home bbs files messages ]

Forums before death by AOL, social media and spammers... "We can't have nice things"

   rec.arts.sf.science      Real and speculative aspects of SF scien      45,986 messages   

[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]

   Message 44,896 of 45,986   
   alien8752@gmail.com to MrAnderson   
   Re: Coilgun projectile velocities in spa   
   19 Mar 17 21:46:19   
   
   From: nuny@bid.nes   
      
   On Sunday, March 19, 2017 at 6:26:50 AM UTC-7, MrAnderson wrote:   
   > This plasma spike seems interesting, I am surprised I didn't see this yet. Do   
   > I understand it correctly? This plasma torch creates plasma shockwave and   
   this   
   > shockwave acts as a shield?   
      
     Yep, the plasma is generated with focused microwaves and acts like an   
   ablative shield as long as it's maintained. The accompanying textsuggests   
   other possibilities:   
      
     "Our experiments have demonstrated that operating an electromagnet inside a   
   re-entry model causes the shock wave ahead of the model to be pushed away from   
   the body at a steeper angle. Clearly the magnet influences the flow field. It   
   is not difficult to    
   imagine that a magnet three dimensionally gimballed could be used to modify   
   the flow field in any desired way and to vary the lift and drag upon command."   
      
    So a strong magnet in the nose cone of an atmospheric entry vehicle (Rod From   
   God) only needs a fricking magnet to keep from burning up?   
      
     Okay, can *small* hypersonic projectiles carry a neodymium magnet strong   
   enough to do the job?   
      
     How will that affect its mechanical properties upon impact?   
      
     Suppose the darts are made of technomagic high temperature superconducting   
   iridium/holmium/neodymium alloy that is denser than and as strong as tungsten   
   but can "steal" some energy from the coilgun to magnetize itself as it's being   
   fired?   
      
     Would that negatively impact its usability for ship-to-ship use?   
      
     Wait- I read further down:   
      
     "A large magnetic field could produce hydromagnetic drag in the cloud of   
   ionized air the vehicle produces as it enters the atmosphere. With   
   hydromagnetic braking the kinetic energy of the vehicle would be absorbed   
   through the magnetic field rather than    
   through heating of the vehicle itself, with the result that the total weight   
   required to protect the vehicle from overheating and destruction could be   
   markedly reduced."   
      
     Damn. Can the magnetic field shape, and therefore the shock cone shape be   
   twiddled to minimize drag? Somehow "sharpen" it instead of having it be blunt?   
      
      
     Mark L. Fergerson   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]


(c) 1994,  bbs@darkrealms.ca