Search found 1241 matches
- Mon Oct 20, 2008 7:32 pm
- Forum: Valveless pulsejet forum
- Topic: Mike's Build Log
- Replies: 441
- Views: 325572
Re: Mike's Build Log
Bill, what thrust were you getting on that motor in the picture? Looks nicely involved! As I recall, that was at 4.8 lbf. This motor needs a little more work; the intake and the fueling are under suspicion for improvements. A motor this size needs increasing precision in its construction to realize...
- Mon Oct 20, 2008 6:49 pm
- Forum: Valveless pulsejet forum
- Topic: Mike's Build Log
- Replies: 441
- Views: 325572
Re: Mike's Build Log
1.93" Mike: I find it intriguing that you're using such a short LOA in relation to the CC ID. Long ago I discovered an important parameter I've adhered pretty closely to: The CC diameter is proportional to the length of the engine. The reason for this is that the frequency is (of course) tied to th...
- Wed Oct 15, 2008 2:57 am
- Forum: Valveless pulsejet forum
- Topic: Mike's Build Log
- Replies: 441
- Views: 325572
Re: Mike's Build Log
Here's another historic precedent--the Ecrevisse B by SNECMA. Before the other knowledegable on the forum correct me: the image is of the model "C" Ecrevisse. I still find it amazing to contemplate how much development SNECMA accomplished in the postwar environment, through the '50's. It's sad to s...
- Tue Oct 14, 2008 7:22 pm
- Forum: Valveless pulsejet forum
- Topic: Mike's Build Log
- Replies: 441
- Views: 325572
Re: Mike's Build Log
Here's another historic precedent--the Ecrevisse B by SNECMA. I drew in the red arrow to clarify.Graham C. Williams wrote:Hi Bill and Joe.
Take a look at the Snecma - AS1. For That matter it's not too far from the TYPE06 either. They are probably doing much the same thing.
- Tue Oct 14, 2008 5:30 pm
- Forum: Valveless pulsejet forum
- Topic: Mike's Build Log
- Replies: 441
- Views: 325572
Re: Mike's Build Log
Mike:
Are you using a stepped transition cone just after the CC--or am I just imagining things?
Are you using a stepped transition cone just after the CC--or am I just imagining things?
- Tue Oct 14, 2008 5:21 pm
- Forum: Valveless pulsejet forum
- Topic: Multiple inlets
- Replies: 18
- Views: 12476
Re: Multiple inlets
There's a lot of material on this site about the Kentfield and similar efforts, using a 4-tube inlet array. Use the search engine to find related material! I believe that 4 intakes may be optimum; my theory is that the wetted area of increasing tube arrays dilutes any advantage they would otherwise ...
- Tue Oct 14, 2008 4:44 pm
- Forum: Valveless pulsejet forum
- Topic: Multiple inlets
- Replies: 18
- Views: 12476
Re: Multiple inlets
SRL did this hovercraft project some years ago ('02 I think) and powered it with multi-inlet PJ's.
Here's a photo of that project.
Here's a photo of that project.
- Mon Aug 25, 2008 1:55 am
- Forum: Off topic forum
- Topic: Good news and Bad News re Vertical Thrust Stand
- Replies: 1
- Views: 3229
Good news and Bad News re Vertical Thrust Stand
I've tried my version of a vertical thrust stand to measure the thrust of my entry in the 1.5L Valveless PJ contest. The good news is, the thrust measurement seems to be quite successful; in fact--in spite of a very high refresh rate on my digital postal scale, the value indicated was quite steady. ...
- Wed Aug 20, 2008 6:57 pm
- Forum: Off topic forum
- Topic: The ElectraFlyer C plug-n-fly electric plane
- Replies: 10
- Views: 8271
Re: The ElectraFlyer C plug-n-fly electric plane
The cooling requirements of this system, both batteries and motor can not be underestimated. There is a great deal of watts being dissipated somewhere, as this is a very inefficient system! I'm betting most folk would find this out later rather than sooner. That's a Lemco motor, 90% efficiency. The...
- Tue Aug 19, 2008 7:05 pm
- Forum: Off topic forum
- Topic: The ElectraFlyer C plug-n-fly electric plane
- Replies: 10
- Views: 8271
Re: The ElectraFlyer C plug-n-fly electric plane
Hi Bill, I think your perfectly correct, my view is that motor gliders just have not been developed enough as the original IC engines did not add sufficiently to the overall combination, the electric conversion makes complete sense to me. Viv One of the very real advantages to an electric power pac...
- Tue Aug 19, 2008 6:16 pm
- Forum: Off topic forum
- Topic: The ElectraFlyer C plug-n-fly electric plane
- Replies: 10
- Views: 8271
Re: The ElectraFlyer C plug-n-fly electric plane
This is a beautiful conversion of a motor glider to electric power, very impressive peace of work I think. The modern motorglider is very efficient--and maximizes the limited power available from an electric power package. The primary power consideration for this type is an acceptable climb rate--t...
- Tue Aug 19, 2008 12:22 am
- Forum: Unconventional, Multi-Mode and Hybrid Jets
- Topic: Pressure gain combustion ?'s
- Replies: 17
- Views: 20920
Re: Pressure gain combustion ?'s
I'm wondering if someone made a really long turbine and inside instead of a flameholder they had 5 pj's or ramjets.....must draw a pic to get my thought out I guess. The reality of your concept is, there are severe limits to the possible length of the shaft. Specific data is available to us at the ...
- Thu Aug 14, 2008 2:12 am
- Forum: Off topic forum
- Topic: Brand new steam locomotive video
- Replies: 6
- Views: 5918
Re: Brand new steam locomotive video
...and here's the historic result:Viv wrote:Hi Simon
Never got to see the engines there but it was on my list, there is another engine in the news the Oliver Cromwell, just restored and running again
Viv
http://www.youtube.com/watch?v=eNhJ0ysM ... re=related
--a beautiful setting for the event too!
- Sat Aug 02, 2008 7:44 pm
- Forum: Off topic forum
- Topic: Brand new steam locomotive video
- Replies: 6
- Views: 5918
Re: Brand new steam locomotive video
I have ridden the steam engines that still operate in both the peak district and in North Wales for the old slate quarries, my own passion is for the Victrorian beam engines used for pumping, Papplewick in Nottingham is a superb example and the Crofton beam engines on the Kennet and avon canal. Viv...
- Sat Aug 02, 2008 3:12 pm
- Forum: Off topic forum
- Topic: Brand new steam locomotive video
- Replies: 6
- Views: 5918
Re: Brand new steam locomotive video
Being a lifetime steam power fan, this is interesting news and will add to the already substantial stable of operating British steam locos. Frankly, it's a little bit traditional--a sad thing for me because I like to see "progress" toward modern steam power whenever possible. My personal favorite is...