Representing an orifice whose length is greater than the orifice diamter using Simscape Fluids (IL)

How can I represent a nozzle using the Simscape Fluids Library?

I am trying to recreate a hydraulics model that was made using different softwares (GT-SUITE, SimulationX), in the model there are orifices with lengths that are equal to or larger than the diameter of the orifice. To represent such a nozzle in Simscape should I set it up as a narrow pipe? or is there another object that I can use.

Answer 1

[Chuguang Pan]

I think you can realize such a nozzle using both Pipe (IL) block and Orifice (IL) block. For example, you can connect orifice block at the end of a segment narrow pipe to simulate a nozzle with length larger than the diameter of orifice.

[ty]

Hi Chuguang,

Thank you for the suggestion, I still need to compare with the results from the other softwares, but this makes sense to me.

Answer 2

[Yifeng Tang]

Hi @ty,

I agree with what @Chuguang Pan has discussed: the Pipe (IL) block and the Orifice (IL) block can be useful here.

Another thing to consider: how do the other software (GT, SimulationX) use the orifice length parameter? Which equations does it appear in? Does it contribute to the "volume" of an orifice or it adjust the pressure drop characteristics of the orifice? You may need to read their documentation to understand this. Once you have such information, you can look into whether it's possible to incorporate such effects in Simscape. You may need to (1) adjust parameters in Simscape to mimic the behavior, or (2) add volume block (chamber, pipe) if length does contribute to an orifice volume, or (3) write your own Simscape component to include the extra equations.

Whichever path you take or try, it's a good idea to set up test harness models to understand how pressure-flow characteristics are affected by this length parameter, in both Simscape and a different software.

Hope this helps.