Singha wrote:can someone tell how the fabled "25 litre chamber" is the current gold std in 155/52 in terms of range vs presumably other smaller chamber?
what chamber is being referred here?
my idea was the shell goes in, followed by the modular cylindrical charges which are also 155mm in diameter and boom.
does 25ltr chamber mean its longer and more charges can be fed in behind the shell to improve the muzzle velocity for longer range?
I would like to believe that given certain parameters, every gun would have a sweet spot in terms of chamber size, pressure achieved and barrel length. Mortars for example give a very high pressure for a very short time and hence the acceleration part of the force ergo pressure gets killed.
You would like to have higher velocity for your projectile for longer with a smoother pressure release, in your Howitzer. Hence compared to a Mortar, Bigger Chamber with sufficient Chamber-Barrel ratio > Better acceleration management > Also longer Barrel length > Bigger gas buildup before the projectile has traveled enough in a slower manner > Ability to push for longer distance (meters) in a smoother fashion probably even for smaller times if a fast burn is achieved > thus giving higher yet smoother initial acceleration for projectile in side the barrel > Higher force for same size of shell base for longer > Fuller buildup of pressure for the whole Chamber-Barrel system.
See the figures in this
http://publications.drdo.gov.in/ojs/ind ... /2281/1237. Mujhe bhi sirf pictures hi samaj mein aati hain.
So yes if they say 25 ltr is gold standard then i guess it is.
Singha wrote:also what is the usefulness of a muzzle velocity radar? does it give the exact speed of shell and hence builds up a data bank of {speed,barrel elevation,charges} that is more accurate than static tables provided by the OEM or army test center.....deviation as barrel wears etc?
unlike hitting a jihadi with a stick, artillery esp this massed coordinated fire thing seems like a highly technical field needing lots of math calculated in real time by the control systems.
I think that is why they have the muzzle velocity radar fashioned in the way it is for Dhanush. But I wonder how important that really is. There still is no way of understanding properly the atmosphere. Even if you are able to measure not just the exit velocity but also the downrange velocity, you still have to contend with the velocity changes after highest point which is still going to be ruled by Pawan Deva. The older styles of velocity measurements could have been automated too (or so I guess). Besides how would a battery with all 6 howitzers having the MVR fare against 5 dumb and 1 MVR battery. I guess the cost is not so big a factor hence the wish list of MVR on every gun.
Shayed jaroori hoga.