General

General

Ho can I model a compressor stage that discharges out into a non-axisymmetric diffuser? A stage interface does not seem appropriate, as averaging would eliminate the non-axisymmetric features in the flow. Is there a way to model a non-axisymmetric frame change interface like this one without resorting to 360-degree model?

    • FAQFAQ
      Participant

      Yes. The approach that is used for these types of cases is called the “Multiple Mixing Plane model” Essentially, the stage interface is subdivided into the minimum number of sectors that are deemed necessary to capture the non-axisymmetry. The upstream compressor stages are replicated accordingly – one for each stage interface sector of the diffuser. The positioning and number of stage interface sectors will depend on the nature of the flow. If the effect of interface position about the machine axis is unclear, it may be necessary to study a couple of different positions for the stage interface splits.