180 dB — that’s a lot of vibration. I didn’t know it was that high, but it’s not surprising at the front of those compressors, the shock waves at the inlet, and the air deceleration and compression.
200 lbm/sec, 1,000° C to -150° C in 10 milliseconds, 180 dB. Hard to believe all the tubes in that heat exchanger lasting under that vibration load and remaining leak free. Hydrogen leaks in the HX would not be good.
My Dad built satellites at GE and took me in to witness a shake table test simulating rocket lift off. It was the most incredible thing to see.
Yes it is. I can’t remember the numbers, but I think a jet engine is around 120 decibels and the sound pressure doubles every 10 decibels. That’s the way I remember picturing what is actually happening.
After reading everything again, I have come to the conclusion that the inlet is blocked off entirely before it ever gets into the transition phase, the precooler would otherwise be destroyed.