FWE Theory - Focused Wave or NOT Focused Wave?

[Eric]

At embry you can do all kinds of stuff from airplane mechanic to avation electronics and aerospace engineering. If you go to embry for aerospace engineering you can basically get a co-op job right as you are in school at big name companies/agencies and usually when you graduate you are offered jobs with those companies. They have probably the highest job placement because of that. A guy I know who used to have a wind tunnel / engineering firm in NYC had like 2 employees from embry.

Ok, so I am trying to make a direct injection pressure tap for the thermojet-fwe I made but was wondering where are some common places that you can find klien valves/regulator's. If I cant find anything easy I will try to locate a high pressure spot in the exhaust and then have the injector right at the edge of the intake. either that or make a vaporizer coil which feeds back to the tank for pressure. I'm wondering if some kind of bladder tank might work.

Eric

[larry cottrill]

Ok, so I am trying to make a direct injection pressure tap for the thermojet-fwe I made but was wondering where are some common places that you can find klien valves/regulator's. If I cant find anything easy I will try to locate a high pressure spot in the exhaust and then have the injector right at the edge of the intake. either that or make a vaporizer coil which feeds back to the tank for pressure. I'm wondering if some kind of bladder tank might work.

Eric -

In this case, the Cline regulator won't work - it only delivers at ambient pressure, so you have to have a venturi to pull it down. Of course, each cycle will try to pull it, but it's not going to respond to a pull that only lasts a couple of thousandths of a second, I'm sure! You need a regulator with a screw that clamps a spring down on the diaphragm, so there's some overload. Mine was made using my old high-volume air regulator [only 0-26 PSI or so], fitted with a propane fitting robbed from a totally inadequate cookstove regulator that I got at Menards for less than $20. I put them together with Teflon tape. Just find yourself the biggest used low-pressure air regulator you can find, and put the propane fitting on. An acetylene regulator for a welding outfit might work, if you can find a nice big one. An oxygen regulator probably wouldn't be a good choice, because of the high-pressure valve pad [normally working against up to 2250 PSI] which would be highly restrictive to a low-pressure supply.

From my first edition of jetZILLA, here is where to find the Cline regulator and other little parts:
www.billsroom.com/pcfs

L Cottrill

[larry cottrill]

Eric -

In a quick look on eBay, I only found one that I liked the looks of. It must be a whopper, because it has 3/4" NPT threads for the inlet and outlet ports. It is apparently designed for sandblasting, which would be a pretty high volume / demand use:

http://cgi.ebay.com/ebaymotors/ws/eBayI ... gory=34999

L Cottrill

[Eric]

That site wanted 60 bucks for the clien valve!!! I went to the local hobby shop, which for some reason, actually had all the stuff I needed, and also had it all for under 10 bucks. I got a 12 ounce RC airplane tank, a fitting for the pressure tap, and a little one way presure tap valve system($2). So all in all I am very happy since I got everything pre-made and didnt have to screw around with welding up a tank.

I made a little fuel spray injector with a little parrallel propane start up line. I figure I will start it up on propane in this beautiful 20 degree weather and then let it warm up a bit, and try to ease into pure methanol opperation. Ill put up some pics of the setup wether it works or not. If the pressure system does work I will try to start it up using using the aircompressor basically making the fuel nozzle act as an airbrush with no intake venturi and then have the tank fill up. Im really hoping the tap will work. If it doesnt I will be forced to use alternative means.

Eric

[Mike Everman]

I can't wait to try this too. Looks like you'll beat me to it Eric! Trying it tomorrow?

[Mike Everman]

I couldn't wait to find out how the Chinese/FWE will do with a divergent exhaust, so I made one tonight. Tomorrow's my 7 yr old Scott's "Daddy Day", and he wants us to run a jet, so I wanted to be ready to test something that's important to very few people. ;-)

Made the intake from a 90 emt 3/4" bend; just looked kind of cool at Home Despot. Entry to the cc is L/8, overall length is 42", intake is L/6. Exhaust throat is L/6. Injector slides and is 1/8" brass tubing.

I'm anxious to see if it gets similar thrust to the recent "Bride" tests, as they are the same other than this has a bit smaller intake.

Enough, g'night!

[Mark]

Mike, your EMT side port creation is kind of pleasing to look at. If the liquid fuel thing is worked out, just imagine little wheels and a leash. You could take it out for a walk around the block or run alongside it.
Mark

[Eric]

Yea I am going to try it when I get back up today. Just got up to get a snack and head back to bed.

I am going to first fill it up with water and just have the pressure tap connected and have the engine run on propane and see if it forces any water out of the tank, that way if it does work I dont have a uncontrolled stream of vaporized pressurized fuel flowing into the engine. If that works I am going to run back to the hobby shop and pick up a needle valve type thing and a inline refueling port for the tank.

If I can get it all to run I am going to put it on a little frame which will be mounted to a control line cross country ski, although maybe I should get a smaller than 12 ounce tank for something like that.

Eric

[larry cottrill]

If you use a regular U-control handle and dual lines, and could find a very easy working small valve [say, at the hobby shop], you could rig it so your handle would give you throttle control - pull 'up' to throttle down, pull 'down' control to speed up. [May seem like a strange orientation to non-pilots, but that's how it works in real aircraft - pulling the nose up reduces speed and vice versa. The control handle would also resemble how an aircraft throttle works that way - push the top of the handle forward to add power.]

That would give you something to do besides just stand there and watch it go around. The only gotcha is that it only works if it's going fast enough to keep the lines pulled tight centrifugally. You shouldn't have any problem with that as long as your engine is running!

That's going to be pretty heavy and pretty fast - you should get a standard set of SS control lines at least 52ft long, and maybe more. Dizziness actually can be a hazard with fast craft!

L Cottrill

[Eric]

Well we got a major ice storm today, I havent even gotten out of the driveway yet.

For the ski I planned on making V shaped drag wings that can be progressively smushed to become more aerodynamic until I get the hang of it. I have flown U control planes before, it can get very disorientating. I plan on sitting on a nice comfortable rotating office chair ;).

The ice does provide a nice surface to walk on top of the snow, the jet ski should be very fast. I have a pretty big field, I was thinking of using 2 pieces of 150 pound test shark fishing line, maybe 100 feet long or so, and having a wing or the engine pointing so it pulls outward.

Eric

[Eric]

This is crazy, the township never even came to put cinders on the road, and the road is litterally covered in 2 inches of solid ice from the melted snow pack and the freezing rain on top of it. Unfortunately I live 2 miles from my shop. Maybe tomorrow, I hope.

Eric

[larry cottrill]

Ok here are the single cycle wave propagation. Well its almost 1 cycle. I did .01 second run on uflow. When I get more free time I am going to do a true 1 cycle with 40 data spots so it makes a really nice terrain mesh.

Eric -

I have re-styled one of your drawings and cut the time in half, to more closely limit it to a bit over one actual cycle. Can I get your permission to use this on my FWE page, with a credit like 'from an original plot by Eric Beck'? I may add some .001 second marks, if I can figure out how they'd lay out, approximately. Or, if you know where they'd hit, spot them in for me if you like, just on the line at the nose of the engine.

L Cottrill

[Eric]

Yea, you can use the picture, but..... I will have to look on my originals to see how much time has passed.

Althought the UFLOW temperatures dont match the working engines temperatures and the frequency is off accordingly. You might want to do one like that with a larger timeframe, and label one cycle, that way you can see how the waves interact down the tailpipe while the combustion chamber fuel charge is being burnt. If you take the aprox frequency of 250 htz from my tests and apply them to the picture one cycle would be .004 seconds. If you want I could probably scale up the y axis to better show the lesser details.

I dont know if you can do it with paint and have it work nicely, but it would be interesting to see a graph of multiple cycles pasted together from the initial spike.

Eric

[hinote]

I went to the local hobby shop, which for some reason, actually had all the stuff I needed, and also had it all for under 10 bucks. I got a 12 ounce RC airplane tank, a fitting for the pressure tap, and a little one way presure tap valve system($2).

Eric

Eric--please contact me at:

hinote@nctv.com

Bill

[Eric]

Oh yea, I should mention that the hobby shop screwed up bigtime when they sold it to me, the MSRP is over $25! The lady didnt know how much it was so she just said " oh probably about $2".

Eric