on the publication serverTitle data
Bätge, Tobias ; Wilczek, Michael:
Small-scale averaging coarse-grains passive scalar turbulence.
In: Physical Review Fluids.
Vol. 6
(2021)
Issue 6
.
- No. 064503.
ISSN 2469-990X
DOI: https://doi.org/10.1103/PhysRevFluids.6.064503
Abstract in another language
Scalar fields which are subject to turbulent mixing typically feature a broad range of scales. When focusing on the large-scale dynamics, it remains a question how to effectively parametrize the small scales. Here, we address this question within the framework of a stochastic, one-dimensional passive scalar model. We show that small-scale averaging, i.e., an ensemble average over small-scale velocity fluctuations, results in an effective diffusivity reminiscent of phenomenological eddy viscosity models, while reducing the effective Reynolds number of the advecting velocity field. Based on that, we establish a filtering procedure that exactly maps second-order statistics of the fully resolved passive scalar field to the one obtained by small-scale averaging. Using fully resolved simulations, we show that small-scale averaging also captures higher-order large-scale statistics of passive scalar fields.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Institutions of the University: | Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Theoretical Physics I > Chair Theoretical Physics I - Univ.-Prof. Dr. Michael Wilczek Profile Fields > Advanced Fields > Nonlinear Dynamics |
| Result of work at the UBT: | No |
| DDC Subjects: | 500 Science > 530 Physics |
| Date Deposited: | 23 Feb 2022 12:59 |
| Last Modified: | 23 Feb 2022 12:59 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/67587 |
