Interactions in Stellar Binaries

This dissertation investigates interactions in binary star systems that could impact a wide range of astrophysical phenomena. It first focuses on the common-envelope interaction, where a giant star in a binary system consumes its companion star, causing their separation to rapidly shrink. This process is crucial for forming supernovae, gravitational wave events, and more. The dissertation models this process using rapid population synthesis and 3D hydrodynamical simulations carried out on supercomputers. Finally, the thesis also explores the consumption of planets by their host stars as they evolve into red giants, conducting 3D hydrodynamical simulations to investigate their observational implications.