IMEX_SfloW2D is a FORTRAN90 code designed to solve an hyperbolic system of partial differential equations with relaxation and source terms.
The model is discretized in time with an explicit-implicit Runge-Kutta method where the hyperbolic part is solved explicetely and the other terms (relaxation and surce) are treated implicitely.
The finite volume solver for the hyperbolic part of the system is based on a semidiscrete central scheme and it is not tied on the specific eigenstructure of the model.
The implicit part is solved with a Newton-Raphson method where the elements of the Jacobian of the nonlinear system are evaluated numerically with a complex step derivative technique.
Version 1.0:

Github project page: http://demichie.github.io/IMEX_SfloW2D/

Authors

Mattia de' Michieli Vitturi (*), Giacomo Lari (**)
(*) Istituto Nazionale di Geofisica e vulcanologia, sezione di Pisa
Via della Faggiola, 36
I-56126 Pisa, Italy
E-mail: matti.nosp@m.a.de.nosp@m.michi.nosp@m.eliv.nosp@m.ittur.nosp@m.i@in.nosp@m.gv.it
(**) Dipartimento di Matematica, Università di Pisa
E-mail: lari@.nosp@m.stud.nosp@m.ent.d.nosp@m.m.un.nosp@m.ipi.i.nosp@m.t