Pressure drop prediction in a pipe like structure
 

Hi everyone,

I am having some issues with pressure drop prediction in CFD. The error between CFD and experimental is high, and the higher the cross flow velocities, the higher the error between the two (CFD is over estimating the pressure difference from inlet and outlet).

I am not sure how to proceed from here. My geometry is fairly simple (it is a collection of 13 bundles that are all pipes with no slip wall boundary conditions).

FAQ: http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F

I'm guessing you are using mass flow inlet or some other constant velocity source?
This causes higher pressure drop at the entrance.
You must have an inlet region or define the flow with a developed profile. plot the pressure along a line down the pipe and look at the gradient.