DIY Linear Aerospike Engines
David Nghiem
Hello all, Mr. Lurker here. Out of curiousity, there are MANY rocket engine
builders out there. However, I've so far seen them build only bell nozzle type
engines. How come no one so far is attempting a DIY linear aerospike engine?
Or even a really simplistic design of one. Just curious.
Later
Jonathan A Goff
Umm...Others are more knowledgable about this particular
configuration. However, here is the problem that I see.
Linear aerospikes have very big problems with nonlinearities
at their end. I would suggest trying a normal aerospike or
plug nozzle instead. Those are a lot easier to do (but still
have their problems).
--
Jonathan Goff
"If it should ever come to pass that nothing is worth dying for,
then so shall cease any reason for living." -Thomas J. Clark
tdbear
The X-33 has an aerospike engine based on the J-2 used in the Saturn 1b and
the Saturn V.
In addition, Rocketdyne (I'm not sure if that's still their name) is
building the engine for the VentureStar. That engine is also an aerospike.
I suggest you check out the following sites. If you want I can e-mail the
shortcuts that I use if the following don't work.
Encyclopaedia Astronautica:
http://solar.rtd.utk.edu/~mwade/spaceflt.htm
Look up the J-2 engine under the heading: "Engines"
And VentureStar's homepage:
http://www.venturestar.com
Yours sincerely
Alan Erskine
tdb...@mpx.com.au
David Nghiem wrote in message <7du5dm$aku$1...@news1.bu.edu>...
>
>
>Hello all, Mr. Lurker here. Out of curiousity, there are MANY rocket engine
>builders out there. However, I've so far seen them build only bell nozzle
type
>engines. How come no one so far is attempting a DIY linear aerospike
engine?
>Or even a really simplistic design of one. Just curious.
>
>Later
>
paul.peck
David Nghiem <kl...@bu.edu> wrote in message
news:7du5dm$aku$1...@news1.bu.edu...
>
>
> Hello all, Mr. Lurker here. Out of curiousity, there are MANY rocket
engine
> builders out there. However, I've so far seen them build only bell nozzle
type
> engines. How come no one so far is attempting a DIY linear aerospike
engine?
> Or even a really simplistic design of one. Just curious.
>
> Later
>
It is my understanding that areo-spike engines have been built and tested
only in a lab enviroment. Several months ago, I found an areospike home
page that appologized for being shut down for a time. I hope its still
around. I downloaded a lot of text for my files.
Areospike have a lot of issues that need to be adressed, namely the extra
cooling needed for the ramp and or plug. This is no small task.
Also, as with any rocket engine, one can only build an engine to work within
a limited range of parameters. The the amount of thrust needed by the
engine determines fuel type and consumption rate, and thus, over all rocket
size.
Rocket engines are virtually custom made for a specific rocket (or, a rocket
will be designed to be used with an already exsisting motor, but in general,
rocket engines are not interchangable).
Areospikes have only been tested in a limited capacity. I heard of one plan
to test them on an SR-71 blackbird, but the test I believe, never took
place. I understand that would have been the first actual flight use of an
areospike.
Areospikes were suggested for the space shuttle, but nasa rejected the idea
as the technology was too experimental. In a sence, they were right.
Suppose half way through building the shuttle, they discovered millions of
problems, or aspects of areospikes that rendered them no better than
standard cones ? The whole shuttle project would have been in jeapardy.
Since the shuttle, areospikes have been tested perhaps more than ever
before. The holy grail of rocket science (and Nasa's best wet dream) is a
single stage to orbit veichle. Areospikes promise this capability.
Standard cones are built to operate efficiently only for a limited altitude
range. Thus, several cones or stages need to be used to obtain orbit. The
areospike keeps its efficiency profile throughout its flight.
However, the areospike, like all rocket engines, will have a best efficiency
operation range. If an areospike or a standard cone engine operate below
that efficiency, the rocket will probibally explode or become unstable and
crash. Above the range, and your wasting fuel.
Areospikes may be better (I believe they are), but the raw test data has
never been available for engineers to use in a wide spread manner.
Nasa's X-33 project will undoubtably change this situation. As what has
been discovered becomes dispersed, more knowledge of areospikes, (and
perhaps $ for designs that are no longer "too experimental") becomes
available.
After all, if you had a billion dollar satalite, and could choose to use a
billion dollar rocket with standard cones that you know will work, or spend
a billion dollars to design and areospike rocket that may not work, which
would you choose to best launch your satalite ? (also note, if the
areospike blows up, it will probibally explode in the middle of a stadium
filled with lawyers having a convention, and you will be sued for damages as
well as loosing 2 billion dollars investment).
This is why I believe they havn't been used as often as they could have
been.
Jorge R. Frank
>
> Areospikes were suggested for the space shuttle, but nasa rejected the idea
> as the technology was too experimental. In a sence, they were right.
> Suppose half way through building the shuttle, they discovered millions of
> problems, or aspects of areospikes that rendered them no better than
> standard cones ? The whole shuttle project would have been in jeapardy.
At the time the shuttle was developed, no one had built a reusable
LOX/LH2 engine either. SSME development was plagued by problems, and
delayed STS-1 by a year, at least.
I agree that development of an aerospike engine would also have had
problems, but it doesn't necessarily follow that an aerospike would have
been more troublesome than the SSME we ultimately got, nor that
development problems in the aerospike would have jeopardized the whole
program.
--
JRF
Reply-to address spam-proofed - to reply by E-mail,
check "Organization" and think one step ahead of IBM.
p...@globalreach.net
"paul.peck" <paul...@worldnet.att.net> wrote:
>
> David Nghiem <kl...@bu.edu> wrote in message
> news:7du5dm$aku$1...@news1.bu.edu...
> >
> >
> > Hello all, Mr. Lurker here. Out of curiousity, there are MANY rocket
> engine
> > builders out there. However, I've so far seen them build only bell nozzle
> type
> > engines. How come no one so far is attempting a DIY linear aerospike
> engine?
> > Or even a really simplistic design of one. Just curious.
> >
> > Later
> >
>
> It is my understanding that areo-spike engines have been built and tested
> only in a lab enviroment. Several months ago, I found an areospike home
> page that appologized for being shut down for a time. I hope its still
> around. I downloaded a lot of text for my files.
Well, there were extensive ground tests in the 60's.
> Areospike have a lot of issues that need to be adressed, namely the extra
> cooling needed for the ramp and or plug. This is no small task.
Cooling is hard in ordinary rockets too.
> Also, as with any rocket engine, one can only build an engine to work within
> a limited range of parameters. The the amount of thrust needed by the
> engine determines fuel type and consumption rate, and thus, over all rocket
> size.
>
> Rocket engines are virtually custom made for a specific rocket (or, a rocket
> will be designed to be used with an already exsisting motor, but in general,
> rocket engines are not interchangable).
But the whole point of aerospikes is that they are more efficient over
a wider range of parameters.
> Areospikes have only been tested in a limited capacity. I heard of one plan
> to test them on an SR-71 blackbird, but the test I believe, never took
> place. I understand that would have been the first actual flight use of an
> areospike.
That was LASRE, and it wouldn't have produced really useful data, as the
run time was shorter than the transient phenomenon that might have shown
up.
I am more inclined to believe that the people trying to build LASRE were
simply not extremely good at manufacturing than that aerospikes are a bad
idea.
> Areospikes were suggested for the space shuttle, but nasa rejected the idea
> as the technology was too experimental. In a sence, they were right.
> Suppose half way through building the shuttle, they discovered millions of
> problems, or aspects of areospikes that rendered them no better than
> standard cones ? The whole shuttle project would have been in jeapardy.
Except that, well, they made similar decisions about the shuttle anyway.
They even lost one to SRB burnthrough. They don't appear to have been
afraid of risk.
> Since the shuttle, areospikes have been tested perhaps more than ever
> before. The holy grail of rocket science (and Nasa's best wet dream) is a
> single stage to orbit veichle. Areospikes promise this capability.
Actually, they haven't been tested very much. They *might* be tested
with the X-33 program (and/or Roton, which is testing a different sort of
Aerospike).
Phil
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adrian...@gmail.com
r nozzle) Engine? i'd guess no cause this engine is just a prototype which
was meant for my iron man suit for every altitude flight. the main fuel is
a mixture of hydrogen and oxygen 2:1. the engine harneses the output force
over blades which have a controlable strenght to slow or speed up the rotat
ion letting less or more force out, while controlling the pressure of the o
utput to compensate for the the air pressure for economic flight as the sui
t is small the fuel gets generated from the air depending on the air humidi
ty it will earn more or less fuel, it uses H2O from the air and then it goe
s trough a costom bubbler to convert it from h2o to hho then going through
a filter if needed. in the end it goes into the mixing/activation chamber i
f the gas is not mixed otherwise the gas goes through a one way gas valve t
o not let it backfire causing the reactor to explode or overheat causing th
e loss of fuel and falling to the ground. don't take this seriously as th
is is a prototype.