SPHERA simulates three dam break scenarios for the highest Italian dam among those in operation (Alpe Gera). The first scenario considers an instantaneous dam break. The second scenario introduces a flood control dam designed by increasing the crest elevation of the lower Campo Moro dam. The third scenario considers a simultaneous double dam break of both Alpe Gera and Campo Moro dams. The nonstationary 3D fluid dynamic fields are analyzed, from which we also derive 2D synthetic fields of maximum water head and maximum specific flow rate, which are useful for flood risk analyses. The input files are already available on SPHERA’s public repository on github.com.

SPHERA has been enhanced to deal with ‘fluid – moving solid structure’ interactions under no-slip conditions (including in 3D laminar motion regimes). The code is validated on a uniform sliding bearing (uniform oil film thickness) and a linear sliding bearing (linear oil film thickness in x), which is also used for a 3D complex surface demonstration test. The validations refer to comparisons with analytical solutions, generalized here for any Dirichlet boundary condition. An initial validation of the code on ‘fluid-fixed boundary’ interactions in laminar regime is also reported. From a comparison with the state of the art (i.e., 2D codes based on the simplified Reynolds’ equation for fluid films), SPHERA adopts a complete 3D formulation of the Navier-Stokes equations for incompressible fluids of uniform viscosity, also validated on local quantities (pressure and velocity profiles), and simulates complex 3D surfaces.