Resolving Entropy Growth from Iterative Methods
(2023)- Abstract
- We consider entropy conservative and dissipative discretizations of nonlinear conservation laws with implicit time discretizations and investigate the influence of iterative methods used to solve the arising nonlinear equations. We show that Newton's method can turn an entropy dissipative scheme into an anti-dissipative one, even when the iteration error is smaller than the time integration error. We explore several remedies, of which the most performant is a relaxation technique, originally designed to fix entropy errors in time integration methods. Thus, relaxation works well in consort with iterative solvers, provided that the iteration errors are on the order of the time integration method. To corroborate our findings, we consider... (More)
- We consider entropy conservative and dissipative discretizations of nonlinear conservation laws with implicit time discretizations and investigate the influence of iterative methods used to solve the arising nonlinear equations. We show that Newton's method can turn an entropy dissipative scheme into an anti-dissipative one, even when the iteration error is smaller than the time integration error. We explore several remedies, of which the most performant is a relaxation technique, originally designed to fix entropy errors in time integration methods. Thus, relaxation works well in consort with iterative solvers, provided that the iteration errors are on the order of the time integration method. To corroborate our findings, we consider Burgers' equation and nonlinear dispersive wave equations. We find that entropy conservation results in more accurate numerical solutions than non-conservative schemes, even when the tolerance is an order of magnitude larger. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/7a549c89-9e4b-48dc-ad1a-c1b437e49966
- author
- Linders, Viktor LU ; Ranocha, Hendrik LU and Birken, Philipp LU
- organization
- publishing date
- 2023
- type
- Working paper/Preprint
- publication status
- published
- subject
- publisher
- arXiv.org
- DOI
- 10.48550/arXiv.2302.13579
- project
- Olinjära vågor och entropistabil iteration
- language
- English
- LU publication?
- yes
- id
- 7a549c89-9e4b-48dc-ad1a-c1b437e49966
- date added to LUP
- 2023-09-01 11:31:41
- date last changed
- 2023-10-11 09:10:38
@misc{7a549c89-9e4b-48dc-ad1a-c1b437e49966, abstract = {{We consider entropy conservative and dissipative discretizations of nonlinear conservation laws with implicit time discretizations and investigate the influence of iterative methods used to solve the arising nonlinear equations. We show that Newton's method can turn an entropy dissipative scheme into an anti-dissipative one, even when the iteration error is smaller than the time integration error. We explore several remedies, of which the most performant is a relaxation technique, originally designed to fix entropy errors in time integration methods. Thus, relaxation works well in consort with iterative solvers, provided that the iteration errors are on the order of the time integration method. To corroborate our findings, we consider Burgers' equation and nonlinear dispersive wave equations. We find that entropy conservation results in more accurate numerical solutions than non-conservative schemes, even when the tolerance is an order of magnitude larger.}}, author = {{Linders, Viktor and Ranocha, Hendrik and Birken, Philipp}}, language = {{eng}}, note = {{Preprint}}, publisher = {{arXiv.org}}, title = {{Resolving Entropy Growth from Iterative Methods}}, url = {{http://dx.doi.org/10.48550/arXiv.2302.13579}}, doi = {{10.48550/arXiv.2302.13579}}, year = {{2023}}, }