increasing vs decreasing space between cones

[Capt. Link.]

Interesting :

FRP has been discussed many times before. I have the theory that its a dieseling effect.Lack of oxygen either by displacement or lower combustion gas temperature or pressure always result in eliminating or reducing it.Ablatives and inert gases prove this.Initial chamber pressure and size of chamber are interrelated. This has been seen/heard by switching between a rifle and pistol with the same suppressor & ammo.Controlled detonation to starve combustion gases of available fuel is a technique used in several industries including suppressors.Small initial chambers that use ports like Dater Holes and other gas flow enhancement cause better suppression and less FRP by using this tech.

I ran experiments many years ago using what I called reverse spaced baffles.Chambers started small and increased in volume towards the muzzle.This works well but you must increase the aggressiveness of each baffle in turn to capture lower & lower pressure gases unless length and number of stages is not a factor .Each chamber becomes tuned and the variations are extensive.I do believe that its a viable technique but it requires more research. The more common small initial chambers w/ decreased spacing helps keep the pressure higher and results in better losses for each stage.

Getting the most out of a design:
Thread interior of suppressor & baffles to allow adjustment of placement & chamber size.Make your porting adjustable to tune gas flow.This can be done and meet all form 1 requirements.

-CL

[Obiwanbonjovi]

combustion does deplete the oxygen.

But remember, oxygen is flammable and is a necessary part of combustion.

Oxygen is not flammable, but does make everything else burn hotter and faster, an important distinction.

After the first round, the gasses in the can are not immediately replaced by atmospheric air, but have simply dropped to atmospheric pressure, it is still an extremely low oxygen atmosphere inside the can

The mushroom effect is simply the gasses expanding in all directions to fill the container they are in(in this case either the inside of can, or the atmosphere for non suppressed gunshots), the reason it doesnt happen immediately at the muzzle is simply die to the inertia of the high velocity gasses, if the bullet and gasses were stationary and the firearm was moving away from them the omnidirectional expansion would occur immediately at the muzzle. Due to the low mass of the gasses it does not take much time or distance for the air resistance to overcome the inertia. This is the same thing that causes the hot spot in the suppressor to be several inches from the muzzle, the inertia of the gasses keeps them moving to that point quickly, at which point the baffles keep them there as long as possible, and in subsequent chambers the gasses have cooled enough that the rest of can does not get as hot.

Although there are far too many variables involved to give a definitive answer, it would seem to me that progressively smaller chambers would be an improvement on progressively larger, as the lower the pressure gets the less velocity the gasses have when entering a new chamber. The entrance to each chamber is similar to the muzzle with the gasses escaping the previous chambers at a specific speed based on pressure and hole size, upon entering each chamber the gasses are propelled along the bore line with a certain amount of inertia, this inertia will make the gasses tend to continue the path down the bore rather than expand omnidirectionally and fill the chamber. Each chamber should be long enough to allow the gasses to lose inertia and fully "mushroom" and since the pressure is lower at each subsequent chamber the gasses have less velocity/inertia and therefore do not need as much length per chamber to obtain full "mushtooming".

Sorry if this isnt clear, it makes more sense in my head than it does on paper