Two turbulence models in SPH: evaluating k-ϵ versus k-ω for dam-break flow simulation

This study presents the implementation and systematic comparison of two widely used two-equation turbulence models, k–ϵ and k–ω, within the Smoothed Particle Hydrodynamics (SPH) framework for dam-break flow simulations. The governing equations are discretized using the mesh-free, fully Lagrangian SPH method, which effectively captures highly transient free-surface phenomena characteristic of dam-break events. Separate subroutines were developed to compute turbulent viscosity for each turbulence model, enabling a detailed and consistent evaluation of their performance under identical flow conditions. Two free-surface flow scenarios were examined, namely dam-break flows over a dry bed and over a wet bed with initially quiescent water. Comparative analysis of velocity fields and flow structures revealed significant differences in turbulence closure behaviour, highlighting the specific strengths and limitations of the k–ϵ and k–ω models in representing turbulent free-surface flows within SPH simulations. The findings provide valuable insights into the selection of suitable turbulence models, enhancing the accuracy and reliability of SPH-based predictions in hydraulic and environmental applications.