Fig. 7From: Broadband design of acoustic metasurfaces for the stabilization of a Mach 4 boundary layer flowDimensional growth rates of unstable modes in the BL along different surfaces. The line shapes are used to differentiate the metasurfaces, and the colors are used to differentiate frequencies. (a) the first mode. (b) the second mode of low frequencies. (c) the second mode of high frequenciesBack to article page