? In my half Century in unorthodox propulsion I have followed a
path contrary to advices of experts, not cared much about the state of
art. This allowed me to avoid many mistakes reputable Companies and
innumerable amateurs make.
One of the confusions relate to difference between ordinary pulse
jet and DWPE.
It is the same difference as between stock car and formula 1
racing car.
Second myth is that resonant pulse jet is somehow better than
other jets. Relatively only, when compared to haphazard jets.
Resonance involves waves which take away power, even as it is true
that in pulse jets of any kind the power is interrupted. Detonation
frequency is of utmost importance and compensates generously for
inadequacy of the design We can see technically inferior modeller’ jets
having high efficiency precisely for this reason. Small engine naturally
has high frequency, basically because filling the chamber is quick.
Many people cannot learn from SNECMA Escopette engines’ example. .
Nobody seems to ask question why the French used six engines to
power a glider instead one in middle or two on sides.
Another myth taught by Institutions of learning is that range of
speed in pulse jet is between Mach 0.5 to Mach 3.0,
It shows that imagination and designer instinct is conversely
related to amount of money available for research. I would put limit,
according to my present experiences, to Mach Thirty. All necessary is
to follow laws of physics, have open mind and not repeat mistakes of
others.
Top of the line detonation wave engine’s qualities are in the
name. It operates using detonations. not conflagrations.
In such engine the detonation must be initiated at the front wall,
be short, violent and discrete, not connected to previous one. This
avoids the unacceptable Kadenacy effect, provided the intake cross-
section is sufficient, not creating strong negative pressure to draw
exiting gases back. In hot engine, it cannot be prevented that the fuel
mixture is ignited on all sides. The front ignition must be more intense
and because of second condition of the mixture volume length not
exceeding its diameter this effect is minimal. In over-filled chamber
there are reflection waves causing low efficiency and waste of fuel .
Conflagration is slow process.
It is obvious that difference between ordinary pulse jet and DWPE
is in organisation of the function. Your GRANDDAD
www.philonline.com.ph/~eron2

I do not see how the propagation of a combustion driven SHOCK wave of the PDE can be considered to have more finesse than a combustion driven resonant acoustic mode used in the pulsejet. Your choice of words does not accurately reflect the physical mechanisms behind the operation of each propulsion system.