Moreover, ifM=l, then M l. This is the case of an infinitely weak normal shock wave. defined as a mach wave 如果M1=1,则M2=1。这种情况对应无限弱的正激波,我们定义 为马赫波。 Furthermore. ifM>l then m<l i e. the mach number behind the normal shock wave is subsonic 如果M1>1,则M2<1:也就是:正激波后的流动是亚彦速的。 As Mi increases above l, the normal shock wave becomes stronger, and m becoming progressively less than 1 当M由逐渐增大时,正激波越来越强,激波后马赫数M越来越 小(在小于1的范围内) However, in the limit as M1oo, M, approaches a finite minimum value,M2→√(-1)2y, which for air is0378 然而,当M1趋于无穷大,M2趋于一有限的最小值M2→√-1)/2y 对于空气其值为0.378。Moreover, if M1=1, then M2=1. This is the case of an infinitely weak normal shock wave, defined as a Mach wave. 如果M1=1，则M2=1。这种情况对应无限弱的正激波，我们定义 为马赫波。 Furthermore, if M1>1, then M2<1; i.e., the Mach number behind the normal shock wave is subsonic. 如果M1>1, 则 M2<1；也就是： 正激波后的流动是亚音速的。 As M1 increases above 1, the normal shock wave becomes stronger, and M2 becoming progressively less than 1. 当 M1 由1逐渐增大时，正激波越来越强，激波后马赫数M2越来越 小（在小于1的范围内）。 However, in the limit as M1→∞,M2 approaches a finite minimum value，M2→ , which for air is 0.378. 然而，当M1趋于无穷大,M2趋于一有限的最小值M2→ ， 对于空气其值为0.378。 ( −1) 2 ( −1) 2