31st NIA CFD Seminar

Topic: Adjoint-based optimization of unsteady turbulent flows: Recent advances and current challenges

Date: Tuesday, April 16, 2013

Time:11:00am-noon (EST),

Location: NIA room 137

Speaker: Boris Diskin

Biography: Dr. Boris Diskin is a Research Fellow at NIA. He earned Ph.D. in Applied Mathematics at The Weizmann Institute of Science, Israel in 1998. He was a Senior Research Scientist at ICASE and joined NIA from its inception in 2003. His area of expertise is adjoint-based optimization and grid adaptation methods, finite-volume discretizations, and multigrid methods.

Abstract: This presentation is a rehearsal of the talk to be presented at “Weizmann workshop 2013 on multilevel computational methods and optimization”. This talk reviews a discrete adjoint-based methodology for unsteady turbulent flows on three-dimensional overset unstructured grids. The methodology provides a general framework for performing discretely consistent and highly efficient sensitivity analysis for problems involving arbitrary combinations of overset unstructured grids that can be static, undergoing rigid or deforming motions, or any combination of thereof. The methodology is especially effective for gradient-based optimization with many design parameters. The implementation is verified with a complex-variable approach and illustrated by large-scale optimization examples. It will be shown that in the current high-performance computing environment, the memory is not a limiting factor for practical large-scale applications. Other challenges, such as significant CPU time and possible instabilities in application to chaotic flows, will be discussed.

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/