SSIIM is acronym for Sediment Simulation in Intakes with Multiblock Option. It solves the Navier-Stokes equations using the control volume method with the SIMPLE algorithm and the k-epsilon turbulence model. It also solves the convection-diffusion equation for sediment transport, using Van Rijn's formula for the bed boundary. Also, a water quality module is included. The program is not made for the marine environment, and it can not compute any effects of stratification due to salinity gradients.
The program has an interactive graphical grid editor creating a structured grid. The post-processor includes vector graphics, contour plots, profiles etc. which can run simultaneously with the solver, enabling viewing of intermediate result. A post-processor viewing coloured surfaces in 3D is also made, as a separate program.
There are two versions of the program: SSIIM 1 uses a structured grid and SSIIM 2 uses an unstructured grid. SSIIM 1 is easier to use and the grid is simpler. It is recommended to start with this version. If wetting/drying is to be modelled, it is necessary to use SSIIM 2. Otherwise, SSIIM 1 is recommended. The User's Manual gives more information about the versions.
SSIIM have capability of modelling the sediment transport with moveable bed in complex geometry.It also includes multiple sediment sizes, bed load and suspended load, bed forms etc.
It is developed by Dr. Nils Reider B. Olsen, Professor at NTNU, Norway and complete software is freely available over net with user manual. The program is a stepping stone in the field of Computational Fluid Dynamics (CFD). Many students of Dr. Nils, from all around the world, have used and presently also using this program. In addition of it for many practical problems program have been successfully used. SSIIM is constantly being updated by Dr.Nils.
Many sedimentation problems have been analysed using this software all around the world. Also number of thesis on sedimentation taking the help of this CFD program are also available over net. More can be read over : http://folk.ntnu.no/nilsol/cfd/ Program can be freely downloaded from : http://folk.ntnu.no/nilsol/ssiim/