Hydrodynamic processes in the advanced stages of massive star evolution
Casey Meakin , University of Chicago
Stellar evolution is currently an exercise in spherical symmetry. The hydrodynamic processes taking place in stars, however, do not share this symmetry. Simplified models of the underlying hydrodynamics have been formulated, and have been quite successful in explaining the gross properties of stars. These models fail, however, when confronted with the ever more stringent observational tests that are becoming available. These failures have given birth to simplistic prescriptions for additional mixing at the boundaries of convection zones dubbed "overshoot" and "penetration". These obfuscating notions need to be replaced with an underlying physical picture. A powerful approach for investigating the complex flow present in stellar interiors is multi-dimensional hydrodynamic simulation. In this talk I will present an overview of the multi-dimensional simulations that we have been performing in the context of pre-supernova models and discuss how we are incorporating our new understanding into 1D stellar evolution codes.