engineer-eer: is your point "PT2" a variation on the 5 measuring points of a gast turbine engine? IIRC, when we solved for various values in ideal engines, P1 = P2 was valid assumption, but doesn't that assume a few things about where one measures P2?
IIRC, IIRC, P1 is "outside" the system and P2 is "at the point of intake" and P3 is compressor discharge pressure P4 combustor out pressure and P5 exhaust pressure (afte it's been through the turbine wheels and made them spin) ... but it's been a few years since my turbojet engine class.
Something about using P2 to substitute for pitot air strikes me as very wrong, but I can't put my finger on it.
*My brain hurts, Mister Gumby!*
