Coax Pintile Injectors...

I keep seeing this term, Coaxial Pintle Injector
I've only found one picture and it does not exactly jive with the text
descriptions.

Any good pictures/textual descriptions?

wrote:
I keep seeing this term, Coaxial Pintle Injector
I've only found one picture and it does not exactly jive with the text
descriptions.

Any good pictures/textual descriptions?

What you really want are two TRW technical papers on the subject:

AIAA 2000-3871 TRW Pintle Engine Heritage and Performance
Characteristics
AIAA 2000-3853 TRW LCPE 650 Klbf LOX/LH2 Test Results

There's a somewhat useful image at:
http://www.optipoint.com/far/trw2.jpg

Unfortunately, the TRW papers which were on the web before Northrop
Grumman purchased TRW's aerospace group appear to no longer be on
the web. They might be at archive.org but the URLs escape me.
The papers are copyrighted and so I am hesitant to put my copies
up on the net somewhere for general download. I am contacting the
Northrop Grumman division rep for permission.

To do a general technical description...

A pintle engine injector has a post or pintle which comes in
along the axis of the thrust chamber, from the top of the
chamber coming in some distance. Two propellants are injected;
one comes down inside the pintle, which is hollow, and then is
sprayed straight out to the sides by holes drilled in the end
of the pintle. The second is pumped into a manifold or chamber
which is at the base of where the pintle attaches to the top of
the motor chamber. There is a hole slightly larger than the
pintle itself in the manifold; the second propellant is sprayed
down through the gap between the outside of the hole and the
pintle, so it's spraying up along the pintle.

The two sprays meet where the holes are at the end of the pintle.
The result is mixing and a fan of mixed propellant going off
at an intermediate angle.

The image at:
http://www.optipoint.com/far/trw2.jpg
...shows the pintle, the two propellant flows, and the fan
of mixed propellants.

The TRW AIAA papers I referred to above include a lot more detail
on how the geometry works, what's been tested, gotchas, etc.
Hopefully I will have permission to stick them on the web soon.


-george william herbert

George William Herbert wrote:

What you really want are two TRW technical papers on the subject:

AIAA 2000-3871 TRW Pintle Engine Heritage and Performance
Characteristics
AIAA 2000-3853 TRW LCPE 650 Klbf LOX/LH2 Test Results

There's a somewhat useful image at:
http://www.optipoint.com/far/trw2.jpg

Unfortunately, the TRW papers which were on the web before Northrop
Grumman purchased TRW's aerospace group appear to no longer be on
the web. They might be at archive.org but the URLs escape me.

This site
http://www.itam.nsc.ru/users/libr/WIN/98/d7.html
seems to have pdf files of papers that match George's description. The
site might violate copyright, though (I'm suspicious of .ru sites), so
you might do better to go to
http://www.aiaa.org and order them.

--
Geoffrey A. Landis
http://www.sff.net/people/geoffrey.landis