Speaker
Mr
Andrea Cristini
(Keele University)
Description
Stellar models are important for many areas of astrophysics, for example nucleosynthesis yields, supernova progenitor models and understanding physics at extreme conditions. One of the longest standing problems with stellar evolution models is the treatment of convection. To study convection and turbulent motions in stellar interiors, detailed 3D hydrodynamical simulations are needed.
Simulations for a resolution study on the carbon shell of massive stars will be presented. Initial conditions are taken from a 15 solar mass stellar model evolved using the Geneva Stellar Evolution code (Eggenberger et. al., 2008, Ap&SS, 316, 43-54). Implicit Large Eddy simulations are computed using the hydrodynamics code PROMPI (Meakin and Arnett, 2007, ApJ, 667, 448-475). These simulations have been run on the Data Centric cluster (COSMA) within the STFC DiRAC facility.
The results are analysed within the framework of one-dimensional Reynolds-Averaged Navier-Stokes equations (Chassaing et. al., 2002), where the fields within these equations are decomposed into mean and fluctuating components. We investigate the process of turbulent entrainment at convective boundaries. We find that our models are within the equilibrium entrainment regime (Fedorovich et. al., 2004, J. Atmos. Sci., 61, 281), and also partially agree with the well known meteorological entrainment law (Garcia and Mellado, 2014, J. Atmos. Sci., 1935-1955).
By comparing with stellar evolution codes we hope to gain valuable insight into new prescriptions for convective boundary mixing within massive stellar models. This research will be valuable to the astronomy community as the carbon shell has never been studied in this context before.
Author
Mr
Andrea Cristini
(Keele University)
Co-authors
Dr
Casey Meakin
(University of Arizona)
Dr
Cyril Georgy
(University of Geneva)
Prof.
David Arnett
(University of Arizona)
Dr
Maxime Viallet
(Max-Planck-Institut fur Astrophysik)
Dr
Raphael Hirschi
(Keele University)
