Simulations of hydrodynamic phenomena in stellar interiors

This thesis presents multidimensional hydrodynamic simulations of stellar interiors with a focus on dynamical phenomena at low Mach numbers using the Seven-League Hydro (SLH) code. A better understanding of these phenomena is crucial to improve the modeling of stellar evolution. It is demonstrated that suitable numerical methods are required to avoid that numerical artifacts and spurious dissipation dominate the actual physical flow. Three-dimensional simulations of convective helium shell burning are used to measure the entrainment of mass into the convective region. This aids the parametrization of entrainment in one-dimensional evolution calculations. Furthermore, the excitation of waves by core convection is simulated and the results are analyzed regarding their physical plausibility and agreement with observations. These simulations demonstrate that the current set of numerical methods used by the SLH code is promising regarding future, more realistic simulations of astrophysical flows.