The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Eugenio Oñate - One of the best experts on this subject based on the ideXlab platform.
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updated lagrangian mixed finite element formulation for quasi and fully Incompressible Fluids
Computational Mechanics, 2014Co-Authors: Eugenio Oñate, Josep Maria CarbonellAbstract:We present a mixed velocity---pressure finite element formulation for solving the updated Lagrangian equations for quasi and fully Incompressible Fluids. Details of the governing equations for the conservation of momentum and mass are given in both differential and variational form. The finite element interpolation uses an equal order approximation for the velocity and pressure unknowns. The procedure for obtaining stabilized FEM solutions is outlined. The solution in time of the discretized governing conservation equations using an incremental iterative segregated scheme is described. The linearization of these equations and the derivation of the corresponding tangent stiffness matrices is detailed. Other iterative schemes for the direct computation of the nodal velocities and pressures at the updated configuration are presented. The advantages and disadvantages of choosing the current or the updated configuration as the reference configuration in the Lagrangian formulation are discussed.
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lagrangian formulation for finite element analysis of quasi Incompressible Fluids with reduced mass losses
International Journal for Numerical Methods in Fluids, 2014Co-Authors: Eugenio Oñate, Alessandro Franci, Josep Maria CarbonellAbstract:SUMMARY We present a Lagrangian formulation for finite element analysis of quasi-Incompressible Fluids that has excellent mass preservation features. The success of the formulation lays on a new residual-based stabilized expression of the mass balance equation obtained using the finite calculus method. The governing equations are discretized with the FEM using simplicial elements with equal linear interpolation for the velocities and the pressure. The merits of the formulation in terms of reduced mass loss and overall accuracy are verified in the solution of 2D and 3D quasi-Incompressible free-surface flow problems using the particle FEM (www.cimne.com/pfem). Examples include the sloshing of water in a tank, the collapse of one and two water columns in rectangular and prismatic tanks, and the falling of a water sphere into a cylindrical tank containing water. Copyright © 2014 John Wiley & Sons, Ltd.
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unified lagrangian formulation for elastic solids and Incompressible Fluids application to fluid structure interaction problems via the pfem
Computer Methods in Applied Mechanics and Engineering, 2008Co-Authors: Sergio Idelsohn, Alejandro Cesar Limache, J Marti, Eugenio OñateAbstract:Abstract We present a general Lagrangian formulation for treating elastic solids and quasi/fully Incompressible Fluids in a unified form. The formulation allows to treat solid and fluid subdomains in a unified manner in fluid–structure interaction (FSI) situations. In our work the FSI problem is solved via the particle finite element method (PFEM). The PFEM is an effective technique for modeling complex interactions between floating and submerged bodies and free surface flows, accounting for splashing of waves, large motions of the bodies and frictional contact conditions. Applications of the unified Lagrangian formulation to a number of FSI problems are given.
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Unified Lagrangian formulation for elastic solids and Incompressible Fluids: Application to fluid–structure interaction problems via the PFEM
Computer Methods in Applied Mechanics and Engineering, 2008Co-Authors: Sergio Idelsohn, Alejandro Cesar Limache, J Marti, Eugenio OñateAbstract:Abstract We present a general Lagrangian formulation for treating elastic solids and quasi/fully Incompressible Fluids in a unified form. The formulation allows to treat solid and fluid subdomains in a unified manner in fluid–structure interaction (FSI) situations. In our work the FSI problem is solved via the particle finite element method (PFEM). The PFEM is an effective technique for modeling complex interactions between floating and submerged bodies and free surface flows, accounting for splashing of waves, large motions of the bodies and frictional contact conditions. Applications of the unified Lagrangian formulation to a number of FSI problems are given.
Thomas C Sideris - One of the best experts on this subject based on the ideXlab platform.
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affine motion of 2d Incompressible Fluids surrounded by vacuum and flows in sl 2 r
Communications in Mathematical Physics, 2020Co-Authors: Jay Roberts, Steve Shkoller, Thomas C SiderisAbstract:The affine motion of two-dimensional (2d) Incompressible Fluids surrounded by vacuum can be reduced to a completely integrable and globally solvable Hamiltonian system of ordinary differential equations for the deformation gradient in $$\mathrm{SL}(2,\mathbb {R})$$. In the case of perfect Fluids, the motion is given by geodesic flow in $$\mathrm{SL}(2,\mathbb {R})$$ with the Euclidean metric, while for magnetically conducting Fluids (MHD), the motion is governed by a harmonic oscillator in $$\mathrm{SL}(2,\mathbb {R})$$. A complete classification of the dynamics is given including rigid motions, rotating eddies with stable and unstable manifolds, and solutions with vanishing pressure. For perfect Fluids, the displacement generically becomes unbounded, as $$t\rightarrow \pm \infty $$. For MHD, solutions are bounded and generically quasi-periodic and recurrent.
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Affine Motion of 2d Incompressible Fluids Surrounded by Vacuum and Flows in $$\mathrm{SL}(2,\mathbb {R})$$SL(2,R)
Communications in Mathematical Physics, 2020Co-Authors: Jay Roberts, Steve Shkoller, Thomas C SiderisAbstract:The affine motion of two-dimensional (2d) Incompressible Fluids surrounded by vacuum can be reduced to a completely integrable and globally solvable Hamiltonian system of ordinary differential equations for the deformation gradient in $$\mathrm{SL}(2,\mathbb {R})$$ SL ( 2 , R ) . In the case of perfect Fluids, the motion is given by geodesic flow in $$\mathrm{SL}(2,\mathbb {R})$$ SL ( 2 , R ) with the Euclidean metric, while for magnetically conducting Fluids (MHD), the motion is governed by a harmonic oscillator in $$\mathrm{SL}(2,\mathbb {R})$$ SL ( 2 , R ) . A complete classification of the dynamics is given including rigid motions, rotating eddies with stable and unstable manifolds, and solutions with vanishing pressure. For perfect Fluids, the displacement generically becomes unbounded, as $$t\rightarrow \pm \infty $$ t → ± ∞ . For MHD, solutions are bounded and generically quasi-periodic and recurrent.
Sergio Idelsohn - One of the best experts on this subject based on the ideXlab platform.
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unified lagrangian formulation for elastic solids and Incompressible Fluids application to fluid structure interaction problems via the pfem
Computer Methods in Applied Mechanics and Engineering, 2008Co-Authors: Sergio Idelsohn, Alejandro Cesar Limache, J Marti, Eugenio OñateAbstract:Abstract We present a general Lagrangian formulation for treating elastic solids and quasi/fully Incompressible Fluids in a unified form. The formulation allows to treat solid and fluid subdomains in a unified manner in fluid–structure interaction (FSI) situations. In our work the FSI problem is solved via the particle finite element method (PFEM). The PFEM is an effective technique for modeling complex interactions between floating and submerged bodies and free surface flows, accounting for splashing of waves, large motions of the bodies and frictional contact conditions. Applications of the unified Lagrangian formulation to a number of FSI problems are given.
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Unified Lagrangian formulation for elastic solids and Incompressible Fluids: Application to fluid–structure interaction problems via the PFEM
Computer Methods in Applied Mechanics and Engineering, 2008Co-Authors: Sergio Idelsohn, Alejandro Cesar Limache, J Marti, Eugenio OñateAbstract:Abstract We present a general Lagrangian formulation for treating elastic solids and quasi/fully Incompressible Fluids in a unified form. The formulation allows to treat solid and fluid subdomains in a unified manner in fluid–structure interaction (FSI) situations. In our work the FSI problem is solved via the particle finite element method (PFEM). The PFEM is an effective technique for modeling complex interactions between floating and submerged bodies and free surface flows, accounting for splashing of waves, large motions of the bodies and frictional contact conditions. Applications of the unified Lagrangian formulation to a number of FSI problems are given.
Song Zheng - One of the best experts on this subject based on the ideXlab platform.
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Phase-field-theory-based lattice Boltzmann equation method for N immiscible Incompressible Fluids.
Physical Review E, 2019Co-Authors: Lin Zheng, Song ZhengAbstract:From the phase field theory, we develop a lattice Boltzmann equation (LBE) method for $N$ ($N\ensuremath{\ge}2$) immiscible Incompressible Fluids, and the Cahn-Hilliard equation, which could capture the interfaces between different phases, is also solved by LBE for an $N$-phase system. In this model, the interface force of $N$ immiscible Incompressible Fluids is incorporated by chemical potential form, and the fluid-fluid surface tensions could be directly calculated and independently tuned. Numerical simulations including two stationary droplets, spreading of a liquid lens with and without gravity and two immiscible liquid lenses, and phase separation are conducted to validate the present LBE, and numerical results show that the predictions by LBE agree well with the analytical solutions and other numerical results.
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Phase-field-theory-based lattice Boltzmann equation method for N immiscible Incompressible Fluids.
Physical review. E, 2019Co-Authors: Lin Zheng, Song ZhengAbstract:From the phase field theory, we develop a lattice Boltzmann equation (LBE) method for N (N≥2) immiscible Incompressible Fluids, and the Cahn-Hilliard equation, which could capture the interfaces between different phases, is also solved by LBE for an N-phase system. In this model, the interface force of N immiscible Incompressible Fluids is incorporated by chemical potential form, and the fluid-fluid surface tensions could be directly calculated and independently tuned. Numerical simulations including two stationary droplets, spreading of a liquid lens with and without gravity and two immiscible liquid lenses, and phase separation are conducted to validate the present LBE, and numerical results show that the predictions by LBE agree well with the analytical solutions and other numerical results.
Jay Roberts - One of the best experts on this subject based on the ideXlab platform.
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affine motion of 2d Incompressible Fluids surrounded by vacuum and flows in sl 2 r
Communications in Mathematical Physics, 2020Co-Authors: Jay Roberts, Steve Shkoller, Thomas C SiderisAbstract:The affine motion of two-dimensional (2d) Incompressible Fluids surrounded by vacuum can be reduced to a completely integrable and globally solvable Hamiltonian system of ordinary differential equations for the deformation gradient in $$\mathrm{SL}(2,\mathbb {R})$$. In the case of perfect Fluids, the motion is given by geodesic flow in $$\mathrm{SL}(2,\mathbb {R})$$ with the Euclidean metric, while for magnetically conducting Fluids (MHD), the motion is governed by a harmonic oscillator in $$\mathrm{SL}(2,\mathbb {R})$$. A complete classification of the dynamics is given including rigid motions, rotating eddies with stable and unstable manifolds, and solutions with vanishing pressure. For perfect Fluids, the displacement generically becomes unbounded, as $$t\rightarrow \pm \infty $$. For MHD, solutions are bounded and generically quasi-periodic and recurrent.
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Affine Motion of 2d Incompressible Fluids Surrounded by Vacuum and Flows in $$\mathrm{SL}(2,\mathbb {R})$$SL(2,R)
Communications in Mathematical Physics, 2020Co-Authors: Jay Roberts, Steve Shkoller, Thomas C SiderisAbstract:The affine motion of two-dimensional (2d) Incompressible Fluids surrounded by vacuum can be reduced to a completely integrable and globally solvable Hamiltonian system of ordinary differential equations for the deformation gradient in $$\mathrm{SL}(2,\mathbb {R})$$ SL ( 2 , R ) . In the case of perfect Fluids, the motion is given by geodesic flow in $$\mathrm{SL}(2,\mathbb {R})$$ SL ( 2 , R ) with the Euclidean metric, while for magnetically conducting Fluids (MHD), the motion is governed by a harmonic oscillator in $$\mathrm{SL}(2,\mathbb {R})$$ SL ( 2 , R ) . A complete classification of the dynamics is given including rigid motions, rotating eddies with stable and unstable manifolds, and solutions with vanishing pressure. For perfect Fluids, the displacement generically becomes unbounded, as $$t\rightarrow \pm \infty $$ t → ± ∞ . For MHD, solutions are bounded and generically quasi-periodic and recurrent.
