Still doing my paperwork….
Just found god way to incorporate the rocket inside of air-scoop. I think it’s correct way
View attachment 113952
NO idea if this was mentioned already - I am just starting with this thread...
Maybe you want to have a look at Hoerner, Fluid Dynamic Drag, Chapter IX, "Drag due to internal flow systems", starting on page 156 in my pdf copy....
Even if the formulas don't make much sense - just reading the text and looking at the figures and tables gets you going quickly!
page 9-4 (as the book is numbered) shows a in-wing radiator installation with a huge area of stalled flow and reverse-flow.... figure 4
page 9-5, figure 5 then shows a radiator installation on a Me-109, with the diffuser shaped like a parabolic curve (...I think it is a parabolic curve...). I remember Paul Lamar doing a lengthy piece on that! ....how to perfect cooling intakes!
[In a different piece he demonstrated images that showed "standing fuel fog clouds" on top of carburator intakes caused by harmonic sound waves - I think it was the 4-rotor LeMans engine - and how that was solved by perfecting the carburator intake bells into a parabolic (...I think!) trumpete shape...]
I remember him explaining HOW you get your parabolic shape according to your radiator face and area.
I think he said he would get the edges down to 2-3mm to the radiator face...Then cut the difuser at the planned cross-section area.
According to his research the flow doesn't separate until nearly at the face of the radiator....and it is safer (against stalls and flow separation) and a LOT SHORTER than the usual 7° diverging difuser....
[Exit is of course a different story - looking at the pictures of the machine at hand - there is not much chance to converge after the radiator according to best practises, but you might be able to do something at the cowling outlet...
Right there with that figure 5, Me109 radiator at 9-5 - it also mentions that it is critical to have a as perfect as possible seal to avoid pressurized cooling air to spill where it is not supposed to - that is a HUGE loss if it occurs.....
I am sure the guys with the experience here will have something to comment on Hoerner and Lamar!
Cheers,
thjakits