Backscatter in stratified turbulence
| dc.contributor.author | Khani, Sina | |
| dc.contributor.author | Waite, Michael L | |
| dc.date.accessioned | 2021-09-27T14:50:13Z | |
| dc.date.available | 2021-09-27T14:50:13Z | |
| dc.date.issued | 2016-11 | |
| dc.description | The final publication is available at Elsevier via http://dx.doi.org/https://doi.org/10.1016/j.euromechflu.2016.06.012. © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ | en |
| dc.description.abstract | In this paper, kinetic and potential energy transfers around a spectral test fil ter scale in direct numerical simulations of decaying stratified turbulence are studied in both physical and spectral domains. It is shown that while the domain-averaged effective subgrid scale energy transfer in physical space is a net downscale cascade, it is actually a combination of large values of downscale and upscale transfer, i.e. forward- and backscatter, in which the forward scatter is slightly dominant. Our results suggest that spectral backscatter in stratified turbulence depends on the buoyancy Reynolds number Reb and the filtering scale ∆test. When the test filter scale ∆test is around the dissipation scale Ld, transfer spectra show spectral backscatter from sub-filter to intermediate scales, as reported elsewhere. However, we find that this spectral backscatter is due to viscous effects at vertical scales around the test filter. It is also shown that there is a non-local energy transfer from scales larger than the buoyancy scale Lb to small scales.The effective turbulent Prandtl number spectra demonstrate that the assumption P rt ≈ 1 is reasonable for the local energy transfer. | en |
| dc.description.sponsorship | Funder 1, SciNet is funded by the Canada Foundation for Innovation under the auspices of Compute Canada || Funder 2, the Government of Ontario || Funder 3, Ontario Research Fund–Research Excellence || Funder 4 , the University of Toronto || Funder 5, Financial support from the Natural Sciences and Engineering Research Council of Canada (grant number RGPIN-386456-2015) is gratefully acknowledged. | en |
| dc.identifier.uri | https://doi.org/10.1016/j.euromechflu.2016.06.012 | |
| dc.identifier.uri | http://hdl.handle.net/10012/17537 | |
| dc.language.iso | en | en |
| dc.publisher | Elsevier | en |
| dc.relation.ispartofseries | European Journal of Mechanics - B/Fluids; | |
| dc.rights | Attribution-NonCommercial-NoDerivatives 4.0 International | * |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | * |
| dc.subject | Stratified turbulence | en |
| dc.subject | Direct numerical simulations | en |
| dc.subject | up- and downscale energy transfer | en |
| dc.title | Backscatter in stratified turbulence | en |
| dc.type | Article | en |
| dcterms.bibliographicCitation | Khani, S., & Waite, M. L. (2016). Backscatter in stratified turbulence. European Journal of Mechanics - B/Fluids, 60, 1–12. https://doi.org/10.1016/j.euromechflu.2016.06.012 | en |
| uws.contributor.affiliation1 | Faculty of Mathematics | en |
| uws.contributor.affiliation2 | Applied Mathematics | en |
| uws.peerReviewStatus | Reviewed | en |
| uws.scholarLevel | Faculty | en |
| uws.typeOfResource | Text | en |