Hello. 1st post here. Two videos

[Pete Doyle]

Hi. This, as noted is my first post on the Ramjet forum. It is a follow up to my first post on the Valveless forum (Hello Valveless)
I was encouraged by Larry C. to post video of two small ramjets that I've made. Here they are. Both are short. One of the jets is a fairly direct descendant of Maggie Mugs. The other is related but uses a travel cup for the inlet, one-half a fire extinguisher cylinder for the CC and an 8oz. tomato sauce can for the exhaust. Both use stainless sink strainers for flameholders. Both use simple copper tubing injectors, They are both held together with Hi-temp furnace cement in much the same way as Larry used JB weld in the original Maggie. Ignition was by BBQ piezo, despite the presence of spark plugs. Air is from an electric leaf blower.
Pete

Ramjet2 video.avi [ 1.23 MiB | Viewed 534 times ]

Maggie muggs2 Movie.avi [ 843.58 KiB | Viewed 534 times ]

[larry cottrill]

Pete -

Thanks for posting these. I think the use of the ceramic type cement is a big improvement. My only "negative" comment is that I don't think your blower packs enough wallop to really make them run out. The second one, judging by the discoloration of the front end, looks like you're getting some combustion out in front of the flameholder. Any chance you can obtain a more powerful air source?

Other than that, they look good. If you were willing to re-build one of them with a plain conical diffuser, potential results would be even better (hint: I knew the front end of Maggie wasn't ideal when I designed her; I was just using whatever I could conveniently find). Have you seen the video of Steve Bukowsky's little welded steel ramjet, based on the design of the Hiller rotor tipjets? Look way down on this forum for a title something like "Steve's TLAR Ramjet" (you have to find the little .zip file and download it) -- his video is a perfect example of how they should run. Man, he must have had a heck of a blower, though.

Thanks!

L Cottrill

[Pete Doyle]

Larry: Thanks for the reply. Actually, the blower that I used has more power. I had it on low power for the video. I did run it once on high power when I turned a small propane bottle upside down and went to liquid propane. That was an experience, very impressive. I will try to get some usable video. Going it alone, though, is tough; I need four hands.
I find that running one of these little jets optimally is a two man job. Getting usable video is definitely so.
There is some burn in front of the flameholder when I start the little guys, a byproduct, I'm sure of inexperience and going it alone. I start them w/o air and then add fuel and then focus the blower. Once I get the air in place and focused, all the burn is in the CC.
I will definitely check the post that you have recommended.
Pete
PS - The video format that my camera uses is not as compact as others, hence the short clip. I have edited it again to about twice the length of the present post. Would it be helpful to see that longer version?