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A quantitative performance analysis for Stokes solvers at the extreme scale [article]

Björn Gmeiner and Markus Huber and Lorenz John and Ulrich Rüde and Barbara Wohlmuth
2015 arXiv   pre-print
This article presents a systematic quantitative performance analysis for large finite element computations on extreme scale computing systems.  ...  Three parallel iterative solvers for the Stokes system, discretized by low order tetrahedral elements, are compared with respect to their numerical efficiency and their scalability running on up to 786  ...  The last three authors gratefully acknowledge the hospitality and support of the Institute for Mathematical Sciences of the National University of Singapore where part of this work was performed.  ... 
arXiv:1511.02134v1 fatcat:ilorgjuqqjg3ddruso7shcvjnu

Shape Project Anemos Srl Sunstar Simulation Of Unsteady Turbulent Flows For The Aerospace Industry

D. Modesti
2017 Zenodo  
The SUNSTAR project aims at improving the robustness and testing the predictive accuracy of an in-house CFD software for the simulation and the analysis of turbulent high-speed flows relevant for the aerospace  ...  The software kernel is a compressible parallel flow solver, incorporating state-of-the-art numerical methods and advanced features for the direct numerical simulation of supersonic flows.  ...  Acknowledgements This work was financially supported by the PRACE project funded in part by the EU's Horizon 2020 research and innovation programme (2014-2020) under grant agreement 653838.  ... 
doi:10.5281/zenodo.832057 fatcat:2emmwzid6zawdplm2qz7e2appe

Reduced model for capillary breakup with thermal gradients: Predictions and computational validation [article]

Isha Shukla, Fan Wang, Saviz Mowlavi, Amy Guyomard, Xiangdong Liang, Steven G. Johnson, J.-C. Nave
2021 arXiv   pre-print
We obtain excellent quantitative agreement for a wide range of experimentally relevant feed speeds.  ...  Owing to its low computational cost, the reduced model is therefore a useful tool for designing future experiments.  ...  Separately, a large-scale parallel solver for the 3D axisymmetric Stokes equations was developed in C, giving an accurate reference solution for the capillary breakup process and resulting particle size  ... 
arXiv:2104.11671v2 fatcat:264c6bytefegrmrs3miaxg6rnu

Textbook efficiency: massively parallel matrix-free multigrid for the Stokes system [article]

Nils Kohl, Ulrich Rüde
2020 arXiv   pre-print
The excellent node-level performance of the relevant compute kernels is presented via a roofline analysis.  ...  We employ textbook multigrid efficiency (TME), as introduced by Achi Brandt, to construct an asymptotically optimal monolithic multigrid solver for the Stokes system.  ...  (https: // for funding this project by providing computing time on the GCS Supercomputer SuperMUC-NG at Leibniz Supercomputing Centre (https: //  ... 
arXiv:2010.13513v1 fatcat:5efjox5ka5dkznt2dyxljcq6ua

TerraNeo—Mantle Convection Beyond a Trillion Degrees of Freedom [chapter]

Simon Bauer, Hans-Peter Bunge, Daniel Drzisga, Siavash Ghelichkhan, Markus Huber, Nils Kohl, Marcus Mohr, Ulrich Rüde, Dominik Thönnes, Barbara Wohlmuth
2020 Lecture Notes in Computational Science and Engineering  
This contribution reports on the TerraNeo project which delivered novel matrix-free geometric multigrid solvers for the Stokes system that forms the core of mantle convection models.  ...  Simulation of mantle convection on planetary scales is considered a grand-challenge application even in the exascale era.  ...  Summary of Project Results Efficiency of Solvers and Software A rigorous quantitative performance analysis lies at the heart of systematic research in large scale scientific computing.  ... 
doi:10.1007/978-3-030-47956-5_19 fatcat:4jhueyv5qrhfdkmpfxxv5lsmqa

Efficient Variable-Coefficient Finite-Volume Stokes Solvers

Mingchao Cai, Andy Nonaka, John B. Bell, Boyce E. Griffith, Aleksandar Donev
2014 Communications in Computational Physics  
and Poisson solvers for the velocity and pressure subproblems.  ...  We demonstrate that only a single cycle of a standard geometric multigrid algorithm serves as an effective inexact solver for each of these subproblems.  ...  [24] for a specific formulation. To avoid loss of accuracy, in extreme cases extended precision arithmetic may need to be used in the solver [24] .  ... 
doi:10.4208/cicp.070114.170614a fatcat:jbb7zkn3fjhnzduxpnxfvpvqsu

Linear stability of boundary layers under solitary waves

Joris C. G. Verschaeve, Geir K. Pedersen
2014 Journal of Fluid Mechanics  
The results are compared to key results of inviscid stability theory and validated by means of a direct numerical simulation using a Legendre-Galerkin spectral ele- ment Navier-Stokes solver.  ...  A change of frame of reference has been used to allow for a classical linear stability analysis without the need to redefine the notion of stability for this otherwise unsteady flow.  ...  A direct numerical simulation by means of a Navier-Stokes solver was performed to verify the results obtained by linear stability analysis. The present discussion is organized as follows.  ... 
doi:10.1017/jfm.2014.617 fatcat:hwmrz527afcsblruu5ejd2guxu

Development of a Stokes flow solver robust to large viscosity jumps using a Schur complement approach with mixed precision arithmetic

Mikito Furuichi, Dave A. May, Paul J. Tackley
2011 Journal of Computational Physics  
The usage of a high precision Krylov kernel is found to be useful for the solver associated with the velocity sub-problem.  ...  Within both of these methods, we utilize either the scaled BFBt, or an identity matrix scaled by the local cell viscosity (LV) to define a preconditioner for the Schur complement.  ...  This work was performed in the Institute of Geophysics ETH Zurich, during the research abroad program of the Japan Agency for Marine-Earth Science and Technology.  ... 
doi:10.1016/ fatcat:rjoblb7lrnfc5larevqdng5s4a

Tightly Coupled Atomistic-Continuum Simulations of Brain Blood Flow on Petaflop Supercomputers

Leopold Grinberg, Joseph A. Insley, Dmitry A. Fedosov, Vitali Morozov, Michael E. Papka, George Em Karniadakis
2012 Computing in science & engineering (Print)  
Finally, a need exists for quantitative data analysis tools that are suitable for operating on multiscale data and clearly presenting the scale interactions.  ...  U nderstanding physical phenomena at diverse scales has always been a great challenge.  ...  The visualization was performed on Eureka at the Argonne Leadership Computing Facility. Support was provided by the US  ... 
doi:10.1109/mcse.2012.127 fatcat:wctfb7cbjje7fdwk7xl3jhittq

Performance and Wake Analysis of Rotors in Axial Flight Using Computational Fluid Dynamics

Nik Ahmad Ridhwan Nik Mohd, George Barakos
2017 Journal of Aerospace Technology and Management  
In this paper, the steady Reynolds-Averaged Navier-Stokes Computational Fluid Dynamics solver Helicopter Multi-Block was used to predict the performance of rotors in axial flight.  ...  The detailed velocity field of the tip vortex for a rotor in hover was also investigated, and a strong self-similarity of the swirl velocity profile was found.  ...  AUTHOR'S CONTRIBUTION Mohd NARN performed the numerical calculation and prepared the figures; Barakos G conceived the idea and co-wrote the main text.  ... 
doi:10.5028/jatm.v9i2.623 fatcat:uodg6krtkzfhlhtkcn4knprfie

A FFT-accelerated multi-block finite-difference solver for massively parallel simulations of incompressible flows [article]

Pedro Costa
2021 arXiv   pre-print
We present a multi-block finite-difference solver for massively parallel Direct Numerical Simulations (DNS) of incompressible flows.  ...  Particular care was taken here, to guarantee the parallel performance of the multigrid solver when solving the reduced linear systems equations.  ...  The computing time for the scaling tests was provided by the Swedish National Infrastructure for Computing (SNIC), and the National Infrastructure for High-Performance Computing and Data Storage in Norway  ... 
arXiv:2106.03583v4 fatcat:vqlvtysmwbfgxir34afqftov3i

Wb-Sails: Modelling Sail Boat Performance In Hpc

Mikko Brummer
2017 Zenodo  
Coupled with a FEA solver, full fluid-structure analysis including optimization is possible.  ...  The code allows 6 degrees of freedom (DOF) for motion of the objects, for a realistic simulation of forces and moments around a boat moving in seaway.  ...  Acknowledgements This work was financially supported by the PRACE project funded in part by the EU's Horizon 2020 research and innovation programme (2014-2020) under grant agreement 653838.  ... 
doi:10.5281/zenodo.832060 fatcat:xhjw36jmmbb65ag3v4ln6luiuq

Modeling and Simulation of Piezoelectrically Agitated Acoustic Streaming on Microfluidic Biochips [chapter]

Harbir Antil, Andreas Gantner, Ronald H. W. Hoppe, Daniel Köster, Kunibert Siebert, Achim Wixforth
2008 Lecture Notes in Computational Science and Engineering  
Biochips, of the microarray type, are fast becoming the default tool for combinatorial chemical and biological analysis in environmental and medical studies.  ...  The mathematical model represents a multiphysics problem consisting of the piezoelectric equations coupled with multiscale compressible Navier-Stokes equations that have to be treated by an appropriate  ...  The work of the first author is further partially supported by the NSF under Grant-No. DMS-0511611  ... 
doi:10.1007/978-3-540-75199-1_36 fatcat:prmr4trvsnfaxa7mmzvvlzgnpu

Survivability of wave energy converters using CFD

E.J. Ransley, D. Greaves, A. Raby, D. Simmonds, M. Hann
2017 Renewable Energy  
The survivability of Wave Energy Converters (WECs) in extreme waves is a critical issue faced by developers; typically assessed via small scale physical experiments with considerable uncertainties.  ...  Two separate design waves, based on the 100 year wave at Wave Hub and using the NewWave formulation, have been reproduced numerically as have experiments in which a fixed truncated circular cylinder and  ...  Acknowledgements The authors would like to acknowledge the COAST Laboratory technical staff for their assistance in designing and running the physical experiments.  ... 
doi:10.1016/j.renene.2017.03.003 fatcat:ffiq4jssxzb2hiuswnlyxaqpl4

Benchmarking of Navier–Stokes codes for free surface simulations by means of a solitary wave

Paweł A. Wroniszewski, Joris C.G. Verschaeve, Geir K. Pedersen
2014 Coastal Engineering  
The paper presents a benchmark of four freely available solvers for Navier-Stokes equations: Gerris, OpenFOAM, Thétis and Truchas.  ...  The Navier-Stokes solvers use the finite volume discretization and free surface capturing techniques based on the volume-of-fluid (VOF) method.  ...  Acknowledgment The authors are grateful to Jose M. Gonzalez-Ondina and Stéphane Glockner for providing help with the Truchas and Thétis code, respectively.  ... 
doi:10.1016/j.coastaleng.2014.04.012 fatcat:dmjsjlcn4fffrhr4vv7zcndafe
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