Laboratory and Numerical Modeling of a Lava Flow Analogue: A Comparative Analysis

Volcanic eruptions can bring about lava flows, posing significant hazards and rare direct threats to human life, but they can also cause extensive damage to property and economic activities. Managing volcanic disasters demands swift and accurate information on the behaviour and evolution of lava flows, particularly regarding their extension, displacement, and trajectory. This study addresses numerical and laboratory modelling to understand the dynamics of a lava flow and its frontal advancement. Laboratory experiments of a lava flow analogue, exhibiting a non-Newtonian Herschel–Bulkley fluid behaviour, have been conducted. The fluid parameters at varying temperatures have been determined on the basis of the rheometer and thermal camera measurements. A flow of the Herschel–Bulkley fluid (the lava flow analogue with the fluid parameters determined from the laboratory experiments) is then simulated numerically using the Abaqus software, where a smoothed particle hydrodynamics method has been implemented. A run-out distance, frontal flow displacement, and flow velocity have been determined during laboratory and numerical modelling. When the fluid parameters measured at a constant temperature of 80°C are used, the numerical results diverge from the experimental results over time. To mimic closely the dynamics of the lava flow analogue inferred from the laboratory experiment with its dynamics in the numerical modelling, time-dependent adjustments to the Herschel–Bulkley fluid parameters determined at lower temperatures have been introduced by changing their values during a numerical simulation. This study underscores the importance of constraining parameters of numerical models by the values obtained from laboratory measurements.