Seminar 2016-01 Alireza Mazaheri: High-Order Residual-Distribution Schemes for Discontinuous Problems on Irregular Triangular Grids

Topic: 69th NIA CFD Seminar: High-Order Residual-Distribution Schemes for Discontinuous Problems on Irregular Triangular Grids

Date: Tuesday, January 26, 2016

Time: 11:00am-noon (EST)

Room: NIA, Rm 137

Speaker: Alireza Mazaheri

Webcast Link:

Abstract: In this talk, we construct second- and third-order non-oscillatory shock-capturing hyperbolic residual-distribution schemes for irregular triangular grids, extending our previously proposed high-order schemes [J. Comput. Phys., 300 (2015), 455—491] to discontinuous problems. We present extended first-order N- and Rusanov-scheme formulations for a hyperbolic advection-diffusion system. We then construct second- and third-order non-oscillatory hyperbolic residual-distribution schemes by blending the non-monotone second- and third-order schemes with the extended first-order schemes as typically done in the residual-distribution schemes, and examine them for discontinuous problems on irregular triangular grids. We also propose to use the Rusanov scheme to avoid non-physical shocks in combination with an improved characteristics-based nonlinear wave sensor for detecting shocks, compression, and expansion regions. We then verify the design order of accuracy of these blended schemes on irregular triangular grids.

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.