www.pulse-jets.com

Hello All:

It's interesting to see that someone [Mark] has found what appears to be a
rotary valve proposal for a pulse-jet. Too bad the text is unreadable. I didn't
think that I would have been the first person to suggest this type of valve.

I have been working on the software architecture for ...

Mark:

I'm still in the "visionary" stage, so nothing is built to take photos of.
But simply imagine a round butterfly valve on a car throttle body,
except the butterfly can rotate through 360 degrees instead of having
a "stop" when closed. The butterfly plate would also be thicker and
heavier, to ...

Hello All:

This is just an update on my work on the rotary valve
pulse-jet. I am focusing my attention on the design of
the engine control unit (ECU).

Since I own a product evaluation kit for one of Freescale
Semiconductor's HC08 family parts, that is my choice for
the microcontroller. The ...

Your description is sort of confusing; first you talk only in ratios, then you talk
only in volumes, no ratios. Is this engine some sort of secret design?

In any case, here is my opinion:

a) consider the cone to be part of the combustion chamber.
In this case, Pulso 1's CC of 56% is much larger ...

Tufty:

It's not merely "guesswork"... it's **educated** guesswork.

There are many things we can infer about the operation of a pulse-jet that
are based on fundamental physics. If we can set those issues to rest, we can
then focus on what we don't know.

I think Eric will agree that the problem ...

Hello Eric:

Here is how I approached the issue of short-term frequency variations

Parameters affecting pulse-jet operating frequency
---------------------------------------------------
Assume: Fpls = a* / (4 * L)

a* = speed of sound inside the pulse-jet (approx. 2100 ft/sec)
L = total engine ...

Note to ace_fedde:

It's always fun when you can see the light in someone's mind
suddenly light up.

You probably noted in my post of a day ago that ECU-controlled
spark ignition is one of the ECU outputs. And I had considered
using spark ignition on every pulse. But there are problems with
that ...

Hello Eric:

This is regarding your reply to Pulse-Jet Operating
Frequency Variations that is dated Sun Oct 25, 2009 12:03 am

Thanks for taking the time to reply on this topic.

However, it seem that I am miscommunicating or something, because
everyone seems to be answering questions that I am not ...

Hello All:

The forum discussion on the Rotary Valve Pulse-Jet has been very
informative for me, and I want to thank all the participants for
their input.

One of my goals for introducing the topic of a rotary valve
pulse-jet was to demonstrate the many benefits of this particular
valving method ...

Note to Rocket Man:

The attempt to convert a Dynajet from a reed valve to a rotary valve
probably failed because the pulse rate with a reed valve will be different
than the pulse rate with a rotary valve. The inlet flow restriction, and
probably the flow areas will be different, and they will shift ...

Eric:

The important parameter is the instantaneous (pulse-by-pulse) variation
in the pulse period (1/frequency). If it is actually less that 5% in the
short term, then that is acceptable.

For the reason I am asking the question, refer to "Rotary Valve Pulse Jet Engine"
in the "Valved Pulse Jet ...

Could you find a web link to the paper?
Or scan it and upload it?

If they had no success with the rotary valve, I need to find
out why. Of course, if this is true, then my engine concept is
also a failure. But with the information I have so far, there
is not explanation of **why** the rotary valve ...

Rocketman:

In your example, the pulse rate was measured as 220 Hz.
This is an average of 4.545 milliseconds between pulses.

What I am trying to find out is exact time between successive
pulses on a pulse by pulse basis. How much do any of the pulses
change from the 4.545 millisecond average?

SR71

Hello gone2fly:

If you care to look at the "Rotary Valve Pulse-jets" topic, you will see my sort of
"outside the box" concept for a high performance pulse-jet, and if my bubble is
going to be burst, it may as well be from someone who has a lot of experience
building pulse-jets.

You also may have ...

I agree that discontinuous (or pulsed) fuel injection is the way to go,
for several reasons. However, I would recommend a fuel pressure
much higher than 3 bar (42 psi in the U.S.). I was actually thinking
of about 7 bar in order to achieve better atomization of the fuel spray.

SR71