Valveless pulsejet workflow simulation online

[Alex Eng]

I just would like to give a link to the neighboring valved subforum, because the topic is general, and concerns directly valveless engines too.

By the way, the working process of a valveless engine is fundamentally different from a valved engine even in the form of the instantaneous parameter curves. Moreover, the difference is in pressure, and in temperature (it is lower, and the shape of the curve is completely different), and in gas-air velocities. The most interesting thing about a valveless engine is the gas velocity at the intake, and also how cold air moves through the pipe. Well, and the thrust force that the intake pipe gives is really greater than the part that the resonance pipe generates.

In other words, we are not interested in how to make an engine using a cutter and welding, but we know how to check it before welding. And we suggest you try it too.

In short, if you are interested in what happened, this is here.

[Alex Eng]

The program calculates on the server, the data is only transferred from the phone or from the computer to the server and back. Therefore, any calculation of engine operating cycles can be done even on the phone. Now the program works in the basic version, without any special settings or corrections of anything. Therefore, some results may not match real engines. For now. But at least it provides an order of magnitude and high-quality correspondence.

If anyone is interested, here are screenshots from the phone.







This is here - https://pulsejet-sim.com

[Alex Eng]

We get step by step a lot of interesting things with help of our program .

One of such ones is here. We tried to start up valveless pulsejet engine with wrong parameters - in this case, it was 2 very short (150 mm length) inlet pipes of 50 mm diameter, but the resonant pipe was only 40 mm, combustion chamber was 80 mm diameter and 300 mm length.

You can see the engine with such strange geometry is starting very difficult, but finally it somehow cleared up and started .



Well, we think it is possible on a computer only, because in reality such engine will not start, or it will be very difficult.

[metiz]

Very interesting Alex, thank you for your contribution!

[Alex Eng]

Thank you too! Hope you already tried to simulate some engines.

Now we are working with parametric study function, it works on 70% for small valved engine, and it will be ready for all very soon, as soon as we will make standard deviation for all diagrams.

This is a long story, really. All this was a topic of my PhD dissertation many years ago (about 40 and it was absolutely secret ), but I did not finish a lot then, by any reason (mainly because in Russia perestroyka happened ). Now I had a little time before my doctoral dissertation defence, I recollected about all this by chance and solved to finish it. You can see now what happened from it .

[Alex Eng]

We already can offer possibility of parametric study of your valveless pulsejet, and now such study gives the following graphs:



It is small valveless engine with 40 mm cylindrical resonant pipe diameter and with 50 x 250 mm inlet pipe. Our model and program give maximum thrust on about 1200-1300 mm resonant pipe length. It is interesting, that the valved engine with similar geometry has maximum thrust on 900-1000 mm pipe length (see the valved subforum).

You can research your valveless engines too, even on your telephone .

Unfortunately, we cannot validate our results, because have no cutters and no welders, and also don't know the real and full experimental data with all needed engine geometry and parameters. But we hope for getting it in the future (you can see which data is necessary on our program ).

[Alex Eng]

Now you can collect all the diagrams of changes in instantaneous parameters into one - here is an example of collecting pressure, temperature in combustion chamber and gas-air velocities in the intake and resonance pipes - all what scientists like very much :



And if you click on the parameter rectangle, the curve can be easily removed from this diagram.

You also can get valveless pulsejet speed characteristic and we are sure it is impossible to find something similar somewhere else :



You can try it yourself - this is here!