Mike,
Nothing I said above was intended as an insult, or to "correct you". My apologies if it came over that way.
Reading your post #8, I agree with everything, but as with most general statements, there are boundaries. Those are best addressed by means of conditional statements. If I am going to pick nits, and there is no need, but you seem to insist; increasing the number of baffles does not always make a muffler quieter:
The obvious limit is if you use up to much expansion volume, then adding baffles may be less effective than fewer. A limit that is reached even sooner than "too much solid volume", is if the baffles are not raked enough for how closely spaced they are; then more air takes a shortcut down the central bore. There is also an effect where long baffle spacing acts to block sound (pressure ripple) more effectively than closely spaced baffles. The effect has analogs in field of view and stand off distance; but that is another topic.
Baffle chambers near the barrel muzzle are supplied higher pressure air, which is then strongly forced to flow radially, and so will work OK with flat baffles, at short intervals. After a number of baffle chambers, the bulk pressure is much lower, and the air has less "radial force", but more forward speed down the bore (as soon as the pellet is out of the way. Expanding the air to a lower pressure and to a larger volume tends to increase its speed towards the exit). Thus, to encourage the faster moving but lower pressure air to run into the "wall", rather than out of the central passage, a longer shallow cone angle adds value. Longer spacing implies fewer baffles. This might make more sense, if one considers that each cone has a high and a low pressure side - as in the front and the rear of the cone.
Getting the air to expand into the divergent cone on the low pressure side is where a shallow cone angle helps. The air flow is basically attaching to and following the wall - even if the bulk pressure is not high enough to keep the air from dethatching from the divergent cone surface. This limitation is unlikely to be reached with the Huben pistol, as that has unusually high muzzle pressure, compared to a 20" barrel .25 Marauder, producing 40 FPE; for example.
like to read your posts. I would rather learn something from you, than try to teach you anything. If the design I posted to the thread links below work better than expected, then maybe someone might ask me to explain how something so conventional looking "works better". If they don't work, please ignore me:
Here, with so few baffles: https://www.airgunnation.com/threads/huben-pistol.1287461/page-38#post-1563702
and
Here, with more baffles; that slant more near the front: https://www.airgunnation.com/threads/huben-pistol.1287461/post-1565565
Peace
Nothing I said above was intended as an insult, or to "correct you". My apologies if it came over that way.
Reading your post #8, I agree with everything, but as with most general statements, there are boundaries. Those are best addressed by means of conditional statements. If I am going to pick nits, and there is no need, but you seem to insist; increasing the number of baffles does not always make a muffler quieter:
The obvious limit is if you use up to much expansion volume, then adding baffles may be less effective than fewer. A limit that is reached even sooner than "too much solid volume", is if the baffles are not raked enough for how closely spaced they are; then more air takes a shortcut down the central bore. There is also an effect where long baffle spacing acts to block sound (pressure ripple) more effectively than closely spaced baffles. The effect has analogs in field of view and stand off distance; but that is another topic.
Baffle chambers near the barrel muzzle are supplied higher pressure air, which is then strongly forced to flow radially, and so will work OK with flat baffles, at short intervals. After a number of baffle chambers, the bulk pressure is much lower, and the air has less "radial force", but more forward speed down the bore (as soon as the pellet is out of the way. Expanding the air to a lower pressure and to a larger volume tends to increase its speed towards the exit). Thus, to encourage the faster moving but lower pressure air to run into the "wall", rather than out of the central passage, a longer shallow cone angle adds value. Longer spacing implies fewer baffles. This might make more sense, if one considers that each cone has a high and a low pressure side - as in the front and the rear of the cone.
Getting the air to expand into the divergent cone on the low pressure side is where a shallow cone angle helps. The air flow is basically attaching to and following the wall - even if the bulk pressure is not high enough to keep the air from dethatching from the divergent cone surface. This limitation is unlikely to be reached with the Huben pistol, as that has unusually high muzzle pressure, compared to a 20" barrel .25 Marauder, producing 40 FPE; for example.
like to read your posts. I would rather learn something from you, than try to teach you anything. If the design I posted to the thread links below work better than expected, then maybe someone might ask me to explain how something so conventional looking "works better". If they don't work, please ignore me:
Here, with so few baffles: https://www.airgunnation.com/threads/huben-pistol.1287461/page-38#post-1563702
and
Here, with more baffles; that slant more near the front: https://www.airgunnation.com/threads/huben-pistol.1287461/post-1565565
Peace
Last edited:
Upvote 0
