Modern Compressible Flow by John D Anderson
a1 = √(γRT_1 )= √(1.4×287 ×300) = 347.188 m/s
Ms = W/a1
Because at the beginning the air in a constant-area tube was motionless, thus Ms = M = 1.5, W = velocity of the gas ahead of the shock wave, relative to the wave, thus W= velocity of the gas ahead of the shock wave, relative to the tube.
W = Ms • a1 = 1.5 × 347.188 = 520.782 m/s
The necessary value of the wave velocity relative to the tube is 520.782 m/s