subsonic range

In the whole flow range, the impeller operates under subsonic condition and the radial diffuser operates under transonic condition, thus the choked mass flow rate is determined by the throat area of the radial diffuser.

整个特性线范围内离心叶轮基本在亚音速情况下工作，而径向扩压器是在跨音速条件下工作，离心压气机整机的最大流量是由径向扩压器的喉部面积决定的；

No matter the boundary layer is subsonic or supersonic, nonparallel effects are obvious at the critical Reynolds number, such that the critical Reynolds number is reduced and the frequency range of unstable disturbances is broadened at the critical Reynolds number.

无论是在亚音速还是超音速边界层中，非平行性的影响在临界雷诺数处比较明显，具体是一使得临界雷诺数变小，二使得临界雷诺数处增长扰动的频率范围变得更大。