Mekugi
09-04-2005, 17:56
EDIT: Please read the whole thread before responding.
[OOC:]With all the new designs for Main Battle Tanks coming out these days and the broadening gap between ETC (Electro-Thermal Cannons) and Conventional guns, I must admit I felt sort of stuck in the middle. While I admire the effect of the ETC gun, the added complexity, weight, and recoil made me more than a bit hesitant to just dive in and accept it as gospel, but to get anywhere near competitive velocities Barrel lengths of conventional guns range neared 65 calibers and above (not exactly ideal either) especially not when tank armor (especially on NS) gets tougher every day.
I must admit my love of research and the exotic got the better of me and I went off to find something to bridge the gap… or at least attempt to. My research sent me down some odd paths everything from Coil and Rail guns (same and worse problems I had with the ETC gun) all the way to Sequential Gas and Ram Accelerator cannons ( Usually one shot and though effective were less than ideal on many levels.) and so I was at a conundrum… no existing designs really seem to fall between the ETC’s awesome power and the reliability and proven ballistic data for a Conventional Cannon.
It was at this point I was struck with what might literally be the most seat of my pants design I have worked on yet.
The idea was simple enough; Create a design that would have a flatter ballistic trajectory, higher velocity, and without having to resort to having to be within barrel length of the target (in short, a shorter barrel) than what would be needed for a conventional gun. After about a day and a half of racking my brain and going through about 8 liters of soda It hit me just when I was about to give up. The ONLY device and mechanical method that had a similar effect with the exception of a shorter barrel, was a Baffle based Suppressor.
Though many people are un aware of it baffle based suppressors are at the mercy of something called “freebore boost’ It is caused by a primary expansion chamber ahead of the barrel's muzzle which acts as a barrel extension as a bullet passes through it. Propellant gases continue to expand inside the chamber and push the bullet through the baffle stack at a slightly increased velocity. Though this Increase is not all that significant in most designs (as its usually discouraged in order to reduce the sound of the firearm) This new design would capitalize on the phenomenon in order to achieve its goal.
Freebore boost may have been the initial spark of the idea but it soon continued much further, as I considered my past research more specifically the Ram Accelerator Cannon that is often used for high speed impact testing at velocities up to 8 km/s but again it’s a very sensitive piece of scientific equipment and not ideal for any field deployment in anyway. The idea from the Ram accelerator that has a base in the new design was that of the Supporting rails that allowed for the gas in front of the round to be pushed to the side as the round passed (this was usually a combustive gas that as it was compressed by the shape of the round ignited in sequence keeping constant pressure on the round during its entire length of travel much like a ram or scramjet engine but only the compressor moved forward instead of the whole engine)
Assuming a similar (but without the complications of isolated combustive gas, and using a modified tank gun) system is used, with only 18 to 36x 2 cm wide parallel rails all along the diameter of the bore to act as a sort of interrupted smoothbore. This would as the bullet travels down the barrel permit the air in front of the bullet to be forced into the recesses by the ogival shape of the bullet compressing the air and pressurizing the recesses behind the bullet. As long as the pressure of the main propulsion remained constant (well call this Pressure +2) it would be higher than the air in the crevices, but as it reached the end of it pressure +2 phase (as the gas expands along the length of the barrel its ability to propel the projectile drops) and reaches the Pressure +1 phase. As the round begins to slow (as happens with almost every cannon out there) the bullet in a normal cannon would begin to decelerate slightly due to friction… but… with the lowered pressure of the main tube in our experimental design the pressurized atmosphere in the crevices are now of equal level with the propellant gas (P+1) and would expand removing the pressure gap and continuing applying a steady pressure all along the bullets path along the barrel ([P+1] + [P+1]= [P+2]). As it reaches the end of the bore a muzzle cap (or crown) will compress the all of the resultant gasses together as they reach the end of the crevices meaning even on exit the bullet receives a constant acceleration as it moves along the barrel, it will also have encountered less friction than a full bored gun due to decreased surface area contact, and have a much more accurate shot with a flatter ballistic trajectory (as can be shown via similar Freebore boost weapons).
I will admit its unorthodox, the standard logic of velocity shows that in order to get more velocity a longer gun that retains as much gas as possible is required (to a point of course). I am also aware that it has its disadvantages (no design is EVER perfect) But if it fills a useful niche I’m happy to have spent the time. I’m not saying this is up for grabs I’m still not 100% as to its validity but it modernly possible (to construct that is) though as for its effectiveness I fully admit I am in WAY over my head.
Advantages of the Enhanced Freebore Pneumatic Effect Cannon (EFPEC) or just Enhanced Freebore Cannon (EFC)-
* Higher velocity over Conventional Guns of similar caliber length
* Flatter trajectory over both ETC and Conventional Guns
* Reduced recoil due to higher mass and slower release of propellant gasses
* Cheaper to mass produce than an ETC Gun
* Can use all current ammuntion usable by conventional smoothbore guns
* Requires no external power sources (other than the normal propellant of the shell)
Disadvantages-
* Weight is higher than a conventional gun of the same size
* Thermal signature is higher, higher level of heat retention
* Barrel fouling may or may not be a problem (no real data to compare as a similar system)
* More expensive than a conventional gun
* Harder to manufacture
Though its not perfect, I think IF the theory is sound it might be a good compromise between the ETC and Conventional Cannons.
Now here is where you come in… COMMENT! Please keeps comments civilized, and on topic. This is not a thread for deciding what is better or if ETC is Modern or Post-Modern, please don’t waste my time and server space. Saying ‘Meh, Mines better…’ will just be ignored… and MOST OF ALL; this is ALL OOC and my intellectual property if I get the green light I will develop and offer such a system IC… but please no ripping my work… it really makes me rather frustrated.
[OOC:]With all the new designs for Main Battle Tanks coming out these days and the broadening gap between ETC (Electro-Thermal Cannons) and Conventional guns, I must admit I felt sort of stuck in the middle. While I admire the effect of the ETC gun, the added complexity, weight, and recoil made me more than a bit hesitant to just dive in and accept it as gospel, but to get anywhere near competitive velocities Barrel lengths of conventional guns range neared 65 calibers and above (not exactly ideal either) especially not when tank armor (especially on NS) gets tougher every day.
I must admit my love of research and the exotic got the better of me and I went off to find something to bridge the gap… or at least attempt to. My research sent me down some odd paths everything from Coil and Rail guns (same and worse problems I had with the ETC gun) all the way to Sequential Gas and Ram Accelerator cannons ( Usually one shot and though effective were less than ideal on many levels.) and so I was at a conundrum… no existing designs really seem to fall between the ETC’s awesome power and the reliability and proven ballistic data for a Conventional Cannon.
It was at this point I was struck with what might literally be the most seat of my pants design I have worked on yet.
The idea was simple enough; Create a design that would have a flatter ballistic trajectory, higher velocity, and without having to resort to having to be within barrel length of the target (in short, a shorter barrel) than what would be needed for a conventional gun. After about a day and a half of racking my brain and going through about 8 liters of soda It hit me just when I was about to give up. The ONLY device and mechanical method that had a similar effect with the exception of a shorter barrel, was a Baffle based Suppressor.
Though many people are un aware of it baffle based suppressors are at the mercy of something called “freebore boost’ It is caused by a primary expansion chamber ahead of the barrel's muzzle which acts as a barrel extension as a bullet passes through it. Propellant gases continue to expand inside the chamber and push the bullet through the baffle stack at a slightly increased velocity. Though this Increase is not all that significant in most designs (as its usually discouraged in order to reduce the sound of the firearm) This new design would capitalize on the phenomenon in order to achieve its goal.
Freebore boost may have been the initial spark of the idea but it soon continued much further, as I considered my past research more specifically the Ram Accelerator Cannon that is often used for high speed impact testing at velocities up to 8 km/s but again it’s a very sensitive piece of scientific equipment and not ideal for any field deployment in anyway. The idea from the Ram accelerator that has a base in the new design was that of the Supporting rails that allowed for the gas in front of the round to be pushed to the side as the round passed (this was usually a combustive gas that as it was compressed by the shape of the round ignited in sequence keeping constant pressure on the round during its entire length of travel much like a ram or scramjet engine but only the compressor moved forward instead of the whole engine)
Assuming a similar (but without the complications of isolated combustive gas, and using a modified tank gun) system is used, with only 18 to 36x 2 cm wide parallel rails all along the diameter of the bore to act as a sort of interrupted smoothbore. This would as the bullet travels down the barrel permit the air in front of the bullet to be forced into the recesses by the ogival shape of the bullet compressing the air and pressurizing the recesses behind the bullet. As long as the pressure of the main propulsion remained constant (well call this Pressure +2) it would be higher than the air in the crevices, but as it reached the end of it pressure +2 phase (as the gas expands along the length of the barrel its ability to propel the projectile drops) and reaches the Pressure +1 phase. As the round begins to slow (as happens with almost every cannon out there) the bullet in a normal cannon would begin to decelerate slightly due to friction… but… with the lowered pressure of the main tube in our experimental design the pressurized atmosphere in the crevices are now of equal level with the propellant gas (P+1) and would expand removing the pressure gap and continuing applying a steady pressure all along the bullets path along the barrel ([P+1] + [P+1]= [P+2]). As it reaches the end of the bore a muzzle cap (or crown) will compress the all of the resultant gasses together as they reach the end of the crevices meaning even on exit the bullet receives a constant acceleration as it moves along the barrel, it will also have encountered less friction than a full bored gun due to decreased surface area contact, and have a much more accurate shot with a flatter ballistic trajectory (as can be shown via similar Freebore boost weapons).
I will admit its unorthodox, the standard logic of velocity shows that in order to get more velocity a longer gun that retains as much gas as possible is required (to a point of course). I am also aware that it has its disadvantages (no design is EVER perfect) But if it fills a useful niche I’m happy to have spent the time. I’m not saying this is up for grabs I’m still not 100% as to its validity but it modernly possible (to construct that is) though as for its effectiveness I fully admit I am in WAY over my head.
Advantages of the Enhanced Freebore Pneumatic Effect Cannon (EFPEC) or just Enhanced Freebore Cannon (EFC)-
* Higher velocity over Conventional Guns of similar caliber length
* Flatter trajectory over both ETC and Conventional Guns
* Reduced recoil due to higher mass and slower release of propellant gasses
* Cheaper to mass produce than an ETC Gun
* Can use all current ammuntion usable by conventional smoothbore guns
* Requires no external power sources (other than the normal propellant of the shell)
Disadvantages-
* Weight is higher than a conventional gun of the same size
* Thermal signature is higher, higher level of heat retention
* Barrel fouling may or may not be a problem (no real data to compare as a similar system)
* More expensive than a conventional gun
* Harder to manufacture
Though its not perfect, I think IF the theory is sound it might be a good compromise between the ETC and Conventional Cannons.
Now here is where you come in… COMMENT! Please keeps comments civilized, and on topic. This is not a thread for deciding what is better or if ETC is Modern or Post-Modern, please don’t waste my time and server space. Saying ‘Meh, Mines better…’ will just be ignored… and MOST OF ALL; this is ALL OOC and my intellectual property if I get the green light I will develop and offer such a system IC… but please no ripping my work… it really makes me rather frustrated.