Wednesday 14 Oct 2015: Seminar: Stellar Evolution and Hydrodynamics: 321D link
Dr Raphael Hirschi - University of Keele
Physics, 4th floor 14:00-15:00
Stars play an important role in the universe through the light they shine, the elements they produce and the explosion that possibly marks their death. Stars are complex objects, which we would like to model using three-dimensional (3D) magneto-hydrodynamics (MHD) simulations. Their lifetime are unfortunately more than ten orders of magnitude longer than the convective motion timescale in hydrodynamics simulations. This forces stellar evolution modellers to mostly do one-dimensional (1D) simulations of stars, relying on approximate prescriptions for multi-D effects such as convection and rotation.
The continuous computing power increase has now reached the point where we can constrain and improve prescriptions used in 1D stellar evolution models with targeted 3D simulations and the interpretation of their results into theoretical frameworks, sometimes referred to as the 321D link. One of the aims of the SHYNE (Stellar HYdrodynamics, Nucleosynthesis and Evolution) research project is to undertake such 3D simulations and develop improved prescriptions for 1D stellar evolution models. After a general introduction, I will present the SHYNE project and initial results of two groups of 3D simulations, one targeted at constraining convective boundary mixing and the other at constraining the dynamical shear induced by strong differential axial rotation in massive stars.