Section: New Software and Platforms

SLOWS

Participants : Luca Arpaia, Andrea Filippini, Maria Kazolea, Mario Ricchiuto [corresponding member] .

SLOWS (“Shallow-water fLOWS”) is a C -platform allowing the simulation of free surface shallow water flows with friction. Arbitrary bathymetries are allowed, defined either by some complex piecewise analytical expression, or by $xyz$ data files, the classical Manning model for friction is used, and an Exner model is implemented for sediment transport. For non-hydrostatic propagation the enhanced Boussinesq equations of Madsen and Sorensen are used. The equations are discretized with a residual based approach which is an adaptation of the schemes developed for aeronautics applications. Due to the inherent unsteadiness of these flows, the time discretization plays an important role. Three different approaches are available, based on conditionally depth-positivity preserving implicit schemes, or on conditionally depth-positivity preserving genuinely explicit discretizations, or on an unconditionally depth-positivity preserving space-time approach. Newton and frozen Newton loops are used to solve the implicit nonlinear equations. The linear algebraic systems arising in the discretization are solved with the MUMPS $$ library. This year implicit and explicit (extrapolated) multistep higher order time integration methods have been implemented, and a mesh adaptation technique based on simple mesh deformation has been also included. The current mid-term objective is to merge SLOWS $$ with the TUCWave code developed by M. Kazolea during her PhD to obtain the first (worldwide) non-hydrostatic dynamically adaptive unstructured mesh Boussinesq code for wave propagation in the near shore region.