Frequency dependency of acoustic black hole effect in cylindrical shells

The acoustic black hole effect has been investigated for cylindrical shells both numerically and analytically, showing the effect to not appear in the low-frequency range. This is in contrast to analyses of simpler geometries like beams, rods and plates, where the effect may be modelled analytically even in the very low-frequency range. The paper presents a first investigation into the underlying phenomena that cause this absence of ABH effect in the low-frequency range for the cylindrical shell, highlighting how coupled wave motion and membrane forces introduced by shell curvature causes the ABH effect to only be obtainable with increasing frequency.