Test have proven that rotary valves do not work. The #1 problem is, NO pulse jet engine runs at an EXACT same frequency all the time. Test have proven the pulse frequency of the engine varies by as much as 14 Hz. The test engine runs at about 200 Hz, the frequency goes up and down 5 to 7 Hz all the time and some times as much as 14 Hz.
It was learned that no mechanical devices and electronic device can open and close the valves at a speed that matches the exact speed of the engine.
A variable speed DC motor rotary valve system was built and set to run at 200 Hz to match the 200 Hz engine. The engine tries to run but it will not run on its own. The valves must open and close at the exact same speed as the engine. If the valve is off by 1 HZ the engine will fire with the valve open.
Combustion chamber pressure is about 18 psi. This pressure was used to operate a mechanical valve system that was never able to keep up with the same frequency of the 200 Hz engine.
If it were possible to make a pulso run at exactly 200 Hz all the time a valve system could be made to run at a matching speed.
Rotary valves do not work.
Moderator: Mike Everman
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Re: Rotary valves do not work.
I think any idea for Poppet Valves or Rotary valves must have the valve opened or shut by the internal pressure alown.As your PJ gets bigger new design ideas open up more.
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Re: Rotary valves do not work.
You might get away with rotary or other externally actuated valves if it were a very large pulsejet since the bigger ones operate at much lower frequencies.
Re: Rotary valves do not work.
The benefits of a rotary valve would be to reduce valve wear as seen in other designs, no? Why not use the only one-way valve with no moving parts? Tesla's valvular conduit?
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Re: Rotary valves do not work.
Oh, what if the fuel injector was controlled by the rotary valve? Then the timing of the explosion would have to match the valve's opening and closing because that's when the fuel would show up.