These graphs do vary a lot as, like you said, it is very dependant on the airframe geometry. Yes Cd is not the drag force, but Cd is better for comparisons, modeling and analysis as it is dimensionless.

Also on your graph, I'm guessing that is just the Cd for the wing, what about the fuselage, tail, external stores and any other bits that stick out of the aircraft? Wouldn't the Typhoon have a lower Cd than that of the F-15 due to the delta wing configuration?

Also if the F-15 could push M1.2 max then my guess is its speed would be varying, would it not be constantly approaching the mach 1 barrier resulting in very high drag?

(Btw these aren't rhetorical questions, they are genuine questions for people to answer)

(2) Once you are past that spike, even if Cd decreases with speed, Drag will increase with speed. This is because the Cd is not going to increase or decrease exponentially, whereas Velocity^2 will always increase exponentially. In fact most of the time Cd increases or decreases are very marginal and gentle past the sonic spike (or before it).

(3) Delta wing or not, what really matters when it comes to the wing's plan form is the leading edge sweep and the distance the wing is from the nose. I do not see a huge difference here. Nor should there be given that F-15 is an airframe that can reach Mach 2.5 on reheat so it cannot be very draggy at supersonic speeds. The whole supercruise thing is not likely to be an issue with the dynamic thrust of the engines at maximum millitary thrust and at the speeds concerned.

But with a delta wing there is a larger sweep angle. Comparing the drawing of the Typhoon with that of the F-15 you can see by eye that there is a difference. The larger the sweep angle in super-sonic flight, the faster you can go before the mach cone meets your leading edges. This is one of the main advantages of using a delta wing. The F-15 is a very aerodynamically efficient airframe, and its excellent thrust allows it to overcome the drag force as those high speeds, but I'd say the Cd(total) of the Tiffy is lower than that of the F-15.

Another thing, those comparison drawings you did where you compared two halves of two different aircraft were really good. Did you do one for the Tiffy and F-15?

LmRaptor, wing REFERENCE area (50 m^2) includes all area (including fuselage) within the wing leading edge and trailing edge extended to the airplane centerline. Your measured "wing only" area sounds about right. That is why comparing wing reference area of two different airplanes is meaningless. For that matter, comparing ANY aero coefficient between two different airplanes is equally meaningless. Go ahead and compare drag, but not drag coefficient, for example.

That delta wing, tucked back out of the mach cone is fine for cruise, but maneuvering is another story. Deltas generally have a poorer L/D slope as AoA increases. So relative to cruise drag, the delta will have higher drag at maneuvering AoA than a wing with less sweep. That hurts sustained g performance, but not instantaneous g.

As far as comparing coefficients between two different airplanes, when did you ever see two airplanes with the same reference area? Or the same reference length? Never! So you simply cannot compare coefficients with any meaningful results. If you are talking about advanced design studies of hypothetical airplanes, you are right. I am speaking of real airplanes, in service today.

We agree on the delta maneuverability question. I should have said at higher AoA (read low-medium airspeed) sustained g capability suffers, which is not the same as "maneuverability" to use your word. You may point the Tiffy very quickly on the first turn (canards!), but at the sacrifice of considerable speed, so you'd best make that first shot count. Yes, at high speed (low AoA) it really performs, no question. And two very powerful engines help overcome the sustained g problem. But the fact remains that a delta is not as good as a wing with less sweep at lower speed sustained g. That is why the only deltas in USAF were interceptors (F-102, F-106) and a bomber (B-5.

I don't think it is really so much a "delta" characteristic, but rather a characteristic of a wide-chord, short-span, wing compared to a narrower-chord, long-span, wing.

No, it's the shape. CL vs. CD for a true "delta" wing is going to look good for low values of CL, but terrible for high values. Or in other words, CD will be good for low CL and bad for high CL. Change the shape of the wing to something where the wing tips are not points of a triangle and you'll get different behavior. Some delta wing shapes wouldn't make sense of course. You wouldn't, for example, make a delta wing with a 45 degree sweep. But if you did, it would still be pretty bad at high AoA I think. Hehehe.