Layout of Presentation

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1 Specialized Training Course On Modelling For River Engineering Applications On : SSIIM Program (25th -29th September, 2011), Egypt By : Dr: Ahmed Musa Siyam Eng: Elnazir Saad Ali

2 Layout of Presentation Background SSIIM Versions Motivation and Strength SSIIM Interface Input / Output files Important files Control lfile Koordina file Boogie file Result file

3 BACKGROUND SSIIM is an abbreviation for sediment simulation in intakes with multi-block option. It is developed by Dr. Nils Reider B. Olsen, Professor at Norwegian University of Science and Technology in 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). The program is made for use in hydraulic and sedimentation engineering. It is based on the control volume approach with 3D structured t non-orthogonal grid. The Navier-Stokes equations are solved, and also the convection-diffusion equation for sediment transport.

4 The program has been used in a number of studies relating to the water flow and sediment transport in river and hydropower engineering. This includes trap efficiency of sand traps and hydropower reservoirs, turbidity currents, erosion and local scour, flood waves, head loss and spillways. The program solves the Navier-Stokes2 equations using the control volume method with the SIMPLE algorithm and the k-epsilon turbulence model. It also asosolves the teconvection-diffusion o o equation for sediment transport, using Van Rijn's formula for the bed boundary. Also, a water quality module is included. The Navier-Stokes Equations describe how the velocity, pressure, temperature, t and densityof amoving fluid are related ltd

5 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 structured grid. The postprocessor includes vector graphics, contour plots, profiles etc. which can run simultaneously with the solver, enabling viewing of intermediate result. A postprocessor viewing coloured surfaces in 3D is also made, as a separate program.

6 Lay out of Presentation Background SSIIM Versions Motivation and Strength SSIIM Interface Input / Output files Important files Control file Koordina file Boogie file Result file

7 Ssiim Versions The original version of ssiim program was developed in 1991 using Os/2 operating system. In summer 1997 SSIIM 2.0 was made using unstructured and nested grid both versions of SSIIM were ported to windows. The program has two main versions, the version SSIIM1.0 uses a structured grid while SSIIM 2 uses an unstructured grid. Since then many development has been added. The program pog is a free software and accessed at folk.ntnu.no/nilsol/cfd.

8 Lay out of Presentation Background SSIIM Versions Motivation and Strength SSIIM Interface Input / Output files Important files Control file Koordina file Boogie file Result file

9 Motivation and Strength The main motivation for creating the program was to simulate the sediment movements in general river/channel geometries. This has shown to be difficult to do in physical model studies for fine sediments. Later, the use of the program has been extended to other hydraulic engineering topics, for example spillway modelling, head loss in tunnels, stage-discharge relation-ships in rivers and turbidity currents. The main strength of SSIIIM compared to other CFD program is the capability of modelling sediment transport with movable bed in a complex geometry. This includes multiple sediment sizes, sorting, bed load and suspended load, bed forms and effects of slopping beds. The fine sediments, often under 0.2 mm, are important for wear on turbines. It was also an advantage to be able to simulate other problems as for example sediment filling of reservoirs and channels..

10 Lay out of Presentation Background SSIIM Versions Motivation and Strength SSIIM Interface Input / Output files Important files Control file Koordina file Boogie file Result file

11 User Interface Normally SSIIM run start by reading input files, or generating the grid using the Grid Editor. After generating the grid, the inflow and outflow should be given before the computation are started and the results are viewed. As an input for model four main things are needed as follow: 1.Geometry of the hydraulic structure 2. Water inflow/outflow data 3. sediment data 4. different controlling parameters

12 1. Geometry: The main dt data of the geometry of the hd hydraulic structure t Hydraulic system is modeled by means of x, y and z coordinates with a structured grid(ssiim1). The geometry have six surfaces. The water surface or the roof of the basin define the sixth surface of the three dimensional water body.

13 The Main Interface The windows version consists of only one window with one menu. At start up, the window shows text with information about convergence and the run. The content of the window can be changed by choosing different suboptions in the view option of the menu.

14 Information about convergence

15 Changing the view, will also change the main menu. Example of the different views such as: 1- Map graphics with contour plots or vectors 2- Longitudinal/ cross-sectionalsectional profiles 3- Grid Editor 4- Discharge Editor (SSIIM2)

16 Grid Editor view window

17 2. Water inflow/outflow: The water inflow/outflow have to be specified for all boundaries where water is flowing into or out of the water body. 3. sediment data: Sediment grain size distribution, tion inflow sedinent concentration and fall velocities should be written in the control file.

18 Lay out of Presentation Background SSIIM Versions Motivation and Strength SSIIM Interface Input / Output files Important files Control file Koordina file Boogie file Result file

19 Input/ Output Files Most of the files are only used for special purposes and they are normally not required. Some of the files are output files. The program can produces many of the input files. For simpler cases all the necessary input files can be generated by the program. The two main input files are the control file and the koordina file. All the files are ASCII files, and can be created using a standard editor.

20 4. Input/ Output Files

21 SSIIM files Operations

22 Lay out of Presentation Background SSIIM Versions Motivation and Strength SSIIM Interface Input / Output files Important files Control file Koordina file Boogie file Result file

23 Important Files 1. Control File: control the model and it contain most of the parameters model needs. The main parameters are the size of the array used for the program. Program read each parameter one by one. Different data set contain different parameter. Control File Example:

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25 2. Koordina file Koordina file describes the bed of the geometry with a structured grid (SSIIM 1). The grid can be made using a map, a spread sheet or the grid editor.

26 3. Boogei File boogie is generated which h shows print-out of intermediate results from the calculation. It also shows parameters as average water velocity, shear stress and water depth,trap efficiency and sediment grain size distribution is also written in this file. If any error occur during the run of program, it is written here with explanation before the program terminates. With the help of D and F 1 options in control file additional details can be written in this file. Example:

27 4. Result File

28 Controlling o Parameters a e The program used some letters to indicate some meaning as follows: (1) F : Factors Coefficients (2) W : Wall (3) G : Grid (4) S : Sdi Sediment

29 (1) F : Factors Coefficients letter F use to run sub-programs to initiates calculation of parameters as flow:

30 (2) W : Wall The letter W is use to explain wall and water parameters as follow:

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33 (3) G : Grid

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35 (4) S : Sediment

36 The koordina file

37 The necessary input data is the x, y and z coordinates of the points where the grid lines meet. The format of the data is given below:

38 THANK YOU FOR YOUR ATTENTION