Well Viv, and John,
I think you can be totally right there when talking about scam and the hugh amount of "new engine types". But as you probably noticed its not all scam.
I used to, for many years, follow all the news about automotive engines. Many new promising concepts past but never made it to reality.
The simple reason is that our old friend, the i.c. piston engine, has been developed so far and has become so sofisticated.
Many new designs that might have a better efficiency on paper, simply cannot catch up with this development position of the i.c. piston engine, and lose the race.
Back to our PDE-turbine. Well that's the first thing I'm asking myself: Is this really an PDE in terms of D
etonation, or stands the D in PDE for D
There is some interesting thread, explaning detonation, in the PDE forum:http://www.pulse-jets.com/phpbb3/viewtopic.php?f=12&t=1418
and there is more there.
Many times the word detonation is used to easy, just to describe an explosion (so a deflagration). With detonations the shockwaves travel faster than the speed of sound, for deflagrations they are subsonic.
If the graphics that show the technology also represent the real geometry, I doubt there is any real detonation since it is pretty difficult to cause a detonation in a short and small CC.
If there are real detonations occuring, there might be something interesting about this idea.
I have a feeling in my guts (as John says
), meaning I'm not sure it's true what I say here, that a detonation produces relatively less thermal energy (read: heat loss) and more kinetic energy (shockwaves), compared to a deflagration with the same amount of (total) energy release.
So it looks like to me that a significant part of the energy that is normally used to create heat (with deflagrations), is now used to create the supersonic shockwaves. Off course both processes also produce "normal" expansion.
With a piston engine you can't do nothing usefull with those supersonic shockwaves, the pistons are travelling to slow and these waves might even destroy your pistons. The same results we will find with the conventional turbine.
The PDE-turbine looks to me (just) interesting as a first stage
after a CC (that creates less heat!). The PDE-turbine converts then only the shockwaves' kinetic energy into work. A few of these setups are coupled, to create a more constant flow/ expansion (expansion is not done yet after the PDE-turbine), followed by a more conventional turbine that extracts work through expansion.
So let's start building...