Ambient Pressure/Ram Pressure Intake conditions

[dmjc66]

Hi.
Ive been looking at the MULTIPULSE central heating units. Theyre valveless but theyre also unlike a valveless in the respect that theres no finite intake length, and they breathe gas; its not injected etc.

Link kindly supplied me by WEBPILOT:
http://www.google.com/url?q=http://www. ... 3GhSkNOv_w

Im assuming these boilers are resonant, just as per pulsejet.
The 'Spherical' combustor has '2' tailpipes, of equal length.

Since pressurised intake conditions must attenuate sound traveling forward am I right in thinking the 2nd chamber in front of the combustor is replacing the usual intake?

Also Im reasoning from the above the tune of the boiler is dependent on the pressure of the gas.

Perhaps someone could walk me through the basic requirements of pressurised intake/ram air valveless pulsejets just where they are at variance with the ones operating and particularly starting up at broadly atmospheric pressures?

Does 'intake pressure' for instance replace the tuning effects of 'intake length' at a given diameter?
(which might explain why too much starting air on certain pulsejets wont incite resonance)

Dave