Elliptical CC

GRIM · Post by **GRIM** » Thu Feb 21, 2008 3:01 am

Heres a better Vid of the small semi oval engine , now with an Augmentor on the inlet.

http://www.youtube.com/watch?v=wadzE_AqN70

Still starts with no compressed air, still got the wicked orange flame from the exhaust , just cant see it very well in the day

See how as the fuel pressure increases the whole rig slides back on the angle “rails” crude but works, indicates about 1 ½ kg , That’s 3.3 lbs in old money , gas pressure gets up to about 110psi btw Sure blows loads of air out of that Augmentor , but I think I made it too big ,

The combustion chamber is another story , dead cold at the back and “well” hot to say the least in the combustion zone,

All good fun, and I am quite pleased with it , but I am sure there is lot that could be improved,

This vid shows startup thru flameout ,

http://www.youtube.com/watch?v=heLOHoKL4U4

It takes approx ½ kg to get this rather heavy and crude thrust rig to move , I have not added this to any readings , and the copper tube spring balance was calibrated against a known to be good scale,

Sounds like its going to flame out at about 1/2kg then comes “on cam” and runs right up to 1 1/2kg n a bit before flameout,

All in all something a little different and good fun .

GRIM · Post by **GRIM** » Thu Feb 21, 2008 3:53 pm

Big Bro is is up next , the locky will have to wait till i got enough compressed air

The night photo was big bro last night at 23:00 hrs, plenty of gas coming out the inlet to burn in the Augmentor tonight

GRIM · Post by **GRIM** » Sun Feb 24, 2008 2:38 am

Here is a vid of the larger version of the semi elliptical cc deal ,

http://www.youtube.com/watch?v=XfdX6s62nh4

Also some photos and the latest drawings if anybody's interested

Still no reliable thrust readings , the first attempt I melted the scale ,
The second attempt filled the scale up with sand ,

But not more than about 12 lbs thrust as far as I could make out ,
I think I need a bigger cone on the exhaust or something,

Sure gets HOT and ear protection is becoming essential , I am using those little orange sponge things and its hurting now even with them ,got to get some proper ear defenders .

Could use some feedback guys ,

If I am Boring you, please say so , if you think I am wasting my time because xxxxx please say so,

I feel that I have taken these two engines as far as my limited knowledge will allow ,

I feel sure there is more to be had from the tailpipes but I lack the knowledge to design something better ,
I see the heat patterns on the cc , they should be telling me something ,
I lack the experience to draw a conclusion,
Anyone care to comment ?

BUT I AM STILL HAVING FUN

PyroJoe · Post by **PyroJoe** » Sun Feb 24, 2008 3:38 am

Melted the scale, that's a kick.
They look awesome, I like the dark menacing look with the shiny chrome style augmentors.
Those orange earplugs suck. I had a big draft engine shotgun today and my right ear started ringing with the orange plugs in.

The intake looks like it may be pulling a fair amount of hot air above that exhaust pipe. You may get better thrust by adjusting the intake to pull in cooler air. Just from the looks the tail pipe may also have a cool spot from the intake, if this is so, you may be losing some heat that needs to travel back to the expansion section of the tail. Not sure if that will help, but your way ahead of me in thrust. Your pulling 12 pounds, so far my best draft engine is pulling 6 oz.

Keep up the good work, and keep trying new things. Two blistered thumbs up.

GRIM · Post by **GRIM** » Mon Feb 25, 2008 2:34 am

Thanks for the reply Joe, both good obs , maybe an insulator plate to help minimize the heat transfer , both ways ,

Tried this , just for shits n grims,
As usual mike was right , the sucker would only run at low throttle,

Obviously this changed the tuned length , so i tried shorter and longer tailpipes to compensate , no joy , so i welded the corner back on and its back to screeechville

Still open to suggestions as to where to go from here

Irvine.J · Post by **Irvine.J** » Mon Feb 25, 2008 12:04 pm

Hiya grim,
Long time no post, I been hell busy.
So here goes, a quick note.

Mate she is a beauty.
One of the most obvious (which you yourself noticed) things about this engine is its absolutely massive amount of heat. All of that is just asking to be used to drive mass flow. The engine itslef might also be a fraction short, but I'd say your intake looks ok. These are just observations from not knowing any dims. Its very interesting indeed. I'd say that augmenter design would be a little more effective in a classic design, but thats just me.

Whats the length of this engine, it looks quite short for 12 lbs, so I really think your little tricks here are doing you quite well.

Keep up the good work, try a few augmenters, I think your doing good work.

Are you going to try a classical augmenter on your Oval CC engine? Flat on the short side, bulgeing out around the intakes, that would be sweet too!

GRIM · Post by **GRIM** » Mon Feb 25, 2008 12:35 pm

Hey james , thanks for the feedback ,
the dimensions are in two pdf files in the post above , would be really great if someone could at least suggest , based on their experience where to lengthen the tail , in the straight section , the cone , bigger cone ?

so many variables , i have some ideas , but not much time ,
yes i am considering something for the flat oval motor probably in thin tin plate , run out of stainless now

keep the ideas coming , one tends to get tunnel vision working alone , outside opinions, criticisms , help a lot

hows the hand doing ??

thanks again

Irvine.J · Post by **Irvine.J** » Mon Feb 25, 2008 1:09 pm

Going well thanks mate, can nearly get to a fist but not quite yet, long way to go, thanks for asking though.

Upon further inspection i would say your straight section could be a little shorter...but thats all for now....keep up what your doing, love it.

Jim Berquist · Post by **Jim Berquist** » Tue Feb 26, 2008 2:12 am

Try this! If it works I get half!

Eric gets the other half as he inspired the Idea!

That leaves you with 1/2 of my 1/2 and what ever Eric offers you.

Yep Ram Jet! Augmentation!!

In this configuration, it could be called after burner.

It is a RAM JET! .

It should provide enough oomph to make it fast.

Sonic pressures provided by the P,J. drive it. .

Entrained fresh air feed it . It will produce more Trust then not. My guese is it would provide SUB SONIC performance, Yet enough to wake up the dead!

GRIM · Post by **GRIM** » Tue Feb 26, 2008 2:19 am

Thanks for the reply james

Tried this today on the small engine , wedged the front lip of the augmentor under the edge of the intake flare, so the inlet is almost inside the augmentor ,

Now strange things happen ,

Starts and revs up easier !!

makes less power only about 2,5 lbs because it flames out earlier

Tried with no augmentor , makes about 2 lbs flames out

This calls attention to two points

point 1,
(I think ) that the inlet augmentor really only makes any significant thrust when there is EXCESS gas being blown out of the inlet , in the higher gas flow/ power situation,
I believe it is being effectively burned and turned into thrust, that may be good for some existing engines

Point 2,
Is that i may have designed such a crappy combustion chamber and or tailpipe that i am trying to reverse engineer the result to fix the problem,

Enough for today , the quest will continue

Jim Berquist · Post by **Jim Berquist** » Tue Feb 26, 2008 2:26 am

Man that puppy get hot!

GRIM · Post by **GRIM** » Tue Feb 26, 2008 2:37 am

Jim
Holy Shit , that looks like an afterburner , or is it a beforeburner or intercoolerburner WOW

, i am tired , boy gona dream some weird stuff tonight , and think on that one tomorrow

thanks anyway

"you can check out any time you like, but you can never leeeave "

GRIM · Post by **GRIM** » Tue Feb 26, 2008 1:34 pm

Hey jim , i was tired last night , did not see the ramjet title and a really interesting idea it is , gona give that some thought and ask eric some questions ,

The ironic thing is that in your edit you mentioned waking the dead ,

Well in one of the last videos on you tube where its blowing all the dust away thats my little test site outside of an out of town cemetery,
None of the inmates have complained YET , BUT WITH THE RAMJET

, either way wont be going there at night anymore , got all cold n shivery thinking about it now ,

Think i take mr mossburg with me next time just for company brrrr!

Jim Berquist · Post by **Jim Berquist** » Tue Feb 26, 2008 11:34 pm

Just a thought! Some one is going state 10 reasons it can't work. I hope it is like the bumble bee. Aerodynamics's states it can't fly but they do!

Eric Won the Grate Ramjet challenge with a external version on a 180. I tried to find the You Tube video but I too was tired.

I think the tail cone would have to be enlarged to help with the restrictions caused by the jet. You would have to maintain the tune some way!

Sorry Shits n Grims didn't work out!

May be some one out there can find time to do a model of it some day.

I will keep thinking about it and see what my feeble brain can come up with.

Jim Berquist · Post by **Jim Berquist** » Wed Feb 27, 2008 12:43 am

Here you go Grim!

http://www.youtube.com/watch?v=b0KJwa5iWTY&NR=1

www.pulse-jets.com

Elliptical CC

mo vids

Big Bro

SEMI

Clipped tail

Here you go Grim!

the dead