Expert: Marc Ebelini - 9/3/2006

Question
I want the methodology design of thermodynamics and Aerospace for Pulsejet Engines.

Answer
Have no idea as to how much information you need. Basically pulse jets are like the old gasoline blow torches. They need heat to get them started or an external source of pressure to exert on the fuel. To start a pulse jet pressure is applied to the fuel tank to start the process. When the compressed fuel is forced into the firing camber through reed type valves it is ignited by a pulsing spark plug. When ignited the blast closes the reeds so the exploded fuel exits the out the tail pipe. Then the process repeats itself heating the fuel tank to develop the tank pressure to allow it to operate on it’s own. As the pulse jet moves forward the air entering the intake aids the forcing of the reeds to open while there is still some pressure in the firing chamber. The faster the jet moves forward the faster the reeds pulse until the engine reaches it’s maximum potential speed. The spark plug is no longer needed once the jet gets up to temperature.
The German V 1 rockets used pulse jets, but they used shutters as the valves. They got them started by launching down long slides to develop the forward speeds to allow them to operate on their own. Many failed to sustain themselves only to fall into the English channel. To learn more your can build one from a kit as I did decades ago that almost got me thrown out of the neighborhood it made so much noise. This looks like a good web site to start with. http://www.airtoi.com/ljet.htm Hope I was of some help. There are endless web sites that are dedicated to pulse jet engines should you need more information.