Explore the complexities of modeling the Kelvin-Helmholtz instability in binary neutron star (BNS) mergers in this 37-minute conference talk delivered at the 2023 North American Einstein Toolkit School and Workshop. Gain insights into advanced computational techniques and theoretical frameworks used to simulate these astrophysical phenomena, as presented by an expert from the Center For Computational Relativity and Gravitation. Delve into the challenges and methodologies involved in accurately representing fluid dynamics and gravitational interactions during neutron star coalescence.