Bypass-Mounted Air-Cooled Air-Coolers

[KJ_Lesnick]

This is something that pertains to the J-58 used on the Lockheed A-12's and so forth.  I remember something on a forum about the aircraft having "bypass mounted air-cooled air-coolers".  What is that?

[Hobbes]

I expect that would be to cool the compressed air before it enters the combustion area (like an intercooler on a piston engine).
The heat exchanger moves the heat to the bypass ducting and releases it there in the uncompressed (and therefore cooler) bypass air.

[KJ_Lesnick]

I expect that would be to cool the compressed air before it enters the combustion area (like an intercooler on a piston engine).

I've never heard anything to suggest an intercooler on the J-58, though I could be wrong.  It would explain somethings though (it would allow the compressor to run at higher temperatures)