Nikhil Narale
Ansys Employee

Hello, 

The analytical equations make certain assumptions and simplifications, such as ideal flow conditions and neglecting frictional losses. On the other hand, CFD simulations take into account a more comprehensive set of factors, including viscous effects, turbulence, and flow characteristics.

Just for the purpose of validation, you can assume inviscid flow in your CFD simulation, disregarding the realistic nature of the flow (Viscous Model > Inviscid). Then the results may get closer to the analytical results.