TODAY: 56th NIA CFD Seminar Webcast: Accuracy-Preserving Boundary Quadrature for Edge-Based Finite-Volume Scheme: Third-order accuracy without curved elements by Hiro Nishikawa

December 16, 2014 - Leave a Response

56th NIA CFD Seminar

Highlights:

– 3rd-order accuracy (exactness for quadratic fluxes) proved for node-centered edge-based finite-volume(EBFV) scheme
- 3rd-order accuracy is lost if the interface flux is exact for quadratic fluxes
– A boundary closure formula discovered for 3rd-order EBFV scheme
– Single-node evaluation gives 3rd-order accuracy on flat uniform boundary grid in triangular grids.
- 3rd-order EBFV scheme doesn’t require curved elements.
– But a normal vector needs to be computed accurately by a quadratic interpolation.

Topic: Accuracy-Preserving Boundary Quadrature for Edge-Based Finite-Volume Scheme: Third-order accuracy without curved elements

Date: Tuesday, December 16, 2014

Time: 11:00am-noon (EST)

Room: NIA, Rm137

Speaker: Hiro Nishikawa

Speaker Bio: Dr. Hiroaki Nishikawa is Associate Research Fellow, NIA. He earned Ph.D. in Aerospace Engineering and Scientific Computing at the University of Michigan in 2001. He then worked as a postdoctoral fellow at the University of Michigan on adaptive grid methods, local preconditioning methods, multigrid methods, rotated-hybrid Riemann solvers, high-order upwind and viscous schemes, etc., and joined NIA in 2007. His area of expertise is the algorithm development for CFD, focusing on hyperbolic methods for robust, efficient, highly accurate viscous discretization schemes.

Abstract: This talk will discuss a third-order edge-based finite-volume scheme on unstructured grids. It will be shown why the edge-based scheme can be third-order and also why it cannot be third-order if the numerical flux is exact for quadratic fluxes. A general boundary flux quadrature formula is presented that preserves third-order accuracy at boundary nodes with linear elements. Numerical results show that the general formula as well as acccurate boundary normals are essential to achieve third-order accuracy for a curved boundary problem with linear elements.

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_logo

TOMORROW: 56th NIA CFD Seminar Webcast: Accuracy-Preserving Boundary Quadrature for Edge-Based Finite-Volume Scheme: Third-order accuracy without curved elements by Hiro Nishikawa

December 15, 2014 - Leave a Response

56th NIA CFD Seminar

Highlights:

– 3rd-order accuracy (exactness for quadratic fluxes) proved for node-centered edge-based finite-volume(EBFV) scheme
- 3rd-order accuracy is lost if the interface flux is exact for quadratic fluxes
– A boundary closure formula discovered for 3rd-order EBFV scheme
– Single-node evaluation gives 3rd-order accuracy on flat uniform boundary grid in triangular grids.
- 3rd-order EBFV scheme doesn’t require curved elements.
– But a normal vector needs to be computed accurately by a quadratic interpolation.

Topic: Accuracy-Preserving Boundary Quadrature for Edge-Based Finite-Volume Scheme: Third-order accuracy without curved elements

Date: Tuesday, December 16, 2014

Time: 11:00am-noon (EST)

Room: NIA, Rm137

Speaker: Hiro Nishikawa

Speaker Bio: Dr. Hiroaki Nishikawa is Associate Research Fellow, NIA. He earned Ph.D. in Aerospace Engineering and Scientific Computing at the University of Michigan in 2001. He then worked as a postdoctoral fellow at the University of Michigan on adaptive grid methods, local preconditioning methods, multigrid methods, rotated-hybrid Riemann solvers, high-order upwind and viscous schemes, etc., and joined NIA in 2007. His area of expertise is the algorithm development for CFD, focusing on hyperbolic methods for robust, efficient, highly accurate viscous discretization schemes.

Abstract: This talk will discuss a third-order edge-based finite-volume scheme on unstructured grids. It will be shown why the edge-based scheme can be third-order and also why it cannot be third-order if the numerical flux is exact for quadratic fluxes. A general boundary flux quadrature formula is presented that preserves third-order accuracy at boundary nodes with linear elements. Numerical results show that the general formula as well as acccurate boundary normals are essential to achieve third-order accuracy for a curved boundary problem with linear elements.

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_logo

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