I am trying to design a pipe system with a pressure drop of less than 10 bar. The pump output pressure is 110bar, the output pressure is expected to be at least 100bar. However, when I try internal flow simulation and external flow simulation with the same boundary conditions applied, the results are totally different as shown below.
For internal flow simulation, it is shown that the pressure drop is less than 1bar.
(From pump output 110bar to outlet 109.39bar)
I am not sure if it is practical to have less than 1 bar pressure drop over these long pipes. Therefore I try external flow simulation.
For external flow simulation, the pressure drop went crazily down to 0 bar. The pressure drop is 110bar!
I am not sure why are the two simulations with same boundary conditions is different, I dunno which one is correct. Please give advice on how to get the correct pressure drop. Thanks!
Hey,
Just bouncing an idea around for you, I am not 100% sure why it is happening, but externally that just looks to me like you have pressure of 0~1 bar in most of it because that is atmospheric pressure. It has to show it on the scale, I don't think it looks crazy.
Where as your internal simulation while it has an outlet, doesn't have variables determining the pressure etc. if you changed your l/min to atmospheric pressure then the pipe would probably look the same in both simulations. Then you can set surface goals at the outlets and read off the exact pressure there and the volume flow.