Nozzle Design Questions

[Fredd3039]

This is a Muzzle Brake for a rifle barrel that uses rocket nozzle type porting that reduces felt recoil. The "Nozzles" are machined at a 30 deg slant towards the rear. The explosive pressure behind the bullet gets vented into the nozzles as the bullet passes them. The nozzle venting seriously dampens the recoil effect. I guess my question would be, Since this is drilled into a metal rifle barrel with a hollow core, the 30 deg angle reduces some of the throat volume or area, does this effect the function of the nozzle in a negative way? Oh I am an absolute beginner with Nozzle design so please go easy on me.
Thanks

 

[Baluncore]

Oh I am an absolute beginner with Nozzle design so please go easy on me.

Comments.

Drilling those diagonal nozzle holes will be difficult and expensive. The differences in machining and metallurgy, between a barrel and a brake, suggest it would be easier to make the brake separately, then attach it to the end of the barrel.

Very little gas will change direction, to escape backwards. I expect those small diameter holes will draw in more air, than they vent gas. There needs to be a reflector step internally to direct the propellent gas, backwards through the jets.

Better to have several axial discs with holes, like flat or conical washers. The projectile passes cleanly through the hole, while most of the gas pushes on the annulus, pulling the barrel forwards, countering the recoil. Gas that remains in the cavities between washers, may be released backwards through ports.

It is important that the operator not be blinded by the backward jets, and that dust is not raised from the ground when operating prone, that could make the operation dangerous to the operator.

 

[berkeman]

and that dust is not raised from the ground when operating prone, that could make the operation dangerous to the operator.

Interesting point. I did not know that.

 

[Fredd3039]

This may illustrate my question better, which design would produce more thrust A or B. Note the throats of each. At a 30 deg. slant the throat can either be straight inline with the nozzle As in the A example or an actual throat like in the B example.

 

[Fredd3039]

Forget that this has anything to do with a firearm and consider my question as if this was all the knowledge you have to go on: If a Nozzle Tilt of 30 deg. is necessary, which design would produce more thrust A or B. Note the throats of each.

 

[Baluncore]

I guess by combustion chamber you mean barrel, and the bullet travels from left to right. Your A has a small reflective corner, while your B has larger ports. Neither is optimum. Propellant combustion should have completed before reaching the muzzle brake. I believe what you are thinking of is called a ported-barrel, but is being used as a muzzle brake.

The brake cannot be machined into the barrel, because the ports will either be too small to operate, or be so large that they weaken the barrel. You really need to separate the brake from the barrel.

Take a look at the schematic of various forms of muzzle brakes: https://en.wikipedia.org/wiki/Muzzle_brake
Your concept is like Fig. a2 as it has backward holes.
Fig. b1 would be quieter, while Fig. b2 would make a better brake.