3 years waiting, my Bailey jet engine finally arrives!

[Mark]

Thanks Robert for the philosophical slant. ha
But I am impressed with the 10 pound figure, if the Sport gets ~5.5 pounds of thrust and the Fast gets ~10 pounds with a slight increase in diameter that's significant. And all in a pound. My manual says my Sport jet weighs 14 oz. Of course you could lighten the head more too I guess.
I just don't want these valveless people to sweep the valved world under the carpet just yet. You know who you are. : )
I remember some previous post and scenes Down Under of a perfectly layed out track with fence for flying pulsejets and watching them zing round and round at a blinding speed. Neat stuff, yes.
Mark

[noclassmac1972]

Yes the flyin site is a lot of fun. I hope to be out there doing more jet flights over easter. And hopefully more videos

Now some more notes on the fast jet. The hole in the front is huge compared to the sport jet and will never run on suction because of it. Also the retainer has 2mm more lift. this alone makes a huge difference.

So its getting a hell of a lot more air and fuel in the front end which makes a bigger bang therefore more thrust.

On the valveless we have yet to see a motor in a model that is fast and that works. They are great noise makers at the present time and only that. But who knows what the future will bring :o)

Robert

[larry cottrill]

On the valveless we have yet to see a motor in a model that is fast and that works. They are great noise makers at the present time and only that. But who knows what the future will bring :o)

You're pushing against a solid wall (once the valve is closed) - we're pushing against a calibrated leak ;-)

In static tests, we're already beating the standard Dynajet for the same maximum tailpipe area, and that's using propane against the old Dynajet recommendation of white gasoline (a more energetic fuel per unit mass). Our main problems for model use now are:
(a) Carburetion of liquid fuel is still somewhat difficult to get right; and
(b) Overall physical bulk of the valveless engine is much greater for the same thrust (not length, but tailpipe bulk); and
(c) At high speed, we will tend toward over-rich running (if pressurized fuel) or air/fuel starvation (if carbureted) - exactly opposite to your "ram air" problems

It's all moot, anyway, under the present rules - you wouldn't be allowed to enter a valved engine with TWO 1.25-inch tailpipes! And that's how our valveless jobs with their rear-facing intakes (or 'recuperators' in some cases) would be viewed. A new class would need to be set up for valveless designs, and the two types would never get to compete head-to-head.

L Cottrill

[noclassmac1972]

Larry I think somebody better make a plane and fly it so we can see what the possibilities are with the valveless??? they only have that rule for the speed comps why not go out and have some fun with a modified stunter ??? Would have enough wing area to take the small propane tank :o)

But i will stick by my comment that Valveless engines are just there to make noise and heat and nothing else :o) untill I am prioved wrong

Robert

[Irvine.J]

Noclass...
I am building a big plane. (pictures recently in forum) in "Fueling A chinese" thread.
I am building and in the process of fitting 2 valvless pulsejets for flight use.
Liquid fueling a valvless PJ is a little trikky but by no means impossible.

As Larry said its all a trade off...

But i will stick by my comment that Valveless engines are just there to make noise and heat and nothing else :o) untill I am prioved wrong

I am more then happy to prove you wrong and shall do shortly. Although I cannot guarentee the time between flight and my wreckless rc skills induced fireball :)

[Rocket Man]

How long is the combustion chamber?

How long is the cone?

How long is the tail pipe?