Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection
The movement of heat in a convecting system is typically described by the nondimensional Nusselt number, which involves an average over both space and time. In direct numerical simulations of turbulent flows, there is considerable variation in the contributions to the Nusselt number, both because of...
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| Format: | Article |
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MDPI AG
2020-08-01
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| Series: | Fluids |
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| Online Access: | https://www.mdpi.com/2311-5521/5/3/127 |
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| author | Jane Pratt Angela Busse Wolf-Christian Müller |
| author_facet | Jane Pratt Angela Busse Wolf-Christian Müller |
| author_sort | Jane Pratt |
| collection | DOAJ |
| description | The movement of heat in a convecting system is typically described by the nondimensional Nusselt number, which involves an average over both space and time. In direct numerical simulations of turbulent flows, there is considerable variation in the contributions to the Nusselt number, both because of local spatial variations due to plumes and because of intermittency in time. We develop a statistical approach to more completely describe the structure of heat transfer, using an exit-distance extracted from Lagrangian tracer particles, which we call the Lagrangian heat structure. In a comparison between simulations of homogeneous turbulence driven by Boussinesq convection, the Lagrangian heat structure reveals significant non-Gaussian character, as well as a clear trend with Prandtl number and Rayleigh number. This has encouraging implications for simulations performed with the goal of understanding turbulent convection in natural settings such as Earth’s atmosphere and oceans, as well as planetary and stellar dynamos. |
| first_indexed | 2024-03-10T18:01:01Z |
| format | Article |
| id | doaj.art-7649083b17c84e519ec7b711fedab7aa |
| institution | Directory Open Access Journal |
| issn | 2311-5521 |
| language | English |
| last_indexed | 2024-03-10T18:01:01Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fluids |
| spelling | doaj.art-7649083b17c84e519ec7b711fedab7aa2023-11-20T08:53:01ZengMDPI AGFluids2311-55212020-08-015312710.3390/fluids5030127Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq ConvectionJane Pratt0Angela Busse1Wolf-Christian Müller2Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USAJames Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UKCenter for Astronomy and Astrophysics, ER 3-2, TU Berlin, Hardenbergstr. 36, 10623 Berlin, GermanyThe movement of heat in a convecting system is typically described by the nondimensional Nusselt number, which involves an average over both space and time. In direct numerical simulations of turbulent flows, there is considerable variation in the contributions to the Nusselt number, both because of local spatial variations due to plumes and because of intermittency in time. We develop a statistical approach to more completely describe the structure of heat transfer, using an exit-distance extracted from Lagrangian tracer particles, which we call the Lagrangian heat structure. In a comparison between simulations of homogeneous turbulence driven by Boussinesq convection, the Lagrangian heat structure reveals significant non-Gaussian character, as well as a clear trend with Prandtl number and Rayleigh number. This has encouraging implications for simulations performed with the goal of understanding turbulent convection in natural settings such as Earth’s atmosphere and oceans, as well as planetary and stellar dynamos.https://www.mdpi.com/2311-5521/5/3/127Lagrangian transportgeophysical fluid flowsconvectionturbulencestatistical methods |
| spellingShingle | Jane Pratt Angela Busse Wolf-Christian Müller Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection Fluids Lagrangian transport geophysical fluid flows convection turbulence statistical methods |
| title | Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection |
| title_full | Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection |
| title_fullStr | Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection |
| title_full_unstemmed | Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection |
| title_short | Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection |
| title_sort | lagrangian statistics of heat transfer in homogeneous turbulence driven by boussinesq convection |
| topic | Lagrangian transport geophysical fluid flows convection turbulence statistical methods |
| url | https://www.mdpi.com/2311-5521/5/3/127 |
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