May I ask you a question about how to calculate pressure drop in a long tube(acutually there is a big reservior in the middle).

I got some converged results and evaluated pressure drop(P_inlet - P_outlet).

When I calculated each of inlet and outlet pressures, these results are like: Area-Weighted Average

Static Pressure (pascal) -------------------------------- --------------------

outlet_pressure 0

Area-Weighted Average

Static Pressure (pascal) -------------------------------- --------------------

inlet_velocity 386.72406

I think the net prssure(or pressure drop) is ~387 pascal.

However, when I cosidered both of inlet and outlet pressures, the result(net or pressure drop) is different as before.

Area-Weighted Average

Static Pressure (pascal) -------------------------------- --------------------

inlet_velocity 386.72406

outlet_pressure 0

Net 193.36203

Net pressure=193.

Why do these happen? Or net pressure and prssure drop are different?

How can I calculate pressure drop from a point 1 to a point 2 in Fluent?

Thanks for your answer in advance.

the "Net pressure" is just an average (again area-weighted) from all surfaces you have selected.

Bye

George