Pulse Jet Aircraft

[Bearcat]

Hey guys, I have been wanting to build a pulse jet and put it on a plane for a long time. I have very little experience in jets or other gas RC, and was wondering if anybody else has tried this or any advice/ideas. This is my first post on a new account I was using my brothers account "Flying Farm Kid" but I figured it was time to make my own. Anyways feel free to ask me any questions, I would appreciate any comments on the idea. I have a rough picture of what I think the plane would look like attached.

 

[Houndpup Rc]

Hey guys, I have been wanting to build a pulse jet and put it on a plane for a long time. I have very little experience in jets or other gas RC, and was wondering if anybody else has tried this or any advice/ideas. This is my first post on a new account I was using my brothers account "Flying Farm Kid" but I figured it was time to make my own. Anyways feel free to ask me any questions, I would appreciate any comments on the idea. I have a rough picture of what I think the plane would look like attached.

Hey, welcome to the forum! (Formally this time😉😂) Looks like a good starting point!👍

 

[Bearcat]

Thank you, I plan on posting threads and plans for most of my designs here now so I may have more stuff coming soon!

 

[Houndpup Rc]

Thank you, I plan on posting threads and plans for most of my designs here now so I may have more stuff coming soon!

Noice!👍

 

[Bearcat]

Depending on how this project goes it could be a contestant for the 2026 speed competition, assuming if follows all the rules...

 

[Houndpup Rc]

Depending on how this project goes it could be a contestant for the 2026 speed competition, assuming if follows all the rules...

I hope so!!! We need some more competition😂😂

 

[telnar1236]

Hey guys, I have been wanting to build a pulse jet and put it on a plane for a long time. I have very little experience in jets or other gas RC, and was wondering if anybody else has tried this or any advice/ideas. This is my first post on a new account I was using my brothers account "Flying Farm Kid" but I figured it was time to make my own. Anyways feel free to ask me any questions, I would appreciate any comments on the idea. I have a rough picture of what I think the plane would look like attached.

Might need a vertical stabilizer but otherwise looks great. The most important things to keep in mind with any gas plane and especially any jet plane are weight and heat. All that metal weighs something so you need a bigger airframe to carry it - and with a pulse jet that tube will be glowing red hot in operation so your airframe needs to be sufficiently separate from it and heat resistant it doesn't get destroyed. You also need a way to launch it that keeps you well away from the hot bits - there is no way to make a pulse jet safe to hand launch in my opinion

It also looks like you're working with a pulse jet design with valves. These are definitely superior in terms of performance but there are some big downsides too in the mechanical complexity and life of the valves - you need to replace them pretty frequently. If this is your first time building one, I might suggest a valveless design which should still give you plenty of power but be easier to build and require next to no maintenance

 

[telnar1236]

I hope so!!! We need some more competition😂😂

I don't know, I like where we're at right now - if no one else completes any runs I win by default

 

[Houndpup Rc]

I don't know, I like where we're at right now - if no one else completes any runs I win by default

I know!😂😂

 

[Mr Man]

Hey guys, I have been wanting to build a pulse jet and put it on a plane for a long time. I have very little experience in jets or other gas RC, and was wondering if anybody else has tried this or any advice/ideas. This is my first post on a new account I was using my brothers account "Flying Farm Kid" but I figured it was time to make my own. Anyways feel free to ask me any questions, I would appreciate any comments on the idea. I have a rough picture of what I think the plane would look like attached.

That engine model is just a mock-up, right?

 

[Bearcat]

That engine model is just a mock-up, right?

Yeah, I just threw something together so you guys could see what I was going for, the design is missing vertical stabilizers and and airfoil ect. its just a basic shape right now.

 

[Bearcat]

Might need a vertical stabilizer but otherwise looks great. The most important things to keep in mind with any gas plane and especially any jet plane are weight and heat. All that metal weighs something so you need a bigger airframe to carry it - and with a pulse jet that tube will be glowing red hot in operation so your airframe needs to be sufficiently separate from it and heat resistant it doesn't get destroyed. You also need a way to launch it that keeps you well away from the hot bits - there is no way to make a pulse jet safe to hand launch in my opinion

It also looks like you're working with a pulse jet design with valves. These are definitely superior in terms of performance but there are some big downsides too in the mechanical complexity and life of the valves - you need to replace them pretty frequently. If this is your first time building one, I might suggest a valveless design which should still give you plenty of power but be easier to build and require next to no maintenance
View attachment 258635

Yeah I am thinking I'll make the airframe bigger that was just a little mock up. The design I was going for with the pulse jet is supposed to be a straight valveless pulse jet, I have seen a couple online and AI seems to think it is a god option for simplicity and weight. I wanted to avoid the U shaped ones because they look like they would be much harder to fit on an airframe. I really dont know anything though so i could e totally wrong. Finally I was hoping to have some kind of low profile fixed gear that sat the airplane low but nose up to avoid using a bungee launch.

 

[Mr Man]

Yeah I am thinking I'll make the airframe bigger that was just a little mock up. The design I was going for with the pulse jet is supposed to be a straight valveless pulse jet, I have seen a couple online and AI seems to think it is a god option for simplicity and weight. I wanted to avoid the U shaped ones because they look like they would be much harder to fit on an airframe. I really dont know anything though so i could e totally wrong. Finally I was hoping to have some kind of low profile fixed gear that sat the airplane low but nose up to avoid using a bungee launch.

Never heard of a straight valveless…. But, I do know one called the thermojet, and it’s straight. But I am very interested to see how yours works!! (I’ve been wanting to make one sometime too 😂)

 

[Bearcat]

Updated Rough sketch closer to how the final one is going to look

 

[Bearcat]

Here is what AI said regarding the straight Valveless design:

 

[telnar1236]

Here is what AI said regarding the straight Valveless design:

I think AI is a bit confused there - Chinese style and FWE pulse jets have the inlet pointed in the same direction as the nozzle - this is what one looks like - a bit easier to package still though

Straight valveless pulse jets do exist, but they tend to be pretty awful since there's no way to prevent the exhaust from also flowing back out the inlet some. The big advantage in the U shaped designs is ease of throttling them up and down as far as I know. This is a good source on different pulse jet configurations

https://pulse-jets.com/valveless/

 

[Bearcat]

Thanks for that website! I will definitely be using that in the future, however for my first test I think I will try the engine I currently have designed, and if it works somewhat well that article says that a little forward movement creating ram air will help it along. If it doesn't work I will just cut the front intake tube on and attach it just like the picture above shows so that it points backwards. I really like this design and will probably copy it if I cant get mine to work:

 

[telnar1236]

Makes sense, let us know how it goes - I've never built a pulse jet before so my knowledge is limited and mostly theoretical

 

[Bearcat]

This is the video that I initially watched featuring the straight design valveless. He says that at higher speeds it behaves more and more like a ramjet where the incoming air counteracts the reverse thrust.

 

[Houndpup Rc]

This is the video that I initially watched featuring the straight design valveless. He says that at higher speeds it behaves more and more like a ramjet where the incoming air counteracts the reverse thrust.

*Video not available👍