Ah...explanations, explanations...anyway:
Ever heard of inertial systems - how they should be interchangable and to do so you must apply certain new inertail movements/forces to an object when switching (and a physicist babbling about lightspeed and so on started it all with the fact light doesn't behave in that manner).
Long and coplicated story short and simple:
-You speak of a system where the air is stationary and the plane along with the engine moves through it.
-I spoke of a system where the plane and the engine are stationary and the air moves around them.
Both systems are correct and give the same answers.
The reason I used the later system is 'cause it better shows the energetic problem of a subsonic engine.
@aldo - You're copletely missing the point.
The air rushed toward the engine at a supersonic speed (or in the first model, the engine goes in the air at a supersonic speed).
However we can't handle air at those velocities - so in the air intake we force the air to expand inside the engine slowing it down to subsonic speeds.
(...and in the process we introduce a horrendour ammount of drag. In the first system this 'loss' of the air's energy is drag on the whole aircraft from the engine)
The process is far from efficient and we loose energy thanks to the pesky second law of thermodynamics.
@Descenterace
You're right - that's one of the solutions.
However there's a problem: we still have ain't no clue on how air behaves at such speeds.
Therefore the whole engine's desing can be summed with a sinlge word: GUESSWORK.
Is it bad? Yep, it's a massive 2 dimensional desing, a huge box (by using a box, we can simplfy all calculations to a plane, the crossection of the box, and therefore things are esier to calculate) that's darn hard and problematic to integrate into any sensible aircraft.
However the only way to learn what really happens is that: GUESSWORK.
The testflights then either proove or deny the clarification.
So, while current ramjets designs are far from the solution, they're the means to achieve the much needed understanding of supersonic airflow dynamics.
