For Your Comments & Criticism: Proposed Pulse Turbine

[larry cottrill]

Besides getting your thoughts on this design, this is a try at uploading from my PC here at work. I am not expecting this to work, because I think it will be blocked at the firewall, but we'll see. I'll write a description of the design after I know you can see it, but that may be this afternoon [several hours from now].

Here goes ...

L Cottrill
---------

[larry cottrill]

Well, amazingly enough, as viewed from here that actually seemed to work! It came out not as an embedded image, though [like my earlier shot of Maggie] but rather as a 'downloadable' image. Somebody let me know if you can see it that way, too!

L Cottrill
---------

[Bruno Ogorelec]

Well, amazingly enough, as viewed from here that actually seemed to work! It came out not as an embedded image, though [like my earlier shot of Maggie] but rather as a 'downloadable' image. Somebody let me know if you can see it that way, too!

L Cottrill
---------

Well, it looks embedded on my screen. Didn't have to download anything; it just popped up.

I still find this forum very confusing. Navigation is completely counter-intuitive and I never realyl know where I am.

The turbine looks like an interesting idea. It is probably far from efficient, but it is incredibly simple -- just the thing for an enthusiast.

Bruno

[kenneth]

Well, amazingly enough, as viewed from here that actually seemed to work! It came out not as an embedded image, though [like my earlier shot of Maggie] but rather as a 'downloadable' image. Somebody let me know if you can see it that way, too!

L Cottrill
---------

Well, it looks embedded on my screen. Didn't have to download anything; it just popped up.

I still find this forum very confusing. Navigation is completely counter-intuitive and I never realyl know where I am.

The turbine looks like an interesting idea. It is probably far from efficient, but it is incredibly simple -- just the thing for an enthusiast.

Bruno

He he , I have been changing the upload function many time the last 3 day , that is why some time you have been seeing the picture , and other times you had to download it !!

Bruno , please ask if you have any problems using the forum!!

kenneth

[Bruno Ogorelec]

He he , I have been changing the upload function many time the last 3 day , that is why some time you have been seeing the picture , and other times you had to download it !!

Bruno , please ask if you have any problems using the forum!!
----------

Kenneth, all the problems are in my head and you can't change settings there, I'm afraid. I've tried often without much success.

One thing I would like to suggest, though, is to make "newest post first" the default. Either that, or have a cookie remember my settings. I think it would be preferrable to scrolling down a long thread in search of teh latest posting.

Bruno

[paul skinner]

I've said it before, and I'll say it again. You're an amazing conceptual artist Larry. I wish I had 1/56th your talent.

I've had an idea of a flat plate valve with ball bearings that nest in little slope sided cups drilled into depression on the top of the plate, used to replace the petal valve on a pulsejet, and I can't think of any way of drawing it to make it look the way I want. I guess I'll just have to build the damn thing and test it first. Makes me jealous though of your artistic talent Larry

:) :)

[Ivar]

Larry,

First of all remember that whatever you do to the resonance pipe volume, whatever alternation to the flow will change its charecteristics.
I can cetainly way that you ned two bearings: one low-temp metal or ceramic ball to be put as far away from the engine as possible, and one carbon-disc bearing in the "red-hot" area. Are you planning to extract hp`s or measure airspeed?

[larry cottrill]

Ivar -

The idea was to obtain 'auxiliary' power, such as gearing down to drive a hydraulic pump or an alternator. This detail is from the original Cyclodyne(TM) design Production Prototype drawing; but it seemed to me that it might work in pulsejet exhaust streams as well -- perhaps in the exhaust end of an augmentor shell.

L Cottrill
---------

[Mike Kirney]

I like it. It looks sort of like an old Wincharger laying on its side. I'm not sure if the turbine wheel would spin or just oscillate through a few degrees. I think you could extract some energy if you attached the wheel to a ratchet/spring mechanism so that you could collect the energy of individual pulses, sort of like an old wind-up clock but in reverse. If you had two ratcheting mechanisms operating in opposite rotational directions, perhaps you could collect the energy of both exhaust and intake flow, and then use springs to store it briefly and then release it as smooth rotational motion.

[larry cottrill]

Mike -

That's why I'm thinking it would be better in an augmentor -- you'd have higher mass flow and you wouldn't have strong flow reversal. [It was definitely designed to be part of a constant-flow system.] And you're right -- it is a lot like the variety of Aeromotor rotors that were set up for tangential rather than axial flow. Around here, both types were used; the countryside is dotted with rotting steel towers, and occasionally some of the swiveling head assembly is still evident, though you almost never see one whole, much less functional.

L Cottrill
---------

[Ivar]

hey how about you have a shaft going trough the regular valved engine, and having a power turbine somwheer in the pipe, and have the sahaft`s end stick out the intake?

[larry cottrill]

Ivar -

Theoretically, you could do that, with the turbine located just behind the 'nozzle zone', but I think it might be more trouble than it's worth. The materials would need to be really good -- inconel or titanium; and the drag would have to be really low, so the inevitable backpressure as each pulse hits wouldn't mess up the remainder of the cycle. I think the augmentor location is the best chance at getting it to work -- very similar to the output of a turbojet combustor, after excess air is blended in, in the 'dilution zone'.

L Cottrill
----------

[cudabean]

Larry,

If all you want to do is extract a small amount of power from the pulsejet, You might consider a small stirling motor instead. With a stirling, you need not introduce anything in the exhaust stream, rather, you'd use the radiant heat. That way, you should be able to have the same thrust as before and still borrow some waste heat for other purposes.

cudabean

[Troy R. Legner]

Larry,
I was wondering if a cup type design like you find in a wind speed gizmo would work. It would harness the thrust head on. I think your concept would be interesting to have the pitch angle to the thrust variable. I'm thinking that maybe the dynamics and effeciency might be effected when a blade type prop is impacted at an angle.

I seen the engine pic you posted. It's a beautiful piece.
Troy Legner

[larry cottrill]

Larry,
I was wondering if a cup type design like you find in a wind speed gizmo would work. It would harness the thrust head on. I think your concept would be interesting to have the pitch angle to the thrust variable. I'm thinking that maybe the dynamics and effeciency might be effected when a blade type prop is impacted at an angle.

I seen the engine pic you posted. It's a beautiful piece.
Troy Legner

Troy -

The thing that I like better about this over a 'cup anemometer' is the simplicity of just cutting or punching the disk from a flat sheet, bending the vanes a little, and it's ready to mount on the shaft. Cut from ordinary sheet metal, good balance would be achieved almost automatically [if the cutting is accurately done]. The variable pitch thing would be yet another complication, something doable by master machinists [e.g. you] but unworkable for basement blacksmiths [e.g. me]. However, an easier way to achieve roughly the same effect would be to make the disk tiltable over a narrow range within the flow. I can see that pretty easy to do, if the disk and bearing set are out in an augmentor shell where the temps are reasonable.

Thanks for your comment on the picture - you can see a photo diary of the whole process [50 photos - count 'em, FIFTY] at http://www.cottrillcyclodyne.com/Maggie ... aggie.html

To be told by Troy Legner that you've made "a beautiful piece" of metalwork is a flattering compliment, indeed!

L Cottrill
----------