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High performance adaptive finite element methods for turbulent fluid flow
KTH, Skolan för datavetenskap och kommunikation (CSC), Numerisk analys, NA.ORCID-id: 0000-0002-5020-1631
2011 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Understanding the mechanics of turbulent fluid flow is of key importance for industry and society as for example in aerodynamics and aero-acoustics. The massive computational cost for resolving all turbulent scales in a realistic problem makes direct numerical simulation of the underlying Navier-Stokes equations impossible. Recent advances in adaptive finite element methods offer a new powerful tool in Computational Fluid Dynamics (CFD). The computational cost for simulating turbulent flow can be minimized where the mesh is adaptively resolved, based on a posteriori error control. These adaptive methods have been implemented for efficient serial computations, but the extension to an efficient parallel solver is a challenging task.

This work concerns the development of an adaptive finite element method for modern parallel computer architectures. We present efficient data structures and data decomposition methods for distributed unstructured tetrahedral meshes. Our work also concerns an efficient parallellization of local mesh refinement methods such as recursive longest edge bisection.

We also address the load balance problem with the development of an a priori predictive dynamic load balancing method. Current results are encouraging with almost linear strong scaling to thousands of cores on several modern architectures.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH Royal Institute of Technology , 2011. , s. xii, 29
Serie
Trita-CSC-A, ISSN 1653-5723 ; 2011:02
Nationell ämneskategori
Beräkningsmatematik
Identifikatorer
URN: urn:nbn:se:kth:diva-30277ISBN: 978-91-7415-878-6 (tryckt)OAI: oai:DiVA.org:kth-30277DiVA, id: diva2:399309
Presentation
2011-03-14, E3, KTH, Osquarsbacke 14, Stockholm, 10:15 (Engelska)
Opponent
Handledare
Anmärkning
QC 20110223Tillgänglig från: 2011-02-23 Skapad: 2011-02-21 Senast uppdaterad: 2011-02-23Bibliografiskt granskad
Delarbeten
1. Framework For Massively Parallel Adaptive Finite Element Computational Fluid Dynamics On Tetrahedral Meshes
Öppna denna publikation i ny flik eller fönster >>Framework For Massively Parallel Adaptive Finite Element Computational Fluid Dynamics On Tetrahedral Meshes
2012 (Engelska)Ingår i: SIAM Journal on Scientific Computing, ISSN 1064-8275, E-ISSN 1095-7197, Vol. 34, nr 1, s. C24-C42Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In this paper we describe a general adaptive finite element framework for unstructured tetrahedral meshes without hanging nodes suitable for large scale parallel computations. Our framework is designed to scale linearly to several thousands of processors, using fully distributed and efficient algorithms. The key components of our implementation, local mesh refinement and load balancing algorithms, are described in detail. Finally, we present a theoretical and experimental performance study of our framework, used in a large scale computational fluid dynamics computation, and we compare scaling and complexity of different algorithms on different massively parallel architectures.

Nyckelord
adaptive methods, load balancing, unstructured local mesh refinement
Nationell ämneskategori
Beräkningsmatematik
Identifikatorer
urn:nbn:se:kth:diva-30284 (URN)10.1137/100800683 (DOI)000300937500028 ()2-s2.0-84861384674 (Scopus ID)
Forskningsfinansiär
Swedish e‐Science Research Center
Anmärkning

QC 20120326

Tillgänglig från: 2011-02-21 Skapad: 2011-02-21 Senast uppdaterad: 2017-12-11Bibliografiskt granskad
2. Adaptive Computation of Aeroacoustic Sources for Rudimentary Landing Gear
Öppna denna publikation i ny flik eller fönster >>Adaptive Computation of Aeroacoustic Sources for Rudimentary Landing Gear
2010 (Engelska)Ingår i: Benchmark problems for Airframe Noise Computations I, Stockholm 2010, 2010Konferensbidrag, Publicerat paper (Övrigt vetenskapligt)
Nationell ämneskategori
Beräkningsmatematik
Identifikatorer
urn:nbn:se:kth:diva-30282 (URN)
Anmärkning
QC 20110224Tillgänglig från: 2011-02-21 Skapad: 2011-02-21 Senast uppdaterad: 2011-02-24Bibliografiskt granskad
3. A computational study of turbulent flow separation for a circular cylinder using skin friction boundary conditions
Öppna denna publikation i ny flik eller fönster >>A computational study of turbulent flow separation for a circular cylinder using skin friction boundary conditions
2011 (Engelska)Ingår i: Quality And Reliability Of Large-Eddy Simulations II, Springer Netherlands, 2011, Vol. 16, nr 1, s. 57-68Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

In this paper we present a computational study of turbulent flow separation for a circular cylinder at high Reynolds numbers. We use a stabilized finite element method together with skin friction boundary conditions, where we study flow separation with respect to the decrease of a friction parameter. In particular, we consider the case of zero friction corresponding to pure slip boundary conditions, for which we observe an inviscid separation mechanism of large scale streamwise vortices, identified in our earlier work. We compare our computational results to experiments for very high Reynolds numbers. In particular, we connect the pattern of streamwise vorticity in our computations to experimental findings of spanwise 3d cell structures reported in the literature.

Ort, förlag, år, upplaga, sidor
Springer Netherlands, 2011
Serie
ERCOFTAC Series, ISSN 1382-4309 ; 16
Nyckelord
turbulent boundary layer, flow separation, General Galerkin method, a posteriori error estimation, adaptive finite element method, skin firction boundary conditions
Nationell ämneskategori
Beräkningsmatematik
Identifikatorer
urn:nbn:se:kth:diva-30280 (URN)10.1007/978-94-007-0231-8_5 (DOI)000306194400005 ()2-s2.0-84964887723 (Scopus ID)978-94-007-0230-1 (ISBN)
Konferens
2nd Workshop on Quality and Reliability of Large-Eddy Simulations, Univ Pisa, Pisa, Italy,Sep 09-11, 2009
Anmärkning

QC 20110224

Tillgänglig från: 2011-02-21 Skapad: 2011-02-21 Senast uppdaterad: 2013-12-13Bibliografiskt granskad

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Jansson, Niclas

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