图6. 不同无量纲黏性系数$\omega_0\mu/E$下波速比与(a)驱动波频率和(b)组合无量纲量$\varPi$的关系. 阴影区域为实验观 察到的波速比区域
Fig. 6. The speed ratio in relation to (a) the dimensionless frequency $\omega/\omega_0$ and (b) the dimensionless variable $\varPi$ under different damping coefficients $\omega_0\mu/E$