Originally Posted by ap72
"ram air" is not a myth, and if applied corrctly will not increase resistance (it can actaully lower it).
However, most people don't know how to design or tune it, all things being equal though ram air is better than cold air.
As an aerospace engineer, I can tell you that airflow management is a complex and difficult activity. You are correct in saying that it is possible to use dynamic pressure from vehicle movement to increase airflow to the engine. You are not correct in saying that it will not increase resistance, however. You will always have less drag by diverting the air around the body than ducting air into the body. Yes, NASA and the Air Force has been looking at and test flying boundary layer control systems for decades, but so far very little practical hardware has come from that. By definition, "ramming" the air into the engine requires you to slow it, which requires drag. Without the resistance, there is no increase in dynamic pressure.