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73rd NIA CFD Seminar Webcast: Superconvergent HDG Methods on General Polyhedral/Polygonal Meshes by Ke Shi
March 9, 2016

73rd NIA CFD Seminar

Topic: Superconvergent HDG Methods on General Polyhedral/Polygonal Meshes

Date: Wednesday, March 23, 2016

Time: 11:00am-noon (EST)

Room: NIA, Rm137

Speaker: Ke Shi

Speaker Bio: Dr. Shi got his PhD at the University of Minnesota supervised by Bernardo Cockburn, in 2012. He spent three years at the Texas A&M University as a visiting assistant professor. In 2016, he joined the department of Mathematics and Statistics of the Old Dominion University. His research covers a wide range of interests in numerical analysis and scientific computing, with a focus on hybridizable DG methods, multiscale finite element methods for flow problems in heterogeneous media.

Abstract: The hybridizable DG methods (HDG) was first introduced by Cockburn et al. in 2009. Since then it has been extensively developed by many colleagues in this area. It has gained lots of attention due to its unique features comparing with conventional methods (CG, DG, mixed methods etc). Roughly speaking, HDG methods . do share with mixed methods their superior convergence properties and can be implemented as efficiently as the hybridized mixed methods while retaining the advantages typical of the DG methods. In this talk, we will discuss a new class of HDG methods for many linear and nonlinear problems. A main feature of this approach is that the method provides optimal approximations for all unknowns on general polyhedral/polygonal meshes.

Additional information, including the webcast link, can be found at the NIA CFD Seminar website, which is temporarily located at

http://www.hiroakinishikawa.com/niacfds/index.html

 
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TODAY: 60th NIA CFD Seminar Webcast: M4D, an Open Source Research CFD Code for the Calculation of Classical and Turbulent/Transitional Flows by Joan G. Moore and John Moore
August 4, 2015

60th NIA CFD Seminar

Topic: M4D, an Open Source Research CFD Code for the Calculation of Classical and Turbulent/Transitional Flows

Date: Tuesday, August 4, 2015

Time: 11:00am-noon (EST)

Room: NIA, Rm137

Speaker: Joan G. Moore

Speaker Bio: It is fifty years since Joan and John Moore met in M.I.T.’s Gas Turbine Laboratory. John had come with a B.Sc. (Eng.) in Mechanical Engineering from Imperial College, London to obtain an S.M. and then an Sc.D from M.I.T. Joan with a B.S. in Applied Mathematics from M.I.T., had the job of writing computer codes and helping Graduate students with theirs. Thus began a life-long CFD and turbulence modeling collaboration. John is currently a Professor Emeritus of Mechanical Engineering at Virginia Tech. Their first ‘retirement’ project, their book “Functional Reynolds Stress Modeling” was published in 2006. And now Joan has written her 4th CFD code, M4D, but her first one unfettered by external sponsorship.

Abstract: M4D features unsteady convection adapted control volumes and the MARV/MARVS Reynolds stress models. Convection adapted control volumes are a paradigm shift in CFD. Used with tri-linear discretization of convected properties in space over a fixed grid (formally 3-d 2nd-order accurate), they provide a balance between accuracy and stability not found in fixed volume methods. The MARV/MARVS Reynolds stress models are advanced turbulence models which calculate transition naturally based on an understanding of homogeneous shear flow at high dimensionless strain rates.
The presentation will concentrate on the convection adapted control volumes – the method, the combination of stability and accuracy, with the examples of an inviscid Kelvin-Helmholtz shear layer instability and near-DNS of flow in a square channel. The steady flow Reynolds stress model examples of transitional flow and heat transfer in a turbine cascade (Butler et al.) and of a backward facing step (Kasagi) also use the convection adapted control volumes.

Additional information, including the webcast link, can be found at the NIA CFD Seminar website, which is temporarily located at

http://www.hiroakinishikawa.com/niacfds/index.html

 
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