How do you design the "valve" in a Valved Pulse-Jet
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amorris013
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How do you design the "valve" in a Valved Pulse-Jet
In my physics class, my teacher and I have begun researching valved pulse jets, in hopes of designing our own. However, the design for the the valve still eludes us. We are looking to design a simple petal valve jet, capable of producing roughly 4-5 pounds of thrust. I downloaded the pulse jet calculator, so I have the necessary dimensions, I just need to learn how to put the pieces together, and how they all work. Any answers will be greatly appreciated. Thanks
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Rocket Man
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Re: How do you design the "valve" in a Valved Pulse-Jet
The valves are the tricky part of the engine. I have designed my own test equipment its not real fancy but it works. There are many things to consider.
The valves are typically made of blue spring steel or stainless. As the valves open and close they beat themself to death. Typical problem is the metal cracks then brakes and you loose one of the pedals. The tips brake off and the engine stop running.
Thicker metal makes stronger valves but stronger valve are harder to open. Thicker metal also increases the frequency of the valve.
The valves open and close over and over several 100 times per second. They open fast then slam shut. Each time the valve slams shut the metal bows down into the air intake opening forcing the metal into a temperary dish shape. This causes the metal to crack then it brakes. The air intake opening need to be sized small enough so you get long valve life. About .350" to .375" works great for .010" blue spring steel. You can put multipal holes under each pedal. Holes can be round, slots, squares, rectangles, ovals, etc.
If the reed valve metal is made thicker it causes the frequency to increase you can count that my making it longer this reduces the frequency. If you make the valves out of .030" blue spring steel they are plenty strong but each pedal has to be made much longer to maintain the same frequency the disadvantage here is the larger diameter pedal valve is very hard to get inside of a small combustion chamber.
The design of the reed valve retainer is extremely important too.
There are so may things to consider I would write a book on just the valves along. There are pedal valve and argus valves and others too.
If you need plans send me a private message with your email address I will send you plans it will get you started. I have plans for engines 5 lbs thrust to 250 lbs thrust. They will run on propane, gasoline, alcohol, kerosene.
http://www.youtube.com/watch?v=QkOR8IZPsFg
http://www.youtube.com/watch?v=s5KInr3C9vQ
http://www.youtube.com/watch?v=jqxjgmel ... re=related
http://www.youtube.com/watch?v=1VNyTsUT ... re=related
The valves are typically made of blue spring steel or stainless. As the valves open and close they beat themself to death. Typical problem is the metal cracks then brakes and you loose one of the pedals. The tips brake off and the engine stop running.
Thicker metal makes stronger valves but stronger valve are harder to open. Thicker metal also increases the frequency of the valve.
The valves open and close over and over several 100 times per second. They open fast then slam shut. Each time the valve slams shut the metal bows down into the air intake opening forcing the metal into a temperary dish shape. This causes the metal to crack then it brakes. The air intake opening need to be sized small enough so you get long valve life. About .350" to .375" works great for .010" blue spring steel. You can put multipal holes under each pedal. Holes can be round, slots, squares, rectangles, ovals, etc.
If the reed valve metal is made thicker it causes the frequency to increase you can count that my making it longer this reduces the frequency. If you make the valves out of .030" blue spring steel they are plenty strong but each pedal has to be made much longer to maintain the same frequency the disadvantage here is the larger diameter pedal valve is very hard to get inside of a small combustion chamber.
The design of the reed valve retainer is extremely important too.
There are so may things to consider I would write a book on just the valves along. There are pedal valve and argus valves and others too.
If you need plans send me a private message with your email address I will send you plans it will get you started. I have plans for engines 5 lbs thrust to 250 lbs thrust. They will run on propane, gasoline, alcohol, kerosene.
http://www.youtube.com/watch?v=QkOR8IZPsFg
http://www.youtube.com/watch?v=s5KInr3C9vQ
http://www.youtube.com/watch?v=jqxjgmel ... re=related
http://www.youtube.com/watch?v=1VNyTsUT ... re=related