As for ScramJet engines, they are old and have been around [in testing form] since the 1930s with Germany.
It looks like you want to continue to display your naivete. Fine by me. I think you ought to read and comprehend your own reference material a little better. This "been around since the 30s" quote that you lifted from one of your references was referring to the pulse-jet, not SCramjets. As you are fond of saying "Reading Is Fundamental". If you want to continue to believe SCramjets have been around a long time, go right ahead. You'll just be wrong in your thinking.
The reason pulse jets have been around so long is because their combustion tech is still subsonic. The tough part in combusting supersonically is in sustaining the reaction. Inlet geometries must be very finely tuned in order to create stable shock/expansion patterns under all conditions of airflow angle of attack and angle of sideslip at the inlet entrance. Ask any Aero major who has had to perform "method of characteristics" supersonic flow analysis by hand. It takes a long time, and so only with the advent of supercomputers in the 80s could the computational flowfield analysis be performed quickly enough to support the many design cycles necessary to properly design inlet geometries.
I hear the Aurora uses a 'pulse detonation engine' that generates the infamous 'donuts on a rope'.
I hope you don't think this is the only thing that generates this contrail pattern. Those of us who live in SoCal, south of Vandenburg AFB, are often treated to dusk launches over the Pacific that show the same characteristic in their sunset-illuminated contrails. A very beautiful sight, generated by pulsed rocket engines.
For an exercise in logic, If 'pulse detonation engines' exist in a flying vehicle and they are the next generation engine beyond the scramjet.
Nope. Your logic does not fit the physics. See above discussion of subsonic vs. supersonic combustion.
How could NASA's first public official test be the first live demonstration vehicle?
Technically, it wasn't. The first vehicle experienced a failure of the Orbital Sciences booster package back in 2002. That vehicle never reached the test point at which the SCramjet would be lit and the vehicle separate from the booster. So this test of a few weeks ago was the 2nd attempt, 1st success.
'Hypersonic' and 'ScramJet' are commonly used to describe a variety of 'platforms'
Maybe in amateur circles, but not by professionals! Again, it is obvious you have never studied as an Aero engineer, nor made this your profession. Professionals do not throw terms around like these interchangeably, especially when neither of these describe "platforms" and both describe different things. "Hypersonic" is a flight regieme, not a platform. It's how fast you go (> Mach 5), not how you achieve it. "SCramjet" is a form of propulsion technology that can take you to the hypersonic regieme. If you'd like to learn about how the linear assumptions of supersonic flow theory break down and become highly non-linear in the hypersonic regieme, I can give you references. One of the best textbooks is "Modern Compressible Flow, With Historical Perspective" by Anderson (1982 - ISBN 0-07-001654-2).
Class dismissed! (Yes, I do teach Aero, including supersonic wind tunnel labs).
RainmanTime
