Figure 4
TL predictions of a FMAA composed of two identical and axially spaced HRs. The predictions are either performed by the TMM (a,c) or by the MMT (b,d). In (a,b), the distance between the HRs is \(\delta =5\) cm and the height of the duct, H, varies between 1 and 15 cm. In (c, d), \(\delta \in [5; 37]\) cm, i.e., \(k_0(700 {\mathrm {Hz}})\delta \in [0.2; 1.5]\pi \), and \(H=15\) cm.
