I have a 5.56 stamp and keep going back and forth between filling a can with traditional cones/spacing in the proven layout, or using the almost flat, perforated dual blast baffle and a couple 60s like the turbo k.  I can make virtually any baffle shape, size, I just can't make multiples and experiment :-(
What would Arf do?
Thanks

Marked for interest.

I have been looking into this for my second stamp. (Hopefully this summer)

If I remember correctly, someone did mention that their testing did not conclude enough difference to put that (blast plate?) with holes drilled into before the first cone. I tried reading into it more myself. The few things that I did comes up with is that it helped with back pressure. Fundamentally it does make sense. I can not provide any personal experience. Unfortunately my physics classes this year do not pertain to stuff like this, (maybe thermodynamics) so my peon knowledge doesnt make much of a difference either.
There is a good video on youtube of someone putting a bore camera down one to give a good view. Maybe start there?

What a lot of people fail to remember is they're not "silencers", they're suppressors. They're main focus isn't always dB's. They can also be used to suppress: back-pressure, flash, recoil, and the tendency to increase cyclic rate.

This being so, the features contained w/in aren't always geared, directly, to dB reduction. Yet, they're designed and arranged in a specific configuration to meet the parameters set by the project's goals.

If you like it so much, watch the bore scope vids and make a clone.

I would think one thing that may help is using a larger 1.625 can or even 1.75 OD can but keep the same length as the Turbo k. Then just use 60 degree cones.

I just had ECCO make me up a 5" model.  We'll see how it compares

Yuppers, the fine line between FRP and back pressure.  Maybe the holes act like a spark arrestor and prevent secondary ignition or something?  I have no clue...



Dang guy, I know I am an idiot with this stuff, but I really was curious on the "why" the flat, perforated baffle works; high to low pressure, jetting to disrupt flow, etc....  



I got ya fam:

Attached File


Guess I will start with four small holes, and then try six, then increases the size until performance "erodes"  ha ha.  Oh well it is only $200 and some stainless.

So I have still been looking into this. I came alone with something else that struck me in an odd way.

The M4 2000 is regarded as a well done 5.56 can. The M42k uses a flat plate (not sure if it is drilled or not) for the initial blast baffle. It then uses only 2 cones of some sort after that. If YHM did somewhat mimic the M42k, than it is fairly close with the exception of an extra baffle. The turbo and turbo K are well like through the community.

He is my initial though about when I get my stamp back and am able to send it off to nick. (Unless he stops taking orders, then I am on my own) If I make a flat or slight degree blast baffle with hole, line a 17-4 baffle in front of it, that should be set 1. Spacer that is around .75 and another cone. Spacer that pushes the last cone right to the edge of the cap, or a small stack of 2 cones at the end.

ROUGH math breakdown.  space in maverick phoenix = 3.52.  Plate maybe 1/8th inch? cone with .58 skirt, .75 spacer, cone with .58 skirt, .5 or .6 spacer (.75 if I only use one cone at the end) and a last .58 cone (or two and I will shave the skirt on both cones to fill the last gap.

I know I should do a drawing. Sorry. Just thinking out loud here.

In the combustion field, it's known as a diffusion baffle/plate/wall. Its purpose is to get the combustion envelope to mix and complete, sooner. This allows the gas, and subsequent heat, to be worked by the baffles, more efficiently.

Just do what I am doing. Contact Nick. I was starting to wonder if I could do this all myself, but why not trust the guy who has his own thread?

Thanks!  



Too late, already sacrificed some gr 5 ti bar to the chip gods.  Kinda excited to see how this one performs...

Thermo isn’t going to help much. I am taking it now.

Not nearly as much as Combustion Science.

Honestly, between NFATalk and SilencerTalk, there's enough info to get caught-up on decades of silencer tech. Start at the oldest threads and work forward. Should take as long as any engineering semester ;)

Thermo 1, 2, or heat transfer inst going to help much either. You'd have to take some graduate level fluid/gas dynamics classes to get into material that pertains to this.

Computer modeling of fluid flow and mixing in partially obstructed pipes is junior year chemical engineering curriculum, as part of designing packed bed reactors. While they don't cover a big chunk of something solid at the front of the pressure wave, it wouldn't have been that much of a stretch for the software (for which I can't remember the name). But at the outrageous prices per seat such software costs, and since combusting gases don't follow gas laws all that well, Matlab and just trying a ton of different designs is probably the way to go.

Kharn

Yep, I remember, CHEN undergrad here.

I know what software you're talking about but can't remember the name either My numerical analysis prof showed us some stuff with it, but we did all of our heat transfer modeling in Matlab.

I highly doubt any undergrad would be proficient enough in Matlab to come anywhere close to correctly modeling a suppressor though. I know I couldn't.

There was a big thread of suppressor modeling videos (in some other language if I'm remembering correctly) somewhere. Maybe it was on Rusty's old form1 board?

I use ANSYS, for CFD of industrial combustion systems, all the time. It took me a long time to get something even remotely close to what I theorised the internal environment of a suppressor to be. And I've been making suppressors for around a decade. Impulse flows are unpredictable and the specific media of these fluids is not easily modeled. Results can be wildly inconsistent and I have no way to correlate them with dB reduction. Yes, you can record exit pressure and velocity, but, again, I have no access to metering equipment.

This being said, I have found constant flow modeling of specific features or singular designs to be helpful. They seem to match with proven designs.

As I said above, the NFA forums are an unprecedented wealth of information. Without them, you'd be where Maxim was, at the turn of the century.

I did not know some nerd talk would be so accepted around here. Unfortunately I am not fond of the physics and math dept at my school. Right now I am finishing up Diff Eq, and this is my last math class since I took Linear Algebra before it.

Maybe Emag physics will be better than Kinematics!