SpectraSim Documentation
Parameter · 07 Run Settings

Reference sweep without the mean flow

acoustics.extra_results.no_flow_reference Step 07 · Run Settings

A second sweep of the same model and frequencies without the mean-flow convection, to show what the flow changes in the transmission loss.

Last updated

Theory

Offered only with Mean-flow convection on. The reference sweep drops the convection terms of the system and the Mach numbers of the ports; mesh, medium, perforates and packings are unchanged. The result is the transmission loss with and without the flow and their difference (Additional acoustic results: receivers, section power, dissipation, flow effect).

Equations

ΔTL=TLwith flow−TLwithout flow\Delta TL = TL_{with\ flow} - TL_{without\ flow}
(1)
wheremeaningunit
TLTLTransmission loss of the run's excitation (the average over the inlets when there are several)dB

Default and rule

Default
off
Rule

Off.

Valid range on | off

Cost

One more sweep without convection: about a quarter of the convected sweep on the V4 muffler.