Bulkley models are studied in this work. The imposition of the incompressibility is fulfilled using a penalty‐like formulation which creates a trade‐off between the pressure and density variations. Solid walls are simulated by the boundary particles whose positions are fixed but contribute to the field variables in the same ...
Xiaochun Fang - One of the best experts on this subject based on the ideXlab platform.
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on Principal Invariant subspaces
Acta Mathematica Sinica, 2015Co-Authors: Xiaochun FangAbstract:Let F and G be closed subspaces of the complex Hilbert space H, and U and V be closed subspaces of F and G, respectively. In this paper, using the technique of operator block, we present the necessary and sufficient conditions under which (U, V) is a pair of (strictly, non-degenerate) Principal Invariant subspaces for (F, G).
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Principal Invariant subspaces theorems
Linear and Multilinear Algebra, 2013Co-Authors: Xiaochun Fang, Fugen GaoAbstract:In this paper, we present the necessary and sufficient conditions for which the given pair of closed subspaces has a pair of non-trivial Principal Invariant subspaces. Using this we show that every pair of closed subspaces with or has a pair of non-trivial Principal Invariant subspaces. Also we prove that the pair of closed subspaces with has a pair of non-trivial Principal Invariant subspaces if and only if Similar results are proved for non-degenerate Principal Invariant subspaces.
S M Hosseini - One of the best experts on this subject based on the ideXlab platform.
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a fully explicit three step sph algorithm for simulation of non newtonian fluid flow
International Journal of Numerical Methods for Heat & Fluid Flow, 2007Co-Authors: S M Hosseini, M T Manzari, Siamak Kazemzadeh HannaniAbstract:Purpose – This paper sets out to present a fully explicit smoothed particle hydrodynamics (SPH) method to solve non‐Newtonian fluid flow problems.Design/methodology/approach – The governing equations are momentum equations along with the continuity equation which are described in a Lagrangian framework. A new treatment similar to that used in Eulerian formulations is applied to viscous terms, which facilitates the implementation of various inelastic non‐Newtonian models. This approach utilizes the exact forms of the shear strain rate tensor and its second Principal Invariant to calculate the shear stress tensor. Three constitutive laws including power‐law, Bingham‐plastic and Herschel‐Bulkley models are studied in this work. The imposition of the incompressibility is fulfilled using a penalty‐like formulation which creates a trade‐off between the pressure and density variations. Solid walls are simulated by the boundary particles whose positions are fixed but contribute to the field variables in the same ...
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a fully explicit three step sph algorithm for simulation of non newtonian fluid flow
International Journal of Numerical Methods for Heat & Fluid Flow, 2007Co-Authors: S M Hosseini, M T Manzari, Siamak Kazemzadeh HannaniAbstract:Purpose – This paper sets out to present a fully explicit smoothed particle hydrodynamics (SPH) method to solve non‐Newtonian fluid flow problems.Design/methodology/approach – The governing equations are momentum equations along with the continuity equation which are described in a Lagrangian framework. A new treatment similar to that used in Eulerian formulations is applied to viscous terms, which facilitates the implementation of various inelastic non‐Newtonian models. This approach utilizes the exact forms of the shear strain rate tensor and its second Principal Invariant to calculate the shear stress tensor. Three constitutive laws including power‐law, Bingham‐plastic and Herschel‐Bulkley models are studied in this work. The imposition of the incompressibility is fulfilled using a penalty‐like formulation which creates a trade‐off between the pressure and density variations. Solid walls are simulated by the boundary particles whose positions are fixed but contribute to the field variables in the same ...
Leslie Morland - One of the best experts on this subject based on the ideXlab platform.
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the influence of third shear stress Invariant dependence in the isotropic viscous relation on the reduced model for ice sheet flow
Journal of Glaciology, 2007Co-Authors: Leslie MorlandAbstract:Ice-sheet flow solutions commonly adopt a simple isotropic viscous law, in which the deviatoric stress is coaxial with the strain rate, and the single response function depends on only one Invariant, the second Principal Invariant of the deviatoric stress. This can be correlated with single-stress component tests, which cannot, however, verify the validity of the simplification. Morland (2007) has shown how combined compression and shear tests can verify and correlate a general quadratic isotropic viscous relation, or simply third Invariant dependence, and there is evidence that at least third Principal Invariant dependence is required. Morland (2007) showed that a significant quadratic term changes the relative stress magnitudes in the reduced model for ice-sheet flow, that crucial simplifications are not achieved and formally noted that dependence on the third Invariant in the coaxial relation also prevented the simplification. It is now shown that, provided the third Invariant dependence does not dominate the isotropic relation, further asymptotic expansion does yield the reduced model simplification, and the influence of different weightings of third Invariant dependence is illustrated by a comparison of steady radial flow solutions over a flat bed. It is found that the third Invariant dependence does not have a large influence in these examples.
M T Manzari - One of the best experts on this subject based on the ideXlab platform.
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a fully explicit three step sph algorithm for simulation of non newtonian fluid flow
International Journal of Numerical Methods for Heat & Fluid Flow, 2007Co-Authors: S M Hosseini, M T Manzari, Siamak Kazemzadeh HannaniAbstract:Purpose – This paper sets out to present a fully explicit smoothed particle hydrodynamics (SPH) method to solve non‐Newtonian fluid flow problems.Design/methodology/approach – The governing equations are momentum equations along with the continuity equation which are described in a Lagrangian framework. A new treatment similar to that used in Eulerian formulations is applied to viscous terms, which facilitates the implementation of various inelastic non‐Newtonian models. This approach utilizes the exact forms of the shear strain rate tensor and its second Principal Invariant to calculate the shear stress tensor. Three constitutive laws including power‐law, Bingham‐plastic and Herschel‐Bulkley models are studied in this work. The imposition of the incompressibility is fulfilled using a penalty‐like formulation which creates a trade‐off between the pressure and density variations. Solid walls are simulated by the boundary particles whose positions are fixed but contribute to the field variables in the same ...
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a fully explicit three step sph algorithm for simulation of non newtonian fluid flow
International Journal of Numerical Methods for Heat & Fluid Flow, 2007Co-Authors: S M Hosseini, M T Manzari, Siamak Kazemzadeh HannaniAbstract:Purpose – This paper sets out to present a fully explicit smoothed particle hydrodynamics (SPH) method to solve non‐Newtonian fluid flow problems.Design/methodology/approach – The governing equations are momentum equations along with the continuity equation which are described in a Lagrangian framework. A new treatment similar to that used in Eulerian formulations is applied to viscous terms, which facilitates the implementation of various inelastic non‐Newtonian models. This approach utilizes the exact forms of the shear strain rate tensor and its second Principal Invariant to calculate the shear stress tensor. Three constitutive laws including power‐law, Bingham‐plastic and Herschel‐Bulkley models are studied in this work. The imposition of the incompressibility is fulfilled using a penalty‐like formulation which creates a trade‐off between the pressure and density variations. Solid walls are simulated by the boundary particles whose positions are fixed but contribute to the field variables in the same ...