"Thunderchine" 55 lb thrust pulsejet plans

[GRIM]

Hi Graham ,
Thanks for the comments , and thanks to all for the feedback re the cart , all feedback is good , negative or positive,

I have raced competition carts , they are fun , but I am looking for something a little more "EXTREME" ,

Agree also that being real close to one of these IS an experience , just filming from the noisy end was quite disturbing , but at the end of the day 50 odd pounds of thrust is not that much "push", any vehicle that will experience reasonable acceleration needs to be light and streamlined , with the centre of gravity as low as possible,

Top speed is not one of my priorities , High speed things should have wings not wheels, and yes I am aware that maybe a pulsejet is not the ideal powerplant for a lightweight good accalerating not high speed , BLAH BLAH ,

I agree, the head first is "MORE" dangerous in the event of a collision , I am not planning to collide, SHOULD one collide with some immovable object I am aware that it would likely be the last collision,

Rollcages are another issue , they may save you or they may trap you ,

For the time being this project is on hold , I shall re- evaluate once I have got the engine up to full power ,
currently working on a blower and the quarry owners ,

G

[Bruno Ogorelec]

Haven't visited in ages, and this is a very pleasant surprise. Great-looking engine. Congratulations!

[Graham C. Williams]

Hi Grim.
Ok, apologies for being a little negative.
I notice you've addresses the issues of Rolling resistance in your design. Bicycle type tires, light weight but strong construction. Thin with small contact area and high pressure.
Have you given thought to isolating the motor vibration from the frame. This reminds me of some of the old single cylinder motorcycles I've seen. In one example the front wheel was vibrating so much that the spokes were a blur. Connecting the motor to the frame was an issue that interested Paul Schmidt. I'm sure you'll find a drawing of his solution on this site somewhere.


Graham.

[GRIM]

Hello Graham ,
No need to apologise , no offense intended to you or anyone else ,
My choice of words was not appropriate, and I was being "general" wrt responses ,

Yes I agree, it may well be the case that the "vibration" (I use that term loosely to describe the mechanical vibration along with the sound energy that I felt shaking my ribs) MAY WELL be unbearable with the driver positioned so close to the engine , and the spokes coming loose is indeed a frightening thought,

Thanks again to all for the feedback , my next posts here will hopefully steer the thread back on course ,

G

[milisavljevic]

My next posts here will hopefully steer the thread back on course.

Is that a racing metaphor I smell burning?

Any and all developments eagerly awaited.

Cheers,
M.

[milisavljevic]

Dear Graham,

Good to see you back on forum again. Hope all is well with you.

Grim, M. and Rossco. What a team!!

Even more so if you factor in the v-a-s-t distances between us.

pacific-triangle.png

Cheers,
M.

[GRIM]

Heres a vid of the second run of my Thunderchine , running full vapor pressure the scale shows approx 17 kg , still nowhere near a flameout , and unfortunately I was unable to try different injector positions ,
I had just opened the flow control to admit some kerosene ,using my hybrid vapor / liquid setup, and the weld on the backplate split, , then the kero made its way into the CC , fried my spark generator too,

Some welding needed , and some new relays Ha !

Just the same an entertaining vid , be back for another go soon ,

Heres a link to the same vid but better resolution ,

http://www.mediafire.com/?hlzjyw5mtmt

G

[Mike Everman]

Beautiful! See the stinger setup get pushed out in the beginning?

[milisavljevic]

Hello Joe!

Congratulations on your second run! I see that the startup procedure has improved since last time.
Great run (while it lasted ) Remember: Any blowout you can walk away from is a good blowout.

17 kilos is not bad (ca. 70% of max.); was this with six (6) 2.0 mm ports? Or something different?

Btw., a third Thunderchine is now underconstruction, on a third continent. This one with ejectors!
The new Thunderchine is sc-9.1e2, with tapered intakes and a splitter* inside its transition cone.

Good luck with repairs and my fingers are crossed for a successful third test!

Cheers,
M.

*the splitter isolates the two intake ports during startup (think: baffle plate)

[GRIM]

Congratulations on your second run! I see that the startup procedure has improved since last time.
Great run (while it lasted ) Remember: Any blowout you can walk away from is a good blowout.

Hi M thanks , yes the 12 v starter motor blower works GREAT , but 280 cfm is probably a bit too much ,
and yes if I had been closer , the blowout may have been painful , relays burned ,a lesson learned ,

Yes 6x2mm orifices but in essence being fed bt 2x 1/8" bore stingers ,@ full tank pressure , see attach, next run will be with the original 1/4" bore stingers on vapor only, to establish the "sweet spot " then give it some stick with the liquid ,

terrifying, but great fun.

G.

Beautiful! See the stinger setup get pushed out in the beginning?

No didnt notice , but now you mention it , things are " happening " in them there inlets, something to do with a fairly large volume of air trying to change direction 180 odd times a second I guess

BAFFLED

G

[milisavljevic]

BAFFLED

"i can haz laffter wid dat baffle?"

Thanks for the new info and sketch. Remember to try moving the injection point out to ca. 25% from inlet plane.

Good luck!
M.

[GRIM]

Heres a small video of a “test” of this injector , flowing about 2500cc/min of water,
If there is any interest I will start a thread over in tools and construction , re this style of injector,
I think This thread should be related to the Thunderchine engines and things directly related ,

EDIT:
in the cold light of day I have reviewed the videos and as Mike cleverly noted , the injectors did indeed slide back about 35mm , (there is a witness mark in the tube) , so therefore the engine was actually running with the injection point at 53mm inside from the flare edge , pretty close to 25%

[milisavljevic]

The injectors did indeed slide back about 35mm [snip] therefore the engine
was actually running [snip] injection point at 53mm [snip] pretty close to 25%.

I would say "I told you so!" (move them back to 25%), but I already did (more than once). What?

Sometimes experience IS the best teacher. Always..?

Great project, mate!

Cheers,
M.

[GRIM]

Third run ,
I got a couple of decent runs in this afternoon, heres a piece of one of them,
I will post a link to a longer better resolution version once I get it uploaded,

After the start up, I disappear off screen , I am opening the kerosene valve ,
the scale reads between 23-24 kg , that was with the 100lb gas cylinder valve full open and the kerosene flow control full open,

Needs more fuel , BTW consumed 1Lt of kerosene during this run, then flamed out when the kerosene was used up ,

This "thrust rig " is very draggy , takes about 4-5 kg to get the engine and stand to slide whilst not running , (the engine and stand weigh in at about 17 kg) , so what you see is what you get , I make no claims about thrust , but I can say that it is Bloody scary,

Will post more once I have time ,

G

OH BTW , the injectors were at about 25% in from the flare ,

[Mike Everman]

Fan, freaking, tastic!