Development of Simulation Model for Pyroclastic Flows using COMSOL Multiphysics®

M. Iacuaniello1, A. Montanino1, D. De Gregorio1, G. Zuccaro1
1Università degli Studi di Napoli Federico II, Italy
Published in 2020

The experience of the eruption in Montserrat in 1997 has shown that the resistance of openings of buildings represents a crucial factor in the evaluation of vulnerability to the stresses caused by pyroclastic flows, although the static nature of the building itself is not compromised. The pyroclastic flows are gas-solid mixture which can flow slope down up to reach considerable distances from the point of emission, with a speed that can easily exceed 100km/h (~ 30m/s). The damage caused by the impact on buildings depends on the combination of several factors: the duration of the phenomenon, the temperature of the flow and the pressure produced by the impact. It clearly has emerged the importance of defining a proper numerical model, which fits best the dynamic pressures and temperature ranges associated with a specific scenario at Vesuvius and the Campi Flegrei, defined in the Emergency Plans. This aim is achieved using the multi-physics based finite element method software COMSOL Multiphysics®. In the analysis carried out, variation in various parameters like geometrical characteristics, different materials, input function temperature were studied and are presented in this paper. In addition, fluid-structure analyses were also carried out, considering the flow as incompressible single-phase fluid and applying the Reynolds Averaged Navier-Stokes (RANS) turbulent model. Another main objective, once the vulnerability has been defined, is identifying some ordinary mitigation strategies which also represent a solution of energy saving.