The world's first Expansion/Deflection nozzle hybrid tested

The world's first Expansion/Deflection nozzle hybrid tested
An off angle view of the ED nozzle attached to the combustion chamber of a test hybrid rocket motor, with the central plug / pintle prominent. The rocket motor is being tested by Airborne Engineering and the University of Bristol in the J1 static test firing cell.

(PhysOrg.com) -- Engineers at the University of Bristol and Airborne Engineering last month conducted a number of performance tests of their experimental hybrid rocket engine, called Firecrest.

The Firecrest engine burns high-density polythene fuel with nitrous oxide and can be fitted with either a conventional nozzle or an Expansion/Deflection (ED) nozzle. It will be used in the Canary to investigate the behaviour of ED nozzles when operating at high speed. An ED nozzle is an advanced rocket nozzle, which achieves altitude compensation through interaction of the exhaust gas with the .

All of last month’s seven preliminary tests by engineers at Airborne Engineering and the University of Bristol used a conventional conical nozzle. This month the team test fired an ED nozzle for the first time. Sadly, the experimental graphite nozzle suffered a failure a short time after ignition.

The team is up beat about the failure, which was caused by a combination of heat-induced and pressure-induced stresses in the graphite nozzle.

“We expected some teething-trouble with the ED design,” said James Macfarlane of Airborne Engineering. “It is a tricky shape to make from and the loads are quite high so we knew we might have to make some changes.”

Despite the failure, there are no risks to plans or schedule and a redesign of the nozzle is under way.

Mark Hempsell, Future Programmes Director at Reaction Engines Ltd and Visiting Fellow in at Bristol University, said: “Problems of this sort are to be expected in an experimental programme. It is part of the learning process, which is why we do them.

“Reaction Engines continue to be very excited about the Canary project which will continue to encourage and support the team.”


Explore further

First firing of STERN rocket

Citation: The world's first Expansion/Deflection nozzle hybrid tested (2010, June 8) retrieved 19 September 2019 from https://phys.org/news/2010-06-world-expansiondeflection-nozzle-hybrid.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Jun 08, 2010
Looks like the end of a garden hose attachment.

It is 2010. Man should be riding nuclear torches between planets, not experimenting with disintegrating totem poles (all praises be to Wernher Von Braun).

If nothing else, Single State to Orbit should be the highest priority.

Jun 08, 2010
BTW, it is single "Stage" to orbit, not "State"

Jun 08, 2010
The X33/VentureStar aerospike engine had lots of issue also, due to thermal stresses on the "nozzle". Seems like these attempts to modify the flow of exhaust by putting physical barriers in its way are rather unproductive. After all, the best rocket fuels burn the hottest, and that would be hot enough to melt just about any material we can manufacture. Something like the Shuttle's TPS tiles might withstand the temperatures (maybe), but unfortunately the material required in such nozzle applications also has to be hard (whereas the best thermal innsulators tend to be "fluffy" and brittle.)

Jun 09, 2010
"an advanced rocket nozzle, which achieves altitude compensation through interaction of the exhaust gas with the atmosphere."

Does that make any sense to anyone? I think I do the same thing when I eat beans.

Jun 09, 2010
Does that make any sense to anyone?
Try this:

http://en.wikiped...e_engine

It describes aerospike, which isn't the same design being discussed above. But the concept of altitude compensation through interaction with atmospheric pressure, is quite similar.

Jun 10, 2010
Here's the link...
http://en.wikiped...n_nozzle

I've heard that the X-33 had many problems- the nozzle was the least of which, you might want to check out these for some more info:
http://en.wikiped...tin_X-33

http://www.nasasp...appened/

And: "Why the X-33 VentureStar Gave SSTO a Bad Name" (AIAA 2009-6456).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more