Abstract

I will discuss the process of convective penetration driven by turbulent convection  in stars. The complex dynamics resulting from turbulent convection penetration in stable layers is a major process in various geophysical and astrophysical environments. This process is particularly important in stellar interiors because convective penetration drives the transport of chemical species and heat, strongly affecting the structure and the evolution of stars. It also generates internal waves which can be detected at the stellar surface. The treatment of this process is one of the oldest unsolved problems of stellar structure and evolution theory. I will present a study of convective penetration based on multi-dimensional stellar structure models performed with a new fully compressible hydrodynamics time implicit code, the MUSIC code. I will discuss recent simulations devoted to the study of convection in the Sun and solar-like stars. Our results suggest that penetrative convective flows at the boundary of a convective envelope modify the thermal background in the overshooting layer and produce a local heating. This heating can reduce the sound-speed discrepancy usually reported between solar models and the Sun’s structure inferred from helioseismology. I will also discuss preliminary results for convective cores in a broad range of massive stars and current difficulties for numerical simulations to predict the amount of convective boundary mixing required to reproduce observations.