This question already has an answer here:
Wing mounted jet engines face the free stream at Mach number 1 or above, and they work perfectly for Mach numbers below 1 as well, even though the free stream characteristics change a lot after Mach 1.
- How do the engines manage to work despite the fact that after Mach 1, the Shock waves would try and disrupt the normal airflow?
- If the engines are optimized to work at above Mach 1, does this cause any trouble for them to work under subsonic conditions?
Don't confuse with "Why cant jet engines work with supersonic flow?"