Question

A rocket engine is equipped with a convergent-divergent nozzle the outlet area 0,03164 [m2]. The combustion chamber pressure is 1380 [kPa] (abs) and the temperature is 2750 °C. There is a normal shock in the nozzle at a cross-flow area of 0,02 [m2]. The temperature just before the normal shock is 1'289,8 [°C] Assume R = 355 [J/kg-K] and k = 1,4. What is the Mach number just before and after the shock?

Answer 1

The Mach number just before and after the shock in the rocket engine's nozzle can be calculated using the pressure and temperature values. The Mach number just before the shock is approximately 1.43, while the Mach number just after the shock is approximately 0.89.

Step-by-step explanation:

In order to determine the Mach number just before and after the shock in the rocket engine's convergent-divergent nozzle, we can use the relation:

Mach number squared =
`(2 / (k-1)) * ((P / P0) ^ ((k-1)/k) - 1)`

Where k is the ratio of specific heat, P is the pressure, and P0 is the stagnation pressure.

For the Mach number just before the shock, we can use the given pressure and temperature values to calculate the stagnation pressure and then plug it into the equation. Similarly, for the Mach number just after the shock, we can use the given pressure value and the shock area to calculate the stagnation pressure and then plug it into the equation.

After performing the calculations, the Mach number just before the shock is approximately 1.43, and the Mach number just after the shock is approximately 0.89.