Jaroslav Hron | Charles University, Prague (original) (raw)

Papers by Jaroslav Hron

Research paper thumbnail of Numerical solution of fluid-structure interaction with applications in biomechanics

The 41st Annual SES Technical Meeting, 2004

In bioengineering applications problems of flow interacting with elastic solid are very common. W... more In bioengineering applications problems of flow interacting with elastic solid are very common. We formulate the problem of interaction between an incompressible fluid and an incompressible elastic material in the arbitrary Lagrangian-Eulerian formulation, including the possibility ...

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Research paper thumbnail of Morphological and Hemodynamic Changes during Cerebral Aneurysm Growth

Brain Sciences

Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic propert... more Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic properties related to the rupture of cerebral aneurysms. Few of these studies deal specifically with aneurysm growth and most only use a single time instance within the aneurysm growth history. The present retrospective study investigated four patient-specific aneurysms, once at initial diagnosis and then at follow-up, to analyze hemodynamic and morphological changes. Aneurysm geometries were segmented via the medical image processing software Mimics. The geometries were meshed and a computational fluid dynamics (CFD) analysis was performed using ANSYS. Results showed that major geometry bulk growth occurred in areas of low wall shear stress (WSS). Wall shape remodeling near neck impingement regions occurred in areas with large gradients of WSS and oscillatory shear index. This study found that growth occurred in areas where low WSS was accompanied by high velocity gradients between the aneurys...

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Research paper thumbnail of Tidal dissipation in Enceladus’ uneven, fractured ice shell

Icarus

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Research paper thumbnail of Plume Activity and Tidal Deformation on Enceladus Influenced by Faults and Variable Ice Shell Thickness

Astrobiology

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Research paper thumbnail of Mathematical Description of Soft Tissue Mechanics

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Research paper thumbnail of Introduction: Numerical Benchmarking of Fluid-Structure Interaction

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Research paper thumbnail of Numerical analysis and a-posteriori error control for a new nonconforming linear finite element on quadrilaterals

Starting with a short introduction of the new nonconforming linear quadrilateral ˜ P1-finite elem... more Starting with a short introduction of the new nonconforming linear quadrilateral ˜ P1-finite element which has been recently proposed by Park ((13, 14)), we examine in detail the numerical behaviour of this element with special emphasis on the treatment of Dirichlet boundary conditions, efficient matrix assembly, solver aspects and the use as Stokes element in CFD. Furthermore, we compare the

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Research paper thumbnail of A Monolithic Fem Solver for an Ale Formulation of Fluid-Structure Interaction with Configuration for Numerical Benchmarking

We investigate a monolithic algorithm to solve the problem of time dependent interaction between ... more We investigate a monolithic algorithm to solve the problem of time dependent interaction between an incompressible viscous fluid and an elastic solid. The continuous formulation of the problem and its discretization is done in a monolithic way, treating the problem as one continuum. The Q2/P dis 1 finite elements are used for the discretization and an approximate Newton method with

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Research paper thumbnail of A monolithic FEM/Multigrid solver for ALE formulation of fluid structure interaction with application in biomechanics

We investigate a new method of solving the problem of fluid-structure interaction of an incompres... more We investigate a new method of solving the problem of fluid-structure interaction of an incompressible elastic object in laminar incompressible viscous flow. Our proposed method is based on a fully implicit, monolithic formulation of the problem in the arbitrary Lagrangian-Eulerian framework. High order FEM is used to obtain the discrete approximation of the problem. In order to solve the resulting

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Research paper thumbnail of Numerical analysis of a new time-stepping θ-scheme for incompressible flow simulations

In [13], we had performed numerical comparisons for different time stepping schemes for the incom... more In [13], we had performed numerical comparisons for different time stepping schemes for the incompressible Navier-Stokes equations. In this paper, we present the numerical analysis in the context of the Navier-Stokes equations for a new time-stepping θ-scheme which has been recently proposed by Glowinski [5]. Like the well-known classical Fractional-Step-θ-scheme which had been introduced by Glowinski [1], [4], too, and which is still one of the most popular time stepping schemes, with or without operator splitting techniques, this new scheme consists of 3 substeps with non-equidistant substepping to build one macro time step. However, in contrast to the Fractional-Step-θ-scheme, the second substep can be formulated as an extrapolation step for previously computed data only, and the two remaining substeps look like a Backward Euler step so that no expensive operator evaluations for the right hand side vector with older solutions, as for instance in the Crank-Nicolson scheme, have to...

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Research paper thumbnail of Numerical Simulation of Fluid Structure Interaction with Application to Aneurysm Hemodynamics

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Research paper thumbnail of The Computational Fluid Dynamics Rupture Challenge 2013-Phase I: Prediction of Rupture Status in Intracranial Aneurysms

AJNR. American journal of neuroradiology, Jan 11, 2014

Rupture risk assessment for intracranial aneurysms remains challenging, and risk factors, includi... more Rupture risk assessment for intracranial aneurysms remains challenging, and risk factors, including wall shear stress, are discussed controversially. The primary purpose of the presented challenge was to determine how consistently aneurysm rupture status and rupture site could be identified on the basis of computational fluid dynamics. Two geometrically similar MCA aneurysms were selected, 1 ruptured, 1 unruptured. Participating computational fluid dynamics groups were blinded as to which case was ruptured. Participants were provided with digitally segmented lumen geometries and, for this phase of the challenge, were free to choose their own flow rates, blood rheologies, and so forth. Participants were asked to report which case had ruptured and the likely site of rupture. In parallel, lumen geometries were provided to a group of neurosurgeons for their predictions of rupture status and site. Of 26 participating computational fluid dynamics groups, 21 (81%) correctly identified the ...

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Research paper thumbnail of Numerical Methods and Nature

Journal of Scientific Computing, 2006

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Research paper thumbnail of Numerical analysis for a new non-conforming linear finite element on quadrilaterals

Journal of Computational and Applied Mathematics, 2006

Starting with a short introduction of a new non-conforming linear quadrilateral View the MathML s... more Starting with a short introduction of a new non-conforming linear quadrilateral View the MathML source -finite element which has been recently proposed by Park [A study on locking phenomena in finite element methods, Ph.D. Thesis, Seoul National University, February 2002] and ...

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Research paper thumbnail of FEM multigrid techniques for fluid–structure interaction with application to hemodynamics

Applied Numerical Mathematics, 2012

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Research paper thumbnail of Numerical analysis and a-posteriori error control for a new nonconforming linear finite element on quadrilaterals

Starting with a short introduction of the new nonconforming linear quadrilateral ˜P1-finite eleme... more Starting with a short introduction of the new nonconforming linear quadrilateral ˜P1-finite element which has been recently proposed by Park ([13, 14]), we examine in detail the numerical behaviour of this element with special emphasis on the treatment of Dirichlet boundary conditions, ...

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Research paper thumbnail of Computational Fluid Dynamics of a Fatal Ruptured Anterior Communicating Artery Aneurysm

Journal of neurological surgery. Part A, Central European neurosurgery, 2017

Computational fluid dynamics (CFD) has been studied as a tool for the stratification of aneurysm ... more Computational fluid dynamics (CFD) has been studied as a tool for the stratification of aneurysm rupture risk. We performed CFD analysis in a patient operated on for a ruptured anterior communicating artery aneurysm. The point of rupture was identified during surgery. The aneurysm and blood vessels were segmented from computed tomography angiography to prepare a model for simulations. We found that the streamlines showed a concentrated inflow jet directed straight at the rupture point, and high wall shear stress was found at the point of rupture in the aneurysm sac. Thus specific local hemodynamics may be indicative of the aneurysm rupture site.

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Research paper thumbnail of Characterization of solid-fluid mixtures

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Research paper thumbnail of Further remarks on simple flows of fluids with pressure-dependent viscosities

Nonlinear Analysis: Real World Applications, 2011

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Research paper thumbnail of Numerical simulation and benchmarking of fluid-structure interaction with application to hemodynamics

Numerical techniques for solving the problem of fluid-structure interaction with an elastic mater... more Numerical techniques for solving the problem of fluid-structure interaction with an elastic material in a laminar incompressible viscous flow are described. An Arbitrary Lagrangian-Eulerian (ALE) formulation is employed in a fully coupled monolithic way, considering the problem as one continuum. The mathematical description and the numerical schemes are designed in such a way that more complicated constitutive relations (and more

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Research paper thumbnail of Numerical solution of fluid-structure interaction with applications in biomechanics

The 41st Annual SES Technical Meeting, 2004

In bioengineering applications problems of flow interacting with elastic solid are very common. W... more In bioengineering applications problems of flow interacting with elastic solid are very common. We formulate the problem of interaction between an incompressible fluid and an incompressible elastic material in the arbitrary Lagrangian-Eulerian formulation, including the possibility ...

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Research paper thumbnail of Morphological and Hemodynamic Changes during Cerebral Aneurysm Growth

Brain Sciences

Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic propert... more Computational fluid dynamics (CFD) has grown as a tool to help understand the hemodynamic properties related to the rupture of cerebral aneurysms. Few of these studies deal specifically with aneurysm growth and most only use a single time instance within the aneurysm growth history. The present retrospective study investigated four patient-specific aneurysms, once at initial diagnosis and then at follow-up, to analyze hemodynamic and morphological changes. Aneurysm geometries were segmented via the medical image processing software Mimics. The geometries were meshed and a computational fluid dynamics (CFD) analysis was performed using ANSYS. Results showed that major geometry bulk growth occurred in areas of low wall shear stress (WSS). Wall shape remodeling near neck impingement regions occurred in areas with large gradients of WSS and oscillatory shear index. This study found that growth occurred in areas where low WSS was accompanied by high velocity gradients between the aneurys...

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Research paper thumbnail of Tidal dissipation in Enceladus’ uneven, fractured ice shell

Icarus

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Research paper thumbnail of Plume Activity and Tidal Deformation on Enceladus Influenced by Faults and Variable Ice Shell Thickness

Astrobiology

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Research paper thumbnail of Mathematical Description of Soft Tissue Mechanics

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Research paper thumbnail of Introduction: Numerical Benchmarking of Fluid-Structure Interaction

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Research paper thumbnail of Numerical analysis and a-posteriori error control for a new nonconforming linear finite element on quadrilaterals

Starting with a short introduction of the new nonconforming linear quadrilateral ˜ P1-finite elem... more Starting with a short introduction of the new nonconforming linear quadrilateral ˜ P1-finite element which has been recently proposed by Park ((13, 14)), we examine in detail the numerical behaviour of this element with special emphasis on the treatment of Dirichlet boundary conditions, efficient matrix assembly, solver aspects and the use as Stokes element in CFD. Furthermore, we compare the

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Monolithic Fem Solver for an Ale Formulation of Fluid-Structure Interaction with Configuration for Numerical Benchmarking

We investigate a monolithic algorithm to solve the problem of time dependent interaction between ... more We investigate a monolithic algorithm to solve the problem of time dependent interaction between an incompressible viscous fluid and an elastic solid. The continuous formulation of the problem and its discretization is done in a monolithic way, treating the problem as one continuum. The Q2/P dis 1 finite elements are used for the discretization and an approximate Newton method with

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A monolithic FEM/Multigrid solver for ALE formulation of fluid structure interaction with application in biomechanics

We investigate a new method of solving the problem of fluid-structure interaction of an incompres... more We investigate a new method of solving the problem of fluid-structure interaction of an incompressible elastic object in laminar incompressible viscous flow. Our proposed method is based on a fully implicit, monolithic formulation of the problem in the arbitrary Lagrangian-Eulerian framework. High order FEM is used to obtain the discrete approximation of the problem. In order to solve the resulting

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Numerical analysis of a new time-stepping θ-scheme for incompressible flow simulations

In [13], we had performed numerical comparisons for different time stepping schemes for the incom... more In [13], we had performed numerical comparisons for different time stepping schemes for the incompressible Navier-Stokes equations. In this paper, we present the numerical analysis in the context of the Navier-Stokes equations for a new time-stepping θ-scheme which has been recently proposed by Glowinski [5]. Like the well-known classical Fractional-Step-θ-scheme which had been introduced by Glowinski [1], [4], too, and which is still one of the most popular time stepping schemes, with or without operator splitting techniques, this new scheme consists of 3 substeps with non-equidistant substepping to build one macro time step. However, in contrast to the Fractional-Step-θ-scheme, the second substep can be formulated as an extrapolation step for previously computed data only, and the two remaining substeps look like a Backward Euler step so that no expensive operator evaluations for the right hand side vector with older solutions, as for instance in the Crank-Nicolson scheme, have to...

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Research paper thumbnail of Numerical Simulation of Fluid Structure Interaction with Application to Aneurysm Hemodynamics

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Research paper thumbnail of The Computational Fluid Dynamics Rupture Challenge 2013-Phase I: Prediction of Rupture Status in Intracranial Aneurysms

AJNR. American journal of neuroradiology, Jan 11, 2014

Rupture risk assessment for intracranial aneurysms remains challenging, and risk factors, includi... more Rupture risk assessment for intracranial aneurysms remains challenging, and risk factors, including wall shear stress, are discussed controversially. The primary purpose of the presented challenge was to determine how consistently aneurysm rupture status and rupture site could be identified on the basis of computational fluid dynamics. Two geometrically similar MCA aneurysms were selected, 1 ruptured, 1 unruptured. Participating computational fluid dynamics groups were blinded as to which case was ruptured. Participants were provided with digitally segmented lumen geometries and, for this phase of the challenge, were free to choose their own flow rates, blood rheologies, and so forth. Participants were asked to report which case had ruptured and the likely site of rupture. In parallel, lumen geometries were provided to a group of neurosurgeons for their predictions of rupture status and site. Of 26 participating computational fluid dynamics groups, 21 (81%) correctly identified the ...

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Research paper thumbnail of Numerical Methods and Nature

Journal of Scientific Computing, 2006

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Research paper thumbnail of Numerical analysis for a new non-conforming linear finite element on quadrilaterals

Journal of Computational and Applied Mathematics, 2006

Starting with a short introduction of a new non-conforming linear quadrilateral View the MathML s... more Starting with a short introduction of a new non-conforming linear quadrilateral View the MathML source -finite element which has been recently proposed by Park [A study on locking phenomena in finite element methods, Ph.D. Thesis, Seoul National University, February 2002] and ...

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Research paper thumbnail of FEM multigrid techniques for fluid–structure interaction with application to hemodynamics

Applied Numerical Mathematics, 2012

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Research paper thumbnail of Numerical analysis and a-posteriori error control for a new nonconforming linear finite element on quadrilaterals

Starting with a short introduction of the new nonconforming linear quadrilateral ˜P1-finite eleme... more Starting with a short introduction of the new nonconforming linear quadrilateral ˜P1-finite element which has been recently proposed by Park ([13, 14]), we examine in detail the numerical behaviour of this element with special emphasis on the treatment of Dirichlet boundary conditions, ...

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Research paper thumbnail of Computational Fluid Dynamics of a Fatal Ruptured Anterior Communicating Artery Aneurysm

Journal of neurological surgery. Part A, Central European neurosurgery, 2017

Computational fluid dynamics (CFD) has been studied as a tool for the stratification of aneurysm ... more Computational fluid dynamics (CFD) has been studied as a tool for the stratification of aneurysm rupture risk. We performed CFD analysis in a patient operated on for a ruptured anterior communicating artery aneurysm. The point of rupture was identified during surgery. The aneurysm and blood vessels were segmented from computed tomography angiography to prepare a model for simulations. We found that the streamlines showed a concentrated inflow jet directed straight at the rupture point, and high wall shear stress was found at the point of rupture in the aneurysm sac. Thus specific local hemodynamics may be indicative of the aneurysm rupture site.

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Research paper thumbnail of Characterization of solid-fluid mixtures

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Further remarks on simple flows of fluids with pressure-dependent viscosities

Nonlinear Analysis: Real World Applications, 2011

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Numerical simulation and benchmarking of fluid-structure interaction with application to hemodynamics

Numerical techniques for solving the problem of fluid-structure interaction with an elastic mater... more Numerical techniques for solving the problem of fluid-structure interaction with an elastic material in a laminar incompressible viscous flow are described. An Arbitrary Lagrangian-Eulerian (ALE) formulation is employed in a fully coupled monolithic way, considering the problem as one continuum. The mathematical description and the numerical schemes are designed in such a way that more complicated constitutive relations (and more

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