补充：喷管扩张段参数
马赫数    1          1.5        2          2.5      3        3.5        4
面积比    1          1.176  1.688  2.637  4.235  6.790    10.72
压强比    1.893    3.671  7.824  17.09  36.73  76.27    151.8
温度比    1.2        1.45    1.8        2.25    2.8      3.45      4.2