2026-09-19T20:04:56Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/106377 2023-07-11 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Fischer, Paul F Fischer, Paul F Pearlstein, Arne J Matalon, Moshe Olson, Luke N Lu, Li 2020-03-02T22:15:08Z 2020-03-02T22:15:08Z 2022-03-03T10:15:19Z 2019-12-05 2019-12 We develop and implement algorithms for highly-scalable high-order compressible flow simulation using the discontinuous Galerkin spectral element method. The algorithms are designed for simulation of compressible turbulence in realistic engineering geometries that are relevant to a broad range of mechanical engineering applications. Such problems are difficult because of high computational costs and stringent requirements for accurate integration over a wide range of space- and time-scales. Features of this solver include exponential spatial convergence, fast matrix-free operator evaluation, implicit time-stepping schemes, highly-scalable iterative solvers, effective stabilization techniques, and moving-mesh capabilities. Novel nonlinear filter-based artificial viscosity methods have been developed for effective regularization of challenging scalar transport problems in high-order methods and have found application in shock-capturing for the compressible flow solver. Moving-mesh capabilities via the arbitrary Lagrangian-Eulerian method are verified and have enabled simulation of complex engineering applications with moving geometries such as flows in internal combustion engines. Spatial (exponential) and temporal (up to fourth-order) convergence rates of the underlying numerical methods are established. Scalability of the solver, up to realizable strong-scale limits, establishes that the code is suitable for large-scale parallel computing applications. Several proposed preconditioning strategies are evaluated. The solver is demonstrated on a variety of flow problems, such as nearly-incompressible flows, supersonic flows, high Reynolds number flows, shock problems, and moving-geometry problems. Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-12-01 The student, Li Lu, accepted the attached license on 2019-12-05 at 10:25. The student, Li Lu, submitted this Dissertation for approval on 2019-12-05 at 10:38. This Dissertation was approved for publication on 2019-12-05 at 13:19. DSpace SAF Submission Ingestion Package generated from Vireo submission #14713 on 2020-02-28 at 17:23:31 Made available in DSpace on 2020-03-02T22:15:08Z (GMT). No. of bitstreams: 2 LU-DISSERTATION-2019.pdf: 16816874 bytes, checksum: 9fa57050e06a045525200a0a817ebf93 (MD5) LICENSE.txt: 4202 bytes, checksum: 13ce14ecb0e6a35fb1dc2d5dea6d8892 (MD5) Previous issue date: 2019-12-05 Embargo set by: Seth Robbins for item 113919 Lift date: 2022-03-02T22:15:21Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 113919 Lift date: 2022-03-02T22:18:25Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system U of I Only Restriction Lifted for Item 113919 on 2022-03-03T10:15:19Z. application/pdf http://hdl.handle.net/2142/106377 en Copyright 2019 Li Lu Discontinuous Galerkin, compressible flow solver, high-order A discontinuous Galerkin spectral element method compressible flow solver text text Mechanical Sci & Engineering Mechanical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.