Mach number change across the normal shock

Mach number change across the normal shock Mach number change across the normal shock

Multiplying the above pressure (or density) ratio equations together gives the Mach number relationship directly:

2_ Ml + 5_

Подпись:

Подпись: For air Подпись: For Mi —► oo Mi —► ^ For M —► 1 Mi —> 1 Подпись: (l//7 = 0.378 for air)

Inspection of these last equations shows that Mi has upper and lower limiting values:

Thus the exit Mach number from a normal shock wave is always subsonic and for air has values between 1 and 0.378.