Figure 2
From: Effect of compressibility and non-uniformity in flow on the scattering pattern of acoustic cloak
Total acoustic pressure around acoustic cloak. (a) The acoustic pressure around an existing cloak1 in stationary medium. (b) and (c) The acoustic pressure around convective cloaks7 in moving media with M = 0.1 and M = 0.2, respectively. For all figures, the total acoustic pressure is normalized by incident wave, i.e., \(p^{\prime} \,/\,{p}_{{\rm{i}}{\rm{n}}{\rm{c}}}^{^{\prime} }\), and the incident angles and the Helmholtz numbers are set as α = 0 and kR1 = 3. As shown in (a), the acoustic cloak hides an object in the absence of flow and our numerical simulation shows good accuracy. On the other hand, as shown in (b) and (c), acoustic cloaks in moving media lose their hiding function as the Mach number increases, especially in forward scattering regions.
