PlatinumZealot wrote: ↑
Wed Oct 07, 2020 10:46 pm
@godlameroso The Mercedes compressor outlet has a slanted cut to it and in some models you see a bolted carbonfibre flange with outlet peice on it. Some models you see a metal outlet piece.
Carbon fibre reinforceed plastic is strong.. But heat destabilizes it. The compressor outlet temoerature increase with increased boost pressure. As a pressured pipe the outlet peice would have been tested at at least 150% more pressure than typical operation. It tells me higher temperatures from increased boost was caused the problem.
Yes, he mentioned they test them hydraulically at high pressures. So I think you are right, the issue is probably the temperature. So maybe we can work back from the glass transition temperature of a typical resin, assume that is the compressor outlet temperature and estimate the pressure ratio.
Edit - had a go at it:
Very high Tg prepregs go up to 310°C - the equivalent compressor PR would be in excess of 7!
More standard prepregs have a Tg of ~260°C - the equivalent PR is somewhere around 5.5 (lucky guess godlameroso)
I assumed 300K (27°C) inlet temp and 0.8 compressor efficiency.
Edit 2 - I am being informed it is not unusual to operate above Tg so maybe we can't read too much into it.