Boris Diskin
Resident at: NIA
100 Exploration Way, Hampton, VA 23666
Tel: (757) 325-6902; Fax: (757) 325-6988
Email: bdiskin@nianet.org
Research Interests
- Numerical optimization methods
- Analysis of unstructured-grid discretizations
- Multigrid solvers on structured/unstructured grids
- Multiscale methods for modeling turbulent flows
- Multiscale methods for simulations of advanced materials
Current Research
· Adjoint-Based Methodology for Time-Dependent Optimal Control (AMTOC). The goal of this project is to develop the methodology for adjoint-based optimization of unsteady flows and demonstrate its applications to design optimization in large-scale fluid dynamics computations. Large-scale shape optimizations have been recently demonstrated for turbulent flows over a tiltrotor in a pitch-up maneuver and over a fighter jet with simulated aeroelastic motions. The current focus of the project is on developing memory and CPU-time saving techniques to make AMTOC computations more efficient. This research has been published in 3 AIAA papers (AIAA-2008-5857, AIAA-2009-1169, and AIAA-2009-3802) and two journal publications (to appear in AIAA Journal and in Journal on Computational Physics). This study is conducted in collaborations with E. J. Nielson (NASA LaRC) and N. K. Yamaleev and K. Pathak (NC A&T)
· Efficient finite-volume discretizations on unstructured grids. This study aims at developing finite-volume discretizations suitable for efficient, robust, and uniformly 2nd order accurate solutions for turbulent flows on general unstructured grids with a minimal set of constraints. Practical computational grids are unstructured, anisotropic, mixed-element, moving, agglomerated, overlapped, deformed, but still capable to produce accurate solutions for very complicated flows. In this project we analyze existing discretization methods and develop improved methods with low-complexity, verified accuracy, and efficient solvers. This research has been published in 3 AIAA papers (AIAA-2008-666, AIAA-2009-597, and AIAA-2010-1079) and in 3 journal publications (two in AIAA Journal 2008 and to appear in 2010 and one in Applied Numerical Mathematics, 2009). This study is conducted in collaborations with FUN3D development group at NASA LaRC and with Nishikawa H. (NIA)
· Multigrid solvers on unstructured grids. This study is concerned with developing efficient agglomeration multigrid solvers for turbulent flows on general unstructured grids. Novel efficient methods for analysis of multigrid solutions on unstructured grids have been developed and implemented. Efficient agglomeration multigrid solvers have been demonstrated for diffusion on highly anisotropic grids and for inviscid flows on general unstructured grids. This research has been published in 2 AIAA papers (AIAA-2009-4138 and AIAA-2010-4731) and 2 journal publications (to appear in AIAA Journal and Computers & Fluids). This study is conducted in collaborations with Thomas J. L (NASA LaRC) and Nishikawa H. (NIA)
Publications
J. L. Thomas, B. Diskin, and H. Nishikawa “A critical study of agglomerated multigrid methods for diffusion on highly stretched grids,” invited paper, submitted for publication to Computers & Fluids
E. J. Nielsen, B. Diskin, and N. K. Yamaleev, “Discrete adjoint-based design optimization of unsteady turbulent flows on dynamic unstructured grids,” AIAA Journal; doi: 10.2514/1.J050035
H. Nishikawa, B. Diskin, and J. L. Thomas, “A critical study of agglomerated multigrid methods for diffusion,” AIAA Journal; doi: 10.2514/1.J050055
Yamaleev N. K., Diskin B., and Nielsen E. J., “Local-in-time adjoint-based methods for design optimization of unsteady flows,” submitted for publication to Journal of Computational Physics
Diskin B., Thomas J. L., Nielsen E. J., Nishikawa H., and White J. A., “Comparison of node-centered and cell-centered unstructured finite-volume discretizations: viscous fluxes,” accepted for publication to AIAA Journal
Diskin B. and Thomas J. L. “Notes on accuracy of finite-volume discretization schemes on irregular grids,” Applied Numerical Mathematics; doi: 10.1016/j.apnum.2009.12.001
Thomas J. L., Diskin B., and Ramsey C. L., “Towards Verification of Unstructured-Grid Solvers,” AIAA Journal, 46, pp. 3070-3079, 2008
W. Liao, B. Diskin, Y. Peng, L.-S. Luo , “Textbook-efficiency multigrid solver for three-dimensional unsteady compressible Navier–Stokes equations,” Journal of Computational Physics, 227(15), pp. 7160-7177, 2008
Diskin B., Thomas J. L., and Mineck R. E., “On general quantitative analysis methods for multigrid solutions,” SIAM Journal on Scientific Computing, 27(1), pp. 108-129, 2005
Diskin B. and Thomas J. L., “Comparison of Cell-Centered and Node-Centered Unstructured Finite-Volume Discretizations: Inviscid Fluxes,” AIAA-2010-1079; 48th AIAA Aerospace Sciences Meeting, Orlando, FL, Jan 2010