This research endeavors to elucidate the understanding of turbulence damping's pivotal role in horizontal slug regime modeling, specifically focusing on twophase water-air flow dynamics. In this paper, it is our aim firstly, to comprehensively explore the conditions under which twophase water-air slug flows manifest, and secondly, to scrutinize the influence of turbulence damping on the formation and characteristics of these slug regimes. Methodologically, this study employs two-dimensional numerical simulations in Ansys Fluent software, utilizing the Reynolds-Averaged Navier-Stokes (RANS) approach for turbulence modeling. The SST k-ω turbulence model & realizable k-ϵ turbulence model are applied to delineate the slug flow area on the flow diagram. Conclusively, the study thoroughly analyzed slug flow parameters and conducted frequency analysis on four instances of slug flow. It highlights the necessity of considering turbulence damping to enhance the reliability of horizontal slug regime modeling in industrial applications. © 2024 IEEE.