Modeling Pressurized System with SimHydraulics

I am trying to recreate the plumbing infrastructure of a common residential home. In my simplified model, I am only concerning myself with a single fixture, as model by the Orifice with Variable Area Slot and trying to measure the volumetric flow rate through the fixture and the pressure drop that it creates.

My problem is that the flow sensor is measuring a flow rate when when I expect there to be none and I wish to know if I have connected my model improperly or if using the orifice block was a bad choice.

I have attached a picture of my current model and results.

Answer 1

[Sebastian Castro]

We'd need to know the parameters of the orifice block and the actual displacement you're feeding it via the Signal Builder block. There's definitely a large enough flow area throughout the whole simulation to maintain a flow rate of 23.5 gpm.

... either that, or you made the leakage area really high, which is unlikely :)

- Sebastian

[Frankel Agyei]

Sorry for not included that earlier. I had completely forgot that I gave the orifice block an initial displacement of 0.2 in because I was trying to avoid huge pressure spike that the simulation was creating whenever I closed the orifice.

I did not change the Flow Discharge Coefficient, Crit. Reynolds Number or the Leakage Area value (just the units)

I was interpreting the orifice block to say, based on the current parameters, that there is an initial opening of 0.2 in then at 0.5s a signal is given to the block to increase the block by 0.1 in so that the entire opening in now 0.3 in.

[Sebastian Castro]

Right, so that's why there's still a significant flow rate going through the orifice even when the source is zero... because your initial opening is 0.2.

Does this mean the model makes sense now, or is there still something weird about it?

- Sebastian