Search found 22 matches
- Tue Dec 01, 2009 2:11 am
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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 the ...
- Mon Nov 02, 2009 3:40 pm
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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 wi...
- Sat Oct 31, 2009 3:19 pm
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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 specific ...
- Fri Oct 30, 2009 2:19 pm
- Forum: Valved pulsejet forum
- Topic: Combustion chamber area compared to whole engine area ?
- Replies: 3
- Views: 5199
Re: Combustion chamber area compared to whole engine area ?
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 than...
- Tue Oct 27, 2009 8:59 pm
- Forum: Valved pulsejet forum
- Topic: Pulse-Jet Operating Frequency Variations
- Replies: 13
- Views: 15746
Re: Pulse-Jet Operating Frequency Variations
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 with "...
- Tue Oct 27, 2009 6:02 pm
- Forum: Valved pulsejet forum
- Topic: Pulse-Jet Operating Frequency Variations
- Replies: 13
- Views: 15746
Re: Pulse-Jet Operating Frequency Variations
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 length ...
- Tue Oct 27, 2009 1:01 am
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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 appro...
- Mon Oct 26, 2009 1:05 am
- Forum: Valved pulsejet forum
- Topic: Pulse-Jet Operating Frequency Variations
- Replies: 13
- Views: 15746
Re: Pulse-Jet Operating Frequency Variations
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 ask...
- Sun Oct 25, 2009 6:52 pm
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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, and ...
- Sun Oct 25, 2009 5:09 am
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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 ...
- Sat Oct 24, 2009 7:48 pm
- Forum: Valved pulsejet forum
- Topic: Pulse-Jet Operating Frequency Variations
- Replies: 13
- Views: 15746
Re: Pulse-Jet Operating Frequency Variations
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" foru...
- Sat Oct 24, 2009 7:42 pm
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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 f...
- Sat Oct 24, 2009 1:51 am
- Forum: Valved pulsejet forum
- Topic: Pulse-Jet Operating Frequency Variations
- Replies: 13
- Views: 15746
Re: Pulse-Jet Operating Frequency Variations
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
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
- Sat Oct 24, 2009 12:24 am
- Forum: Valved pulsejet forum
- Topic: How to Design Build and Test Pulse Jet Engine.
- Replies: 15
- Views: 25835
Re: How to Design Build and Test Pulse Jet Engine.
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 som...
- Sat Oct 24, 2009 12:03 am
- Forum: Valved pulsejet forum
- Topic: Rotary Valve Pulse-Jets
- Replies: 43
- Views: 53560
Re: Rotary Valve Pulse-Jets
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
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