Section: New Software and Platforms

SLOWS

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

SLOWS is a C-platform allowing the simulation of free surface shallow water flows with friction. It can be used to simulate near shore hydrodynamics, wave transformations processes, etc. Both hydrostatic (shallow water) and non-hydrostatic (Boussinesq-type) versions exist. The latter are currently based on the dispersive model of Madsen and Sorensen (1992). A fully nonlinear (Green-Naghdi) version is under development based on the one dimensional prototype discussed in [99] . 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 mesh deformation ($r$-adaptation) has been also included. A node-centred high order MUSCL finite volume discretisation has also been added to benchmark the mesh adaptation strategies, and compare with the residual based method constituting the kernel of the code. To date, SLOWS is the only existing near shore code allowing to choose between a classical finite volume approximation, and the more recent non-linear residual distribution methods developed in CARDAMOM. It allows an accurate simulation of free surface flows on arbitrary topographies with both static and time dependent unstructured mesh adaptation, accounting for both hydrostatic and non-hydrostatic effects.