Area Ruling Questions
Okay, for a long time I understood the area-rule concept as basically "where the wings get thicker and bigger, the fuselage gets thinner", eventually as I actually read more about the concept relating to cross-sectional area the concept I used was basically to think of the airplane like a sliced loaf of bread with each section getting progressively bigger until the middle then narrowing back down and the idea of area ruling is to produce a cross-sectional configuration that produces the minimum wave-drag -- thus with the fuselage cross-section thinning down as the wing's cross-section increasing as it's span and thickness increased then decreased, the ideal cross-sectional shape is maintained.
More recently, I read the best explanation yet: As the airflow goes over the wings, like usual, it accelerates over the top; at transonic speeds, the airflow goes supersonic then dams up into a shockwave -- the faster you go, the more area over the top of the wing is supersonic, and the shockwave traverses further and further back; the fuselage is also curved as well and as the airflow goes over convex shaped sections, you get an acceleration over those areas too, and supersonic zones as well with shockwaves terminating at the end of them; being that the thickest point of the fuselage and wings are often right near each other, the fastest airflow over the wing and fuselage effectively amplify the effects of each other producing an unusually powerful shockwave compared to the effects of just one of them by themselves. This explanation seems to explain why the XF-91 Thunderceptor originally was conceptualized with a V-tail -- less interference effects if you only have two airfoils joining the tail rather than three.
Now the questions I have involve the following
1.) The Germans first grasped the concept of Area-Ruling sometime around 1943 by a guy named Otto Frenzl, and by late 1943 wrote a description of this: After the war was over, why did we not end up with this knowledge then? We took all kinds of stuff from the Germans as we progressively occupied them towards the end of the war, and we have it now. The only thing I could think of is if the Russians got it, then after the Cold War we got the information.
2.) If the XF-91 Thunderceptor was originally conceived around a V-tail to avoid transonic interference effects where the tail joined the fuselage, then how is it that it wasn't understood that where the wings of the aircraft joined the fuselage of the aircraft you would get similar results?
3.) How come the F-102 and F-106 required area ruling and the XF-92 did not? The XF-92 had a smaller fineness ratio and thicker wings than the F-102 (all of which to my knowledge aggravate transonic interference effects).
4.) Do air-intakes count as cross-sectional area? Thinking of area ruling like the sliced-loaf of bread it seems to make sense as you get a very low-cross sectional area for the diameter (as there's a hole where the intakes are). I'm not sure where the engines get factored in here, but being that when they're on they produce more thrust than drag, I assume there's no factor; regardless if you think of area ruling not just as cross sectional area but the interference effect of multiple sets of airflows over curved surfaces interacting with each other and amplifying each other's effects, it doesn't seem to be valid (though without a traditional nose the curvature would start at the intake lip and that might yield less fuselage curvature)