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Related papers: A two-stream formalism for the convective Urca pro…

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In this paper we describe our convective hydrocodes for radial stellar pulsation. We adopt the Kuhfuss (1986) model of convection, reformulated for the use in stellar pulsation hydrocodes. Physical as well as numerical assumptions of the…

Astrophysics · Physics 2008-10-13 R. Smolec , P. Moskalik

Pulsating white dwarfs provide constraints to the evolution of progenitor stars. We revise He-burning stellar models, with particular attention to core convection and to its connection with the nuclear reactions powering energy generation…

Astrophysics · Physics 2009-11-07 Oscar Straniero , Inma Dominguez , Gianluca Imbriani , Luciano Piersanti

Convection is a key transport phenomenon important in many different areas, from hydrodynamics and ocean circulation to planetary atmospheres or stellar physics. However its microscopic understanding still remains challenging. Here we…

Statistical Mechanics · Physics 2022-07-29 P. L. Garrido , P. I. Hurtado

Hydrodynamic simulations of neutron star mergers rely on the clear separation between the strong-interaction, weak-interaction, and hydrodynamic timescales. In this effective framework, weak Urca interactions are typically the slowest…

High Energy Astrophysical Phenomena · Physics 2026-03-17 Jamie M. Karthein , Maneesha Sushama Pradeep , Rachel Steinhorst

Non-isothermal particles suspended in a fluid lead to complex interactions -- the particles respond to changes in the fluid flow, which in turn is modified by their temperature anomaly. Here, we perform a novel proof-of-concept numerical…

Fluid Dynamics · Physics 2022-12-06 Lokahith Agasthya , Andreas Bartel , Luca Biferale , Matthias Ehrhardt , Federico Toschi

The convective overshoot mixing plays an important role in stellar structure and evolution. However, the overshoot mixing is a long standing problem. The uncertainty of the overshoot mixing is one of the most uncertain factors in stellar…

Solar and Stellar Astrophysics · Physics 2013-07-16 Q. S. Zhang

Despite the appearance of two- and three-dimensional models thanks to the rapid growth of computing performance, numerical hydrocodes used to model radial stellar pulsations still apply a one-dimensional stellar envelope model without any…

Solar and Stellar Astrophysics · Physics 2023-03-27 Gábor B. Kovács , Róbert Szabó , János Nuspl

We establish rigorous lower bounds on the speed of traveling fronts and on the bulk burning rate in reaction-diffusion equation with passive advection. The non-linearity is assumed to be of either KPP or ignition type. We consider two main…

Analysis of PDEs · Mathematics 2015-06-26 Alexander Kiselev , Leonid Ryzhik

We present a new way of modeling turbulent thermonuclear deflagration fronts in Chandrasekhar-mass white dwarfs, consisting of carbon and oxygen, undergoing a type Ia supernova explosion. Our approach is a front capturing/tracking hybrid…

Astrophysics · Physics 2007-05-23 W. Hillebrandt , M. Reinecke , J. C. Niemeyer

Two dimensional hydrodynamical simulations of convective oxygen burning shell in the presupernova evolution of a 20 solar-mass star are extended to later times. We used the VULCAN code to simulate longer evolution times than previously…

Astrophysics · Physics 2009-10-31 S. M. Asida , David Arnett

Interstitial fluid flow is a feature of many solid tumours. In vitro Experiments have shown that such fluid flow can direct tumour cell movement upstream or downstream depending on the balance between the competing mechanisms of tensotaxis…

Cell Behavior · Quantitative Biology 2024-02-21 Yaron Ben-Ami , Joe M. Pitt-Francis , Philip K. Maini , Helen M. Byrne

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

We present here, for the first time, a 2D study of the overshoot convective mechanism in nova outbursts for a wide range of possible compositions of the layer underlying the accreted envelope. Previous surveys studied this mechanism only…

Solar and Stellar Astrophysics · Physics 2012-10-04 Ami S. Glasner , Eli Livne , James W. Truran

We study a system describing the dynamics of a two-phase flow of incompressible viscous fluids influenced by the convective heat transfer of Caginalp-type. The separation of the fluids is expressed by the order parameter which is of diffuse…

Analysis of PDEs · Mathematics 2023-08-15 Šárka Nečasová , John Sebastian H. Simon

The amount and spatial pattern of heat extracted from cores of terrestrial planets is ultimately controlled by the thermal structure of the lower rocky mantle. Using the most common model to tackle this problem, a rapidly rotating and…

Earth and Planetary Astrophysics · Physics 2016-01-26 Wieland Dietrich , Kumiko Hori , Johannes Wicht

We introduce two simplified nuclear networks that can be used in hydrostatic carbon burning reactions occurring in white dwarf interiors. They model the relevant nuclear reactions in carbon-oxygen white dwarfs (COWDs) approaching ignition…

Solar and Stellar Astrophysics · Physics 2015-05-19 Francisco Förster , Pierre Lesaffre , Philipp Podsiadlowski

We develop a relativistic multifluid dynamics appropriate for describing neutron star cores at finite temperatures based on Carter's convective variational procedure. The model includes seven fluids, accounting for both normal and…

High Energy Astrophysical Phenomena · Physics 2020-09-14 Peter B. Rau , Ira Wasserman

We argue that bulk spiral flows are ubiquitous in the cool cores (CCs) of clusters and groups of galaxies. Such flows are gauged by spiral features in the thermal and chemical properties of the intracluster medium, by the multi-phase…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Uri Keshet

This work presents a unified numerical framework for simulating incompressible flows within the coupled fluid-porous-medium system and involving heat and solute transport and phase-changing process. A complete set of governing equations is…

Fluid Dynamics · Physics 2026-01-28 Rongfu Guo , Yantao Yang

Convective cores are the hydrogen reservoirs of main sequence stars that are more massive than around 1.2 solar masses. The characteristics of the cores have a strong impact on the evolution and structure of the star. However, such results…

Solar and Stellar Astrophysics · Physics 2023-08-09 Anthony Noll , Sébastien Deheuvels