Bulk velocity and center line velocity

[goggles31]

When using Bernoulli's equation and calculating Reynold's number which one do we use?

 

[BvU]

You mean for the vevlocity ? Some context, please !

 

[goggles31]

Yes. Do we use the bulk velocity or center line velocity when using Bernoulli's equation and calculating Reynold's number?

 

[BvU]

Bernoulli is for inviscid flow, so I would use the bulk velocity and exercise care when a low Re number comes out that indicates laminar flow !
See the caveat here and keep an eye on the laminar flow result (Poiseuille)