Is it required to have node increments in piping according to flow direction?
The node numbering is not related to the flow direction. The flow direction is determined by the flow boundary conditions. However, consistent node numbering may support you when post-processing your results later.
When the compressor type is API 619 Screw Type (Oil Flooded or Dry Run), can we follow the same methodology during the setup of an acoustic model?
You can partly use the same approach. The main difference is that a screw compressor imposes a different source on your piping system, which is typically higher in frequency and less straightforward to determine — it depends on the geometry of the lobes and the opening areas as a function of phase.
There is no dedicated element to model a screw compressor in BOSpulse, but the flow signal from a screw compressor can be imposed using a periodic flow boundary condition. The methodology of the analysis is essentially the same: you try to avoid resonance between your pulsation source and the acoustic modes of the piping system, or between your shaking forces and your structural modes.
What different elements can be modelled in BOSpulse, such as NRVs, dryers, line filters, etc.?
Besides piping elements, you can also model valves, orifices, heat exchangers, and expansion tanks — the latter being particularly important in liquid systems. You may also include structural steel, as will be demonstrated in the third session of this three-part webinar series.
How are compressor element passage sections and compressor valves modelled?
The compressor passage is modelled using equivalent pipes, where acoustic length and volume are the key parameters — this was covered in the first session of this webinar series. The compressor valves are specified per compressor cylinder in the input fields.
Can we export outputs from the tool for use in other domains such as CAE and CFD? Does BOSfluids support DA3 analysis?
You may export results in various output formats. For DA3 analysis, for example, you can export shaking forces to a third-party tool for structural analysis. When using Ansys, you may also use the built-in interface in BOSpulse to complete the analysis entirely within BOSpulse.
Which criteria should we check — API 618 piping or pressure pulsation peak-to-peak (PkPk)?
Both pressure and shaking force criteria are specified, covering pressure pulsations and pressure drop.
Regarding orifice plates with custom openings — compressor vendors often implement them to reduce pulsations in the piping system. How is this measure modelled in BOSpulse? Does it affect both the pulsation analysis and the API 618 check?
Single-hole and multi-hole orifices can be modelled in BOSpulse, and you may specify a custom pressure loss. This can indeed be an effective measure to reduce pulsations.
Is the inclusion of piping supports also possible in the dynamic analysis?
Yes, piping supports can also be modelled, which is important for dynamic stress analysis. We invite you to the third and final session of this webinar series to see how that is done.