the correct mesh image

Hi 

Sorry but does it mean that inviscid solver will not give a parabolic profile at outlet if inlet velocity profile is parabolic as well. 

For inviscid flow, if uniform velocity is imposed at inlet and then outlet should be a uniform velocity only as per physics of flow

Dear Abdul, 

Thanks for your comment. 

Imagine a simple flow in a duct with no viscosity, there will be no development of boundary layer and the flow will remain uniform at the outlet if uniform velocity was imposed at inlet. 

Similarly if I give a parabolic profile at inlet, I must get a parabolic profile at outlet. 

There are two conditions when one can assume inviscid flow conditions 

1) Very high Reynolds number where diffusion term is negligible 

2) The fluid has no viscosity ( Theoretical case). 

I was trying to see if I  can get a parabolic profile at outlet for viscous and inviscid flow if inlet is parabolic. 

For laminar viscous flow, results are satisfactory but for inviscid flow the outlet profile is anything but not parabolic. Also convergence in dilation is fluctuation from 1e-6 to 1e01 which is not understandable 

Hello Shashank,

can you let me know in details which  boundary conditions you have imposed to your computational domain?

Thank you,

Maurizio

Dear Shashank ,

I agree with Professor Aziz , the entrance can disturb the flow and you should increase the length of the duct in order get established flow .

Djelloul .

Helo,

For the inviscid flow in a duct with a parabolic velocity profile, please check the following points, some of which can be used as boundary conditions and some can be used assess the CFD model used:

1- The mesh should be more or less uniform in all directions

2- flow should be assumed steady, incompressible

3- the static pressure is uniform

4- the total pressure varies like the square of the flow velocity

5- both static and total pressure are constant along the duct.

Good luck,

Wahid

I agree with Dr. Zaafar regarding the simulation.Although in-viscid flow is simulated with parabolic flow at inlet, the velocity gradient normal to walls would reduce the peak at center and increase the near wall velocities leading to little shorter and wider profile at outlet. This occurs as shear stress exist due to velocity gradient which transfers momentum across the layers.

 So i suspect something wrong in modelling itself. Domain is 2D symmetric however Outlet shows unsymmetrical flow conditions?, Please provide domain outline with boundary condition with values used for resolving the errors.