[Ames]

Hi,

I am using CFD to compute the pressure and flow in 2D axisymmetric models of blood flow through a stenosis. In several papers I read the terms 'maximum Reynold's number' or 'peak Reynold's number'. In some papers these values are computed at the inlet of the model, while in other papers in the center of the stenosis. I would say that the latter one is better, but I am not sure why one would consider it at the inlet.

I want to use this value of the Reynold's number to determine whether using a laminar model is justified or a transition/turbulence model must be used.

More details on my CFD case: at the inlet a velocity is prescribed and the outlet is stress-free. A no slip condition is applied to wall and the model is rigid.

So my question is: at which location can the peak/maximum Reynold's number best be determined?

Thanks for your help!

[FMDenaro]

Originally Posted by Ames

Hi,

I am using CFD to compute the pressure and flow in 2D axisymmetric models of blood flow through a stenosis. In several papers I read the terms 'maximum Reynold's number' or 'peak Reynold's number'. In some papers these values are computed at the inlet of the model, while in other papers in the center of the stenosis. I would say that the latter one is better, but I am not sure why one would consider it at the inlet.

I want to use this value of the Reynold's number to determine whether using a laminar model is justified or a transition/turbulence model must be used.

More details on my CFD case: at the inlet a velocity is prescribed and the outlet is stress-free. A no slip condition is applied to wall and the model is rigid.

So my question is: at which location can the peak/maximum Reynold's number best be determined?

Thanks for your help!

As you prescribed the velocity at the inlet, you have a known Re number for the inlet condition. In the interior, the local Re number depends on the flow conditions thus you cannot say the peak before having the solution.
Some rude approximation could be obtained in terms of the averaged velocity using the continuity equation as Ainlet*v_av_i= Astenosis*v_av_s. That would allow to evaluate v_av_s

[Ames]

Thanks Filippo, that answers my question!