Date:____________ iii I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. However the algorithm in FLUENT does not seem to be a fully implicit with a little information in its manual.In this thesis, a fully implicit coupled pressure-based solver is developed mainly based on the available literature. The developed code is succesfully tested against some test cases.