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Related papers: Testing the 3-equation Kuhfuss Convection Model us…

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Convection is ubiquitous in stellar and planetary interiors where it likely plays an integral role in the generation of magnetic fields. As the interiors of these objects remain hidden from direct observation, numerical models of convection…

Solar and Stellar Astrophysics · Physics 2026-01-22 Brandon J. Lazard , Nicholas A. Featherstone , Jonathan M. Aurnou

Sub-Neptunes and Neptunes are often modeled with distinct, fully convective layers. Yet, there are several arguments for compositions gradients that can inhibit convection. In these regions, energy transport depends on the thermal…

Earth and Planetary Astrophysics · Physics 2026-05-29 Mark Eberlein , Ravit Helled

Understanding solar turbulent convection and its influence on differential rotation has been a challenge over the past two decades. Current models often overestimate giant convection cells amplitude, leading to an effective Rossby number…

Solar and Stellar Astrophysics · Physics 2025-03-12 Quentin Noraz , Allan Sacha Brun , Antoine Strugarek

We adopted an unstructured hydrodynamical solver CharLES to the problem of global convection in the Sun. With the aim to investigate the properties of solar turbulent convection and reproduce differential rotation pattern. We performed…

Solar and Stellar Astrophysics · Physics 2014-12-24 Vyacheslav Olshevsky , Chunlei Liang , Frank Ham

The goal of this research is to investigate how well various turbulence models can describe physical properties of the upper convective boundary layer of the Sun. An accurate modeling of the turbulence motions is necessary for understanding…

Astrophysics · Physics 2009-11-13 L. Jacoutot , A. G. Kosovichev , A. Wray , N. N. Mansour

This paper describes the first steps of development of a new multidimensional time implicit code devoted to the study of hydrodynamical processes in stellar interiors. The code solves the hydrodynamical equations in spherical geometry and…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 M. Viallet , I. Baraffe , R. Walder

In this paper, we calibrate the coefficients for the one-dimensional Reynolds stress model with the data generated from the three-dimensional numerical simulations of upward overshooting in turbulent compressible convection. It has been…

Solar and Stellar Astrophysics · Physics 2020-06-17 Tao Cai

Relations between temperature, T, and optical depth, tau, are often used for describing the photospheric transition from optically thick to optically thin in stellar structure models. We show that this is well justified, but also that…

Solar and Stellar Astrophysics · Physics 2015-06-19 Regner Trampedach , Robert F. Stein , Jørgen Christensen-Dalsgaard , Åke Nordlund , Martin Asplund

This work investigates the properties of convection in stars with particular emphasis on entrainment across the upper convective boundary (CB). Idealised simulations of turbulent convection in the O-burning shell of a massive star are…

Solar and Stellar Astrophysics · Physics 2016-11-03 Samuel Jones , Robert Andrassy , Stou Sandalski , Austin Davis , Paul Woodward , Falk Herwig

Continued progress in observational stellar astrophysics requires a deep understanding of the underlying convection dynamics. We present results of realistic 3D radiative hydrodynamic simulations of the outer layers of a moderate mass star…

Solar and Stellar Astrophysics · Physics 2016-04-27 Irina N. Kitiashvili , Alexander G. Kosovichev , Nagi N. Mansour , Alan A. Wray

(abridged) Context: Rotation is thought to influence the size of convective eddies and the efficiency of convective energy transport in the deep convection zones of stars. Rotationally constrained convection has been invoked to explain the…

Solar and Stellar Astrophysics · Physics 2023-10-20 Petri J. Käpylä

A major weakness in one-dimensional (1D) stellar structure and evolution modeling is the simplified treatment of convection, which leads to erroneous near-surface stratification and considerable uncertainties in predicted effective…

We analyze stellar convection with the aid of 3D hydrodynamic simulations, introducing the turbulent cascade into our theoretical analysis. We devise closures of the Reynolds-decomposed mean field equations by simple physical modeling of…

Astrophysics · Physics 2011-02-11 David Arnett , Casey Meakin , P. A. Young

Stellar evolution models of massive stars are important for many areas of astrophysics, for example nucleosynthesis yields, supernova progenitor models and understanding physics under extreme conditions. Turbulence occurs in stars primarily…

Solar and Stellar Astrophysics · Physics 2016-03-23 Andréa Cristini , Casey Meakin , Raphael Hirschi , David Arnett , Cyril Georgy , Maxime Viallet

As a step toward a complete theoretical integration of 3D compressible hydrodynamic simulations into stellar evolution, convection at the surface and sub-surface layers of the Sun is re-examined, from a restricted point of view, in the…

Solar and Stellar Astrophysics · Physics 2014-11-20 W. David Arnett , Casey Meakin , Patrick A. Young

Context. Synthetic model atmosphere calculations are still the most commonly used tool when determining precise stellar parameters and stellar chemical compositions. Besides three-dimensional models that consistently solve for hydrodynamic…

Solar and Stellar Astrophysics · Physics 2015-05-20 X. S. Wu , S. Alexeeva , L. Mashonkina , L. Wang , G. Zhao , F. Grupp

The near-surface layers of cool main-sequence stars are structured by convective flows, which are overshooting into the atmosphere. The flows and the associated spatio-temporal variations of density and temperature affect spectral line…

Solar and Stellar Astrophysics · Physics 2013-08-27 Benjamin Beeck , Robert H. Cameron , Ansgar Reiners , Manfred Schüssler

Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations, and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive…

Solar and Stellar Astrophysics · Physics 2015-06-15 Regner Trampedach , Martin Asplund , Remo Collet , Åke Nordlund , Robert F. Stein

Helioseismic inversions reveal a major discrepancy in sound speed between the Sun and the standard solar model just below the base of solar convection zone. We demonstrate that this discrepancy is caused by the inherent shortcomings of the…

Solar and Stellar Astrophysics · Physics 2012-10-17 Chunguang Zhang , Licai Deng , Darun Xiong , Jørgen Christensen-Dalsgaard

The development of 2D and 3D simulations of solar convection has lead to a picture of convection quite unlike the usually assumed Kolmogorov spectrum turbulent flow. We investigate the impact of this changed structure on the dissipation…

Astrophysics · Physics 2012-05-14 Kaloyan Penev , Dimitar Sasselov , Frank Robinson , Pierre Demarque