TODAY: 76th NIA CFD Seminar Webcast: High-Order Discontinuous-Galerkin Schemes using Hyperbolic First-Order System Approach: same DoF as conventional but more accurate by Alireza Mazaheri

May 18, 2016 - Leave a Response

76th NIA CFD Seminar

Topic: High-Order Discontinuous-Galerkin Schemes using Hyperbolic First-Order System Approach: same DoF as conventional but more accurate

Date: Wednesday, May 18, 2016

Time: 11:00am-noon (EST)

Room: NIA, Rm137

Speaker: Alireza Mazaheri

Speaker Bio: Dr. Alireza Mazaheri is a Computational Aerothermodynamicist at NASA Langley Research center since 2006. Prior to that he worked at Parsons Inc. (as a research engineer), was a postdoctoral fellow at Pittsburgh University (from 2004-2005) and a National Research Council (NRC) postdoctoral fellow at the US Department of Energy (from 2003-2004). He earned PhD from Clarkson University in Mechanical Engineering, MS from Shiraz University in Computational Thermo-Fluid Engineering, and BS from Guilan University in Fluid Mechanics. Alireza has been involved in several NASA programs/projects, including the Space Shuttle, Orion Multi-Purpose Crew Vehicle (MPCV), Dream Chaser, Hypersonic Inflatable Aerodynamic Decelerator (HIAD), High Energy Atmospheric Reentry Test (HEART), etc. His current research interests are on development of high-order methods that are capable in producing accurate and noise-free solution gradients (e.g., velocity gradients, heat flux, shear stresses, etc.) on irregular tetrahedral elements.

Abstract: We propose arbitrary high-order discontinuous Galerkin (DG) schemes that are designed based on a first-order hyperbolic advection-diffusion formulation of the target governing equations. We present, in details, the efficient construction of the proposed high-order schemes (called DG-H), and show that these schemes have the same number of global degrees-of-freedom as comparable conventional high-order DG schemes, produce the same or higher order of accuracy solutions and solution gradients, are exact for exact polynomial functions, and do not need a second-derivative diffusion operator. We also present construction of a Weighted Essentially Non-Oscillatory (WENO) limiter for the proposed DG-H schemes. We demonstrate that the constructed high-order schemes give excellent quality solution and solution gradients on irregular triangular elements. Finally, we make some comparisons with conventional DG and interior-penalty schemes.

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

niacfds_square

TOMORROW: 76th NIA CFD Seminar Webcast: High-Order Discontinuous-Galerkin Schemes using Hyperbolic First-Order System Approach: same DoF as conventional but more accurate by Alireza Mazaheri

May 17, 2016 - Leave a Response

76th NIA CFD Seminar

Topic: High-Order Discontinuous-Galerkin Schemes using Hyperbolic First-Order System Approach: same DoF as conventional but more accurate

Date: Wednesday, May 18, 2016

Time: 11:00am-noon (EST)

Room: NIA, Rm137

Speaker: Alireza Mazaheri

Speaker Bio: Dr. Alireza Mazaheri is a Computational Aerothermodynamicist at NASA Langley Research center since 2006. Prior to that he worked at Parsons Inc. (as a research engineer), was a postdoctoral fellow at Pittsburgh University (from 2004-2005) and a National Research Council (NRC) postdoctoral fellow at the US Department of Energy (from 2003-2004). He earned PhD from Clarkson University in Mechanical Engineering, MS from Shiraz University in Computational Thermo-Fluid Engineering, and BS from Guilan University in Fluid Mechanics. Alireza has been involved in several NASA programs/projects, including the Space Shuttle, Orion Multi-Purpose Crew Vehicle (MPCV), Dream Chaser, Hypersonic Inflatable Aerodynamic Decelerator (HIAD), High Energy Atmospheric Reentry Test (HEART), etc. His current research interests are on development of high-order methods that are capable in producing accurate and noise-free solution gradients (e.g., velocity gradients, heat flux, shear stresses, etc.) on irregular tetrahedral elements.

Abstract: We propose arbitrary high-order discontinuous Galerkin (DG) schemes that are designed based on a first-order hyperbolic advection-diffusion formulation of the target governing equations. We present, in details, the efficient construction of the proposed high-order schemes (called DG-H), and show that these schemes have the same number of global degrees-of-freedom as comparable conventional high-order DG schemes, produce the same or higher order of accuracy solutions and solution gradients, are exact for exact polynomial functions, and do not need a second-derivative diffusion operator. We also present construction of a Weighted Essentially Non-Oscillatory (WENO) limiter for the proposed DG-H schemes. We demonstrate that the constructed high-order schemes give excellent quality solution and solution gradients on irregular triangular elements. Finally, we make some comparisons with conventional DG and interior-penalty schemes.

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

niacfds_square

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