The physics behind a geyser-type eruption: A numerical study

This work develops a thermo-hydrodynamic model and numerical simulations to characterize the eruptive behaviour of fractured low- to medium-enthalpy hydrothermal systems. To treat the multiphase behavior of the system using a simplified but physically coherent approach we use a two phase homogeneous equilibrium model that couples the Navier Stokes and heat transfer equations for saturated water. The properties of the vapour phase are computed in a post-processing step. The results reveal that a hydrothermal eruption develops as an alternating cycle of thermodynamics states that can be physically explained based on Rankine cycle. The analysis of flow patterns and energy highlights that vapour pressure is the core driver of the internal dynamics, acting as the trigger that concentrates high-pressure zones and vertically directed flow. These results may enhance our understanding of the physical processes that govern hydrothermal dynamics in both terrestrial and submarine environments.