posted on Dec, 21 2014 @ 05:07 PM
a reply to: tinner07
They are similar in that they both lack the compressor stages, shaft, and turbine stages of gas-turbine engine. The main difference would be the speed
of the airflow through the engine. Air in a ramjet is slowed to subsonic speed before combustion, where in a scramjet airflow throughout the engine is
Technical snags include maintaining combustion in a supersonic airflow, cooling issues, and the somewhat limited range of practical applications for
such an engine. Keep in mind with no compressor or turbine, this engine produces 0 thrust at rest, it needs to be traveling at Mach 4-5 before can
even be turned on. NASA has created a working prototype( X-51A Waverider ), but it needed to be ferried up to altitude by a B-52, dropped then
accelerated by a solid rocket booster to Mach 4.8 and ONLY then could the scramjet be engaged.