A little video showing the Dynajet pulsejet engine, the parts, how they work, and about the engine, followed by actually running it.
Its a tutorial video, the point is to show all the parts and explain them, if you are one of the impatient instant gratification types who dont care about all that and just want to see the engine run, dont complain, I didnt make this video for you.
The Dynajet is a valved pulsejet engine, the valve is the only moving part, and is responsible for keeping air from flowing out of the valve head.
In order to start the pulse jet, you need to blow a little bit of compressed air, which will open the valves, and fuel and air will move into the combustion chamber. When you provide a spark, the fuel burns and starts the engine running, and it no longer needs a spark once it is sustained.
As the fuel burns it creates a pulse of thrust, causing a jet of gas to shoot out of the back of the engine, after the fuel has burned the pressure inside is below atmospheric, and the pulse jet pulls in another charge of fuel and air, which gets re-ignited by some hot gas remaining in the engines tail pipe.
The fuel air charge then burns again, and produces another pulse of thrust, and the cycle repeats at about 280 times a second!
Pulse jets are a simple type of engine, and are popular as an alternative to expensive turbine engines. You can typically buy 10 or more pulsejets for the price of small hobby turbojet engine.
For not much more than the cost of a remote control ducted fan setup (between fan, motor, speed control, and batteries) you can have a real jet powered setup, capable of speeds over 250 mph!
Pulse jets are jet engines, they are not rockets, they require air to 'breath'. Also another misconception is that they have to be moving through the air to run, which they dont, and that they can not be throttled.
Valved engines can not be throttled as much as valveless pulse jet engines, because the valves require a little force to open, and also because on low throttle, the combusting gas will quickly heat and damage the valve, but they still can be throttled to some degree.
For best performance, and valve life, you should use methanol or an alcohol based fuel. When the alcohol fuel evaporates, it causes a great deal of evaporative cooling, and can literally form ice on the intake of the engine.
This keeps the valves and parts nice and cool, and also makes the fuel air charge much denser, producing more power.
Beck Technologies makes these types of engines, as well as valveless engines, in a number of designs and sizes, and we can also custom make things exactly to your specifications.
Check our site to see our wide array of engines and products.