A5057184591- Advanced Numerical Methods in Computational Mathematics
- Fluid Dynamics and Turbulent Flows
- Computational Fluid Dynamics and Aerodynamics
- Fluid Dynamics and Vibration Analysis
- Numerical methods in engineering
- Electromagnetic Simulation and Numerical Methods
- Matrix Theory and Algorithms
- Model Reduction and Neural Networks
- Cardiac Imaging and Diagnostics
- Renal function and acid-base balance
- Cardiac Health and Mental Health
- Pregnancy and preeclampsia studies
- Cardiac, Anesthesia and Surgical Outcomes
- Birth, Development, and Health
- Advanced Mathematical Modeling in Engineering
- Gestational Diabetes Research and Management
- Numerical methods for differential equations
- Cardiovascular Function and Risk Factors
- Electromagnetic Scattering and Analysis
- Computer Graphics and Visualization Techniques
- Lattice Boltzmann Simulation Studies
- Cardiovascular Disease and Adiposity
- Wind and Air Flow Studies
- Aerodynamics and Acoustics in Jet Flows
- Distributed and Parallel Computing Systems
Czech Academy of Sciences, Institute of Mathematics
2013-2024
Czech Technical University in Prague
2004-2022
Czech Academy of Sciences
2009-2021
University of Manchester
2017-2019
University of Ottawa
1985
Charles University
1964
The automated finite element analysis of complex CAD models using boundary-fitted meshes is rife with difficulties. Immersed methods are intrinsically more robust but usually less accurate. In this work, we introduce an efficient, robust, high-order immersed method for models. Our approach relies on three adaptive structured grids: a geometry grid representing the implicit geometry, discretising physical fields and quadrature evaluating integrals. sparse VDB (Volumetric Dynamic B+ tree) that...
The recent version of the Parallel Linear Algebra Software for Multicore Architectures (PLASMA) library is based on tasks with dependencies from OpenMP standard. main functionality presented. Extensive benchmarks are targeted three multicore and manycore architectures, namely, an Intel Xeon, Xeon Phi, IBM POWER 8 processors.
A discontinuous outcome of vortex-identification methods called the disappearing vortex problem (DVP) has been already found for swirling strength criterion and Rortex (later renamed as Liutex) method. Here, opposite property reflecting situation that DVP cannot be any input data, is, non-existence DVP, is examined proved valid selected criteria based on velocity-gradient tensor, including Q, lambda-2, triple decomposition For Q-criterion method, it done directly, whereas shown using a proof...
An easy-to-interpret kinematic quantity measuring the average corotation of material line segments near a point is introduced and applied to vortex identification. At given point, vector defined as instantaneous local rigid-body rotation over “all planar cross sections” passing through examined point. The vortex-identification method based on one-parameter, region-type sensitive axial stretching rate well inner configuration velocity gradient tensor. derived from well-defined interpretation...
Direct consequences stem from the close relation between recently proposed vortex vector (Rortex) and swirling strength. It is shown that these vortex-identification methods share some relevant properties: (i) both provide same and, practically, largest region, (ii) allow an unlimited uniaxial stretching described by axisymmetric strain rate, so strain-rate magnitude inside a may become much larger (without any limitation) than vorticity magnitude, (iii) exhibit discontinuous outcome, known...
By considering a uniaxial stretching coupled with an inevitable uniform radial contraction for incompressible flow, straightforward comparison of the response several popular vortex-identification criteria and recently proposed vortex vector (Rortex) is presented. In addition, outcome triple-decomposition method in terms residual vorticity tensor employed due to its planar coincidence Rortex. The sensitivity examined schemes significantly differs and, consequently, reopens persisting problem...
We discuss aspects of implementation and performance parallel iterative solution techniques applied to low Reynolds number flows around fixed moving rigid bodies. The incompressible Navier–Stokes equations are discretised with Taylor-Hood finite elements in combination a semi-implicit pressure-correction method. resulting sequence convection–diffusion Poisson solved preconditioned Krylov subspace methods. To achieve overall scalability we consider new auxiliary algorithms for mesh handling...
We extend the Balancing Domain Decomposition by Constraints (BDDC) method to flows in porous media discretised mixed-hybrid finite elements with combined mesh dimensions. Such discretisations appear when major geological fractures are modelled 1D or 2D inside three-dimensional domains. In this set-up, global problem as well substructure problems have a symmetric saddle-point structure, containing `penalty' block due combination of meshes. show that can be reduced means iterative...
Abstract Within the framework of finite element method problems with corner‐like singularities (e.g. on well‐known L‐shaped domain) are most often solved by adaptive strategy: mesh near corners is refined according to a posteriori error estimates. In this paper we present an alternative approach. For flow domains corner use priori estimates and asymptotic expansion solution derive algorithm for refining corner. It gives very precise in cheap way. We some numerical results. Copyright © 2005...
A new analysis of the vortex-identification <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>Q</mml:mi></mml:math>-criterion and its recent modifications is presented. In this unified framework based on different approaches to averaging cross-sectional balance between vorticity strain rate in 3D, relations among existing are derived. addition, a method spherical proposed. It applicable compressible flows, it inherits duality property which allows use for identifying...
Abstract We deal with 2D flows of incompressible viscous fluids high Reynolds numbers. Galerkin Least Squares technique stabilization the finite element method is studied and its modification described. present a number numerical results obtained by developed method, showing contribution to solving Several recommendations remarks are included. interested in positive as well negative aspects stabilization, which cannot be divorced. Copyright © 2005 John Wiley & Sons, Ltd.