Fuel is ignited and creates thrust is a fashion similar to that of a turbine engine. (Ramjet/Scramjet...)Scramjet is the name given to a supersonic compression ramjet. It operates in a similar manner to a ramjet, however the air passing through the engine maintains supersonic speed. The scramjet uses hydrogen fuel, just like a rocket engine, but is does not require an onboard supply of oxygen. Instead it uses the oxygen available from the large quantity of air taken in by the engine inlet. This allows a scramjet powered aircraft to fly at hypersonic speeds (above Mach 7) without some of the disadvantages of rocket engines. Because the scramjet does not require a supply of oxygen, many of the problems associated with rocket power are eliminated. Payload can be increased, allowing the aircraft to be much more useful. It can be operated much more economically as well. Scramjets have the potential to be safer than rocket engines. Rockets carry a dangerous mix of explosive hydrogen and fire promoting oxygen, while scramjets carry only hydrogen.There are several barriers to the implementation of scramjet powered aircraft. The amount of testing that can be done in a laboratory is limited. Therefore expensive and time consuming field research is required. Another problem associated with scramjets is the supersonic flow of air around, through and out of the engine. Shock waves are generated by the structure of the engine. Due to the speed of the aircraft and the nature of the shock waves, they tend to pile up in one area. This leads to enormous pressures on the airframe and engine components. The heat resulting from such high speed travel is another problem that must be considered. There have been several tests preformed using scramjet technology. The first of these actual tests was performed by the Defense Advanced Research Projects Agency and Gasl Inc. in New York. They launched a 4-inch diameter miniature scramjet from a g...
