Railgun projectiles

[WelshZeCorgi]

Why do some of the projectiles fired from railguns look so... un-aerodynamic? Some look like a miniature square pillar while others look like they stole it from some plumber's tool kit. 

Edited May 5, 2021 by WelshZeCorgi

[razo+r]

Because that is the "sealing" for the projectile in the gun that will get "thrown away" once it left the gun? 

Edited May 5, 2021 by razo+r

[WelshZeCorgi]

18 minutes ago, razo+r said:

Because that is the "sealing" for the projectile in the gun that will get "thrown away" once it left the gun? 

 

Ok, but why are they still squarish? Abram tank guns fire discarding sabot and it's not square. 

[razo+r]

Because the gun of an abrams is round, and a railgun is almost square.

[WelshZeCorgi]

Why did they make the railgun square?

[G.J.S]

20 minutes ago, WelshZeCorgi said:

Why did they make the railgun square?

https://science.howstuffworks.com/rail-gun1.htm

 

[WelshZeCorgi]

So because of the rails? Would shaping the rails to fit a cylindrical projectile not work?

[G.J.S]

2 hours ago, WelshZeCorgi said:

So because of the rails? Would shaping the rails to fit a cylindrical projectile not work?

 

Doubtful. The way the rails work is due to the distance between them - being flat plates then there is no issue. If you use curved plates to go around a round projectile, then some parts of each plate will be closer to the corresponding other plate than other parts of same plate ( o ) <see, the tips are closer to the other tips than the main body of each plate. Inefficient power usage. 

Edited May 5, 2021 by G.J.S

[WelshZeCorgi]

Ah, very good explanation, I see. 

 

Also, would the discovery of room temperature superconductor materials solve the heating issues the railgun projects have, thus finally making railguns able to fire many times before needing to replace the barrel or do superconductors not even have anything to do with railgun mechanics?

Edited May 5, 2021 by WelshZeCorgi

[DmitriKozlowsky]

On 5/5/2021 at 10:22 AM, WelshZeCorgi said:

Why did they make the railgun square?

I wondered about that too. Most of it is classified, but shape of projectile has to do with magnetic fields and magnet guides in the 'barrel' of the weapon, and kinetic effects on target. The projectile travels so fast that it heats up air it is traveling through, and ablates as it itself is heated by friction. A spike shaped projectile would ablate excessively and loose inertial mass, thus reducing its kinetic effect. Inertial (Kinetic) energy = mass * velocity^2. So a thinner projectile would loose mass by shedding molten metal while in flight, thus would have less kinetic energy when impacting the target. There is no explosive in the projectile. All its weapons effects are due to kinetic energy. EM weapons don't have recoil, so a railgun can be used in LEO, where aerodynamic shape of projectile plays no role. EM kinetic , and solid state directed energy (laser) weapons in LEO are being looked at potential counter against hypersonic glide weapons. There may an associated program for ground based Directed Energy Air Defense concept.