New Jet Engine Tested

SpaceAdmiral writes "A revolutionary new jet engine has recently been tested in Australia. It is hoped that the engine, designed by UK defense firm QinetiQ and capable of Mach 7.6, will pave the way for ultra fast, intercontinental air travel. Scramjet (supersonic combustion ramjet) engines have no moving parts and take all of the oxygen they need (to burn hydrogen fuel) from the air, allowing for larger loads than rockets which must carry oxygen for fuel."

Comments

Queensland Univ is running the HyShot program

[xmas2003]

Here's the main page about the University of Queensland (Australia) Centre for Hypersonics program that is running this program. The BBC article mentioned is pulled from their press release.

First application for Mach 7+ won't be passenger travel, but military (if not already used) where it will not only be fast, but louder than heck - after all Jet Noise is the Sound of Freedom! ;-)

Re:ALL of the oxygen?

[Napoleon The Pig]

I'm not even sure where to start with this one...

1. Turbines in a jet engine are located after compression and combustion occur. Compression is due to compressors located after the inlet of the engine and before the combustion chamber where fuel is introduced and ignited. From the combustion chamber the high pressure, high temperature exhaust is then fed through the turbines which then generate power for quite a few different things including running the compressors.

Engine Theroy: Suck, Squeeze, Bang, Blow.

2. Jet engines do not work at very high speed not because of stresses in the compressors/turbines but rather because of the problems with supersonic flow. For supersonic aircraft the airflow into the engine is slowed to subsonic speeds using inlet geometry to control the oblique and normal shocks in the flow. Yes, theoretically you could spin the compressor faster than it's mechanical stress limits but that would occur a lot longer after the engine stopped working due to the flow.

3. The reason hydrogen is used as fuel for the scramjet is because the pressure tolerances for the engine are extremely small. The compressed flow must maintain supersonic speed, contain enough heat to ignite the fuel, and have enough time to have initiation and reaction occur inside the combustion chamber before it's ejected out the exhaust nozzle.

The reason they're comparing a Scramjet to a rocket engine is because having a Scramjet would dramatically reduce the weight of orbital flight by not having to carry its own oxidizer. For example: 75% of the weight of the Space Shuttle during launch is stored in LOX used as fuel.

However the feasibility of using a Scramjet engine for a single stage to orbit vehicle poses problems of its own. Way too many to list here. But solutions might be found to these problems as technology increases.