ORIGINAL: JohnMac
Lt Dan,
Well it has already been done. I talked to the boys fromJetworld in Germany when the visisted the JMA AGM in the UK a couple of years ago, and they showed me a prototype system. They then published details in the German Jetpower magazine.
A pressure regulation system would be required but a simple mechanical device could be used. Getting one small a light enough might be the problem. Pressure loss has already been dealt with, it's insignificant; but the point you make about temparature rise may provide a difficulty. When you compress air it gets hot, but is air bled from our compressors hot enough to cause a problem?
The lack of a commercailly available system has prevented me from going any further with this idea.
Regards,
John.
I never said it was impossible, just complex!
The bleed temp depends on where you bleed it from, of course, our engines are single stage compressors so you don't really have much choice. On the big jets, bleed air is taken from several different compressor stages at different temperatures. It passes through a regulating valve and then through a precooler (heat exchanger) where the heat is exchanged through cold ram air from the fan section (another valve), before it is passed on into the aircraft for use. I would love to have onboard electrical generation and bleed air, but it becomes a big departure from the KISS concept that I love!