Polar gridline transformation method on nearly uniform cell areas and line spacing inside circular geometries

A novel derivation to transfer an actual domain with circular geometries to the computational domain, which is competent for application to computational fluid dynamics, is derived. Outcome formulas could be employed in cases of gridline transformation in the method of linearized, two dimensional fluid transients, as well. In addition, hydraulic parameters can be computed and handled to achieve high precision results, which is called the polar gridline transformation method. This method is used in cases of other kinds of non-prismatic sections or complex shaped domains, such as the turbine spiral case or the specific shape around wicket gates, and the turbine runner. A real example is also illustrated to verify the necessity and validity of the derived formulas, and logical conclusions are included.