@Retsam n @jousefm… Thank you for all the assistance in finishing my learning project…
I m mechanical engineering final year student and for my final year project i would like study the performance screw turbine for low heads ( 1- 2m) for small canal (used for power generation) using CFD and buliding a small prototype model… I humbly request your assistance 
… Can you give any idea on how to prepare the CAD model for such project
@mnoor_mohamed: I hope you have a lot of time left to study and learn CFD simulations. I’m not an expert in Archimedes screw (pump or generator), but you should become one. SimScale will be willing to help you with simulations setup, however you should be aware that it is YOUR study and YOUR future as a good (or mediocre) engineer. Hence 95% of work is on your shoulders (for good one)…
For CAD model you need to go to modern sources, you may already know:
Archimedes Screw Generator
Screw Hydroturbine
Blades impact on pressure in Screw Turbine
Once technical parameters selected (angle, blades count, length), think to simplify the design (KISS = Keep It Simple, Stupid). For the moment you will use Steady State simulation, so your turbine should operate 100% under the water (you cold not mix air / water, as it implies very resource hungry Transient simulation).
This is enough for the moment: play with it. Do not waste computation resources. Good luck.
Cheers,
Retsam
Thank for all the tips …i will keep in mind… I will start CAD Modeling Have a good weekend