As can be seen from Fig. 4, the sound power weighting factor is approximately zero in the plane wave range. This is reasonable since the plane wave in-duct acoustic mode shapes equals unity, i.e., there are no modal cross-terms.
As can be seen from Fig. 4, the sound power weighting factor isapproximately zero in the plane wave range. This is reasonablesince the plane wave in-duct acoustic mode shapes equals unity,i.e., there are no modal cross-terms.