Now that I'm retired and free from the distractions of golf and cycling I'm thinking of a suggestion back in the day when I was working at Loughborough University and messing around with a Reynst Pot made from an Ambrosia Creamed Rice tin, that I used as a demo in lectures. The question was, could it achieve vertical take-off? The obvious answer was no, as firing it up on kitchen scales showed that it generated just a few ounces of thrust.
However, it was a bsic set-up, with no diffuser below the inlet hole. There would have to be a kind of tray for the fuel, and it would no longer be exposed to directly to the incoming totoidal vortex of fresh air and combustion products.
Its good to see that there is still some life in the forum (well done Theo) so any thoughts would be much appreciated.
Reynst pot thrust
Moderator: Mike Everman
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Re: Reynst pot thrust
Hey Vic. Glad to see you back, congratulations on getting out of the rat race.
Sounds like a fun experiment. Go for it!
Sounds like a fun experiment. Go for it!
Re: Reynst pot thrust
I toyed with that vertical takeoff thought too but didn't really have enough patience to keep trying. Some u-bend snorkels were tried to redirect the thrust downward and also thought given to somehow having the hole/exhaust face downward and feed the jam jar jet fuel differently. I like snorkels because they increase the thrust yet still breathe in and out through the same port like a jam jar jet and don't make as much noise as a typical pulsejet.
This way too heavy shape made 360 grams of thrust for enough time to lift off for a short entertaining bit, again if only it weren't so heavy.
https://www.youtube.com/watch?v=30u_qEhm_uk
And this other jam jar jet with snorkel seemed just peppy enough IF the weight could be made ultralight and made to run inverted.
https://www.youtube.com/watch?v=mDrdUy-LWHY
Some other basic snorkelers
https://www.youtube.com/watch?v=g2ZwuyALwxg
https://www.youtube.com/watch?v=LPe29o0OUSw
https://www.youtube.com/watch?v=ChtLqS7tRyo
https://www.youtube.com/watch?v=T-EoSOfaplo
https://www.youtube.com/watch?v=j7tGX_5B_Jk
This way too heavy shape made 360 grams of thrust for enough time to lift off for a short entertaining bit, again if only it weren't so heavy.
https://www.youtube.com/watch?v=30u_qEhm_uk
And this other jam jar jet with snorkel seemed just peppy enough IF the weight could be made ultralight and made to run inverted.
https://www.youtube.com/watch?v=mDrdUy-LWHY
Some other basic snorkelers
https://www.youtube.com/watch?v=g2ZwuyALwxg
https://www.youtube.com/watch?v=LPe29o0OUSw
https://www.youtube.com/watch?v=ChtLqS7tRyo
https://www.youtube.com/watch?v=T-EoSOfaplo
https://www.youtube.com/watch?v=j7tGX_5B_Jk
Presentation is Everything
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Re: Reynst pot thrust
360 grams is really good, I'm thinking.
My approach was making a pulsepot helicopterish thing, but I could not get it to sustain:
https://www.youtube.com/watch?v=mXgAOvkrOF4
My approach was making a pulsepot helicopterish thing, but I could not get it to sustain:
https://www.youtube.com/watch?v=mXgAOvkrOF4
Mike Often wrong, never unsure.
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Re: Reynst pot thrust
That propellor attempt made me wonder if two ultralight mini thin metal jam jar jets on the tips of a propellor could lift off? They'd have to be really aerodynamic, perhaps partly built into the blade or some other clever concept. Fun to think about albeit a monumental challenge.Mike Everman wrote: ↑Thu Oct 19, 2023 4:23 pm360 grams is really good, I'm thinking.
My approach was making a pulsepot helicopterish thing, but I could not get it to sustain:
https://www.youtube.com/watch?v=mXgAOvkrOF4
https://www.youtube.com/watch?v=tapt0Vzv1Eo
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Re: Reynst pot thrust
I’m thinking more like one rev per pulse on a smaller propeller, maybe.
Wonder if the snorkelers would work if bent over and trmendously lightened. Your 360g seems a reasonable weight budget without getting too crazy with materials.
Wonder if the snorkelers would work if bent over and trmendously lightened. Your 360g seems a reasonable weight budget without getting too crazy with materials.
Mike Often wrong, never unsure.
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Re: Reynst pot thrust
Another thing that might be fun is if you could make a jam jar jet that could power a toy hovercraft. That is, have the craft jump up and down from the push of the exhaust while also taking in fresh air from around the skirt before the cycling stops. Here's something different than that but if somehow a jam jar jet contraption could sustain upside down and push off the ground repeatedly, that would be cute.
https://www.youtube.com/watch?v=SzxWnYo2HT4
An interesting buzzing feedback effect with a CD balloon hovercraft around the 6 minute mark
https://www.youtube.com/watch?v=yAI3qTV92fo
I toyed with a lid like this lighting the top hole but it's too perky when lit.
https://specialeventsofne.com/images/pr ... over-1.JPG
https://www.youtube.com/watch?v=SzxWnYo2HT4
An interesting buzzing feedback effect with a CD balloon hovercraft around the 6 minute mark
https://www.youtube.com/watch?v=yAI3qTV92fo
I toyed with a lid like this lighting the top hole but it's too perky when lit.
https://specialeventsofne.com/images/pr ... over-1.JPG
Presentation is Everything