Message-ID: <178@kovacs.UUCP>
Date: Sun, 15-Jul-84 15:26:16 EDT
Article-I.D.: kovacs.178
Posted: Sun Jul 15 15:26:16 1984
Date-Received: Tue, 17-Jul-84 06:27:00 EDT
Organization: Robt Abel & Assoc, Hollywood
Lines: 25



	Regarding Scramjets

          When the airflow  inside  any  airbreathing  engine,  either
        turbine or ramjet, exceeds the speed of sound, the interior of
        the engine become filled with shockwaves produced by  anything
        protuding   into   the  airstream.   This  includes  the  fuel
        injection mechanism.

          When fuel is pumped into a supersonic airstream, it  creates
        another shock wave, trapping the air on one side, and the fuel
	on the other.  Hence, no mixing occurs, and no combustion. The
	internal airflow snuffs it out.

          All  attempts  to  create  a  supersonic  combustion  ramjet
        involve  first  slowing  the  airflow  enough to permit mixing
        (which includes dealing with the airflows mass  and  inertia).
        This  means that the engine must produce enough thrust to move
        the airflow back up to speed, and still move the aircraft.

	  Has anyone considered the old "pulse jet" approach?


					Mike Rivero