Aerospike
John Parker Woods
an atvantage is such an engine. Does anyone have data that compares the
performance under actual conditions.
I would think that if it was that good, that boeing would be refitting their
expendable booster with aerospike engines. Or at least, testing it on a small
sounding rocket.
John Woods
jwo...@seanet.com
Damon Hill
A linear aerospike engine is part of the X-33's design, and will be part of
the Venture Star if it is built.
There is/was a web page about the aerospike engine, but my bookmark no longer
seems valid. Does anyone have the current URL?
--Damon
Motie 52
In article <6ubmbu$h...@enews4.newsguy.com>, da...@halcyon.com (Damon Hill)
writes:
>There is/was a web page about the aerospike engine, but my bookmark no longer
>seems valid. Does anyone have the current URL?
http://www.boeing.com/space/rdyne/x33/aerospik/aerospik.htm
Pretty good site for laymen like myself, although there may be others with more
engineering data.
The Mote
"Men who have worked together to reach the stars are not likely to descend
together into the depths of war and desolation" - LBJ (1958)
Tom
the moderator with one of my replies. I didn't know he was the
moderator so I wound up ticking him off more. [I promise to
behave]).
There is a good treatise on the Aerospike engine in the book
"Frontiers of Space" by Bono & Gatland (whom I believe are
holders of the Patent on the Aerospike).
I've done some analysis on these. The "Exit Plane" appears
to be a frustum whose large top diam is at the outer exit
plane diameter. The small bottom diam is the point where
the spike turns into a plug.
So for a given diameter, an aerospike has a larger exit
area than a same-diameter bell engine.
Another advantage is that the effective exit area goes down
as air pressure goes up. This means that on the ground it
behaves as a sea-level engine and at altitude as a full
vacuum engine.
Third advantage is that a circular aerospike can attach
directly to the base of the tankage with a MUCH lighter
engine mount.
Fourth advantage is that the flat base of a truncated
aerospike (Plug Nozzle) engine can double as a heat
shield with an LH2 flow of about 1/43rd of liftoff flow.
Result is a fully recoverable Bus Module with a mass
fraction of about 0.925
Damon Hill
>
>In article <6ubmbu$h...@enews4.newsguy.com>, da...@halcyon.com (Damon Hill)
>writes:
>
>>There is/was a web page about the aerospike engine, but my bookmark no longer
>>seems valid. Does anyone have the current URL?
>
>http://www.boeing.com/space/rdyne/x33/aerospik/aerospik.htm
>
>Pretty good site for laymen like myself, although there may be others with more
>engineering data.
That wasn't the one I was thinking of, though it's a good source. Here's the
site maintained by Ken Davidian:
http://paris.lerc.nasa.gov/AEROSPIKE/
--Damon
I. Stirling
> I've heard lot's about the aerospike engine, but never solid data. How much of
> an atvantage is such an engine. Does anyone have data that compares the
> performance under actual conditions.
In my limited knowledge, Aerospikes are ideal for SSTO, as the thing
can relatively easily auto-vary the expansion ratio for good performance
all the way from sea level to vacuum, whild being much lighter than a
similar bell nozzle.
The advantage on multi-stage rockets, that don't need to work in a wide
variety of air pressures is smaller.
And, as the advantage is smaller, but it's not proven technology, it may
not be worthwhile, in the manufacturers opinions.
Tom
and look for:
ROMBUS, Ithacus, Pegasus, SASSTO, Plug-nozzle, Philip Bono,
Kenneth Gatland (they hold the Aerospike patent), and look
up the book "Frontiers of Space" by Bono/Gatland.
Also, there was an article in a 60's or 70's "Journal of
Spacecraft and Rockets".
ROMBUS - Reusable Orbital Module Booster and Utility Shuttle.
ITHACUS - Intercontinental Ballistic Troop Transport.
PEGASUS - Intercontinental Ballistic Passenger Transport.