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Related papers: Overshooting by differential heating

200 papers

Employing numerical simulations, we provide an accurate insight into the of heat transfer mechanisms in the Rayleigh-B\'enard convection of concentrated emulsions with finite-size droplets. We focus on the unsteady dynamics characterizing…

Fluid Dynamics · Physics 2024-02-14 Francesca Pelusi , Stefano Ascione , Mauro Sbragaglia , Massimo Bernaschi

Recent hydrodynamical simulations of convection in a solar-like model suggest that penetrative convective flows at the boundary of the convective envelope modify the thermal background in the overshooting layer. Based on these results, we…

Solar and Stellar Astrophysics · Physics 2022-03-14 Baraffe I , Constantino T , Clarke J , Le Saux A , Goffrey T , Guillet T , Pratt J , Vlaykov D. G

The mixed convection flow in a plane channel with adiabatic boundaries is examined. The boundaries have an externally prescribed relative velocity defining a Couette-like setup for the flow. A stationary flow regime is maintained with a…

Fluid Dynamics · Physics 2023-10-04 A. Barletta , M. Celli , S. Lazzari , P. V. Brandão

Demixing of binary fluids subjected to slow temperature ramps shows repeated waves of nucleation which arise as a consequence of the competition between generation of supersaturation by the temperature ramp and relaxation of supersaturation…

Statistical Mechanics · Physics 2012-10-16 Izabella J. Benczik , Jürgen Vollmer

During most stages of stellar evolution the nuclear burning of lighter to heavier elements results in a radial composition profile which is stabilizing against buoyant acceleration, with light material residing above heavier material.…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. Mocák , Casey A. Meakin , E. Müller , L. Siess

The stability of a rotating flow in a triaxial ellipsoidal shell with an imposed temperature difference between inner and outer boundaries is studied numerically. We demonstrate that (i) a stable temperature field encourages the tidal…

Classical Physics · Physics 2010-10-01 David Cébron , Pierre Maubert , Michael Le Bars

Heat transfer to a granular flow is comprised of two resistances in series: near the wall and within the bulk particle bed, neither of which is well understood due to the lack of experimental probes to separate their respective…

Previous studies have suggested a crossover from superdiffusive to normal heat transport in one-dimensional (1D) anharmonic oscillator systems with a double-well type interatomic interaction like $V(\xi)=-\xi^2/2+\xi^4/4$, when the system…

Statistical Mechanics · Physics 2016-04-22 Daxing Xiong

The coexistence of motions on various scales is a remarkable feature of solar convection, which should be taken into account in analyses of the dynamics of magnetic fields. Therefore, it is important to investigate the factors responsible…

Solar and Stellar Astrophysics · Physics 2015-01-15 O. V. Shcheritsa , A. V. Getling , O. S. Mazhorova

In a recent paper (El Omari and Le Guer, IJHMT, 53, 2010) we have investigated mixing and heat transfer enhancement in a mixer composed of two circular rods maintained vertically in a cylindrical tank. The rods and tank can rotate around…

Fluid Dynamics · Physics 2010-12-14 Kamal El Omari , Yves Le Guer

It has been proposed that mixing induced by convective overshoot can disrupt the inward propagation of carbon deflagrations in super-asymptotic giant branch stars. To test this theory, we study an idealized model of convectively bounded…

Thermal convection is one of the main mechanisms of heat transport and mixing in stars in general and also in the photospheric layers which emit the radiation that we observe with astronomical instruments. The present lecture notes first…

Solar and Stellar Astrophysics · Physics 2020-02-03 Friedrich Kupka

There is strong observational evidence that the convective cores of intermediate-mass and massive main sequence stars are substantially larger than those predicted by standard stellar-evolution models. However, it is unclear what physical…

Solar and Stellar Astrophysics · Physics 2024-08-20 R. Andrassy , G. Leidi , J. Higl , P. V. F. Edelmann , F. R. N. Schneider , F. K. Roepke

Convection in the cores of massive stars becomes anisotropic when they rotate. This anisotropy leads to a misalignment of the thermal gradient and the thermal flux, which in turn results in baroclinicity and circulation currents in the…

Solar and Stellar Astrophysics · Physics 2018-10-26 Adam S. Jermyn , Christopher A. Tout , Shashikumar M. Chitre

We investigate how rotating convection responds to the imposition of a latitudinally-varying heat flux at the base of the convective layer. This study is motivated by the solar near-surface shear layer, whose flows are thought to transition…

Solar and Stellar Astrophysics · Physics 2025-12-15 Kinfe Teweldebirhan , Rituparna Curt , Nicholas A. Featherstone

Galactic winds are crucial to the cosmic cycle of matter, transporting material out of the dense regions of galaxies. Observations show the coexistence of different temperature phases in such winds, which is not easy to explain. We present…

Layer formation in a thermally destabilized fluid with stable density gradient has been observed in laboratory experiments and has been proposed as a mechanism for mixing molecular weight in late stages of stellar evolution in regions which…

Astrophysics · Physics 2007-05-23 Joseph A. Biello

We demonstrate the ability to experimentally measure fluctuations of the convective heat transfer coefficient at the wall in a turbulent boundary layer. For this, we measure two-dimensional fields of wall-temperature fluctuations beneath a…

Fluid Dynamics · Physics 2025-02-04 Firoozeh Foroozan , Andrea Ianiro , Stefano Discetti , Woutijn J. Baars

In this paper, four sets of evolutionary models are computed with different values of the mixing length parameter $\alpha_{\rm p}$ and the overshooting parameter $\delta_{\rm ov}$. The properties of the convective cores and the convective…

Solar and Stellar Astrophysics · Physics 2015-05-14 Jin Jie , Chunhua Zhu , Guoliang Lv

The absorption of light or radiation drives turbulent convection inside stars, supernovae, frozen lakes and the Earth's mantle. In these contexts, the goal of laboratory and numerical studies is to determine the relation between the…

Fluid Dynamics · Physics 2021-01-08 Simon Lepot , Sébastien Aumaître , Basile Gallet