Scaling and spatial intermittency of thermal dissipation in turbulent convection
KAUST DepartmentFluid and Plasma Simulation Group (FPS)
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
KAUST Grant NumberProject No. k1052
Preprint Posting Date2019-04-06
Online Publication Date2019-07-16
Print Publication Date2019-07
Embargo End Date2020-07-16
Permanent link to this recordhttp://hdl.handle.net/10754/656183
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AbstractWe derive scaling relations for the thermal dissipation rate in the bulk and in the boundary layers for moderate and large Prandtl number (Pr) convection. Using direct numerical simulations of Rayleigh-Bénard convection, we show that the thermal dissipation in the bulk is suppressed compared to passive scalar dissipation. The suppression is stronger for large Pr. We further show that the dissipation in the boundary layers dominates that in the bulk for both moderate and large Pr. The probability distribution functions of thermal dissipation rate, both in the bulk and in the boundary layers, are stretched exponential, similar to passive scalar dissipation.
CitationBhattacharya, S., Samtaney, R., & Verma, M. K. (2019). Scaling and spatial intermittency of thermal dissipation in turbulent convection. Physics of Fluids, 31(7), 075104. doi:10.1063/1.5098073
SponsorsWe thank A. Pandey, A. Guha, and R. Samuel for useful discussions. Our numerical simulations were performed on Shaheen II at Kaust Supercomputing Laboratory, Saudi Arabia, under the Project No. k1052. This work was supported by the research Grant No. PLANEX/PHY/2015239 from Indian Space Research Organisation, India, and by the Department of Science and Technology, India (Grant No. INT/RUS/RSF/P-03), and the Russian Science Foundation, Russia (Grant No. RSF-16-41-02012), for the Indo-Russian project.
JournalPhysics of Fluids