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MrDeaf

Who wants to play with ballistics that everyone loves talking about?

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Part 1.

Okay, so I found a ballistic trajectory program that seems to do the job well enough, but I am having trouble calibrating the missing data, such as cross-sectional area and drag coefficient, to achieve results similar to what is given in navweaps.com.

 

So, what I would like is, with the help of everyone who is interested, to give numbers they think will achieve similar results.

Do note, that, although navweaps is suggesting hard data, there can be some margins of error with shell velocity, etc. because we are dealing with WW2 era naval guns that used gun powder, which never burned at ideal rates.

 

Video of program:

Program itself: https://www.dropbox.com/s/fd1usie6py0qmse/Drag%20Simulator%20for%20Java%201.7.jar

Weapon data: http://www.navweaps.com/Weapons/index_weapons.htm

 

Part 2.

Let's compile this data together and see what sorts of ballistics we are actually dealing with, and not just what we see in the game.

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reserved.

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The data for Cd is in the game files, ask IKU19 he has it all, for the cross section area you can get away with using the diameter of the shell and using it to find the area of a circle. 

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lots of ballistic coefficient programs, but none to my knowledge that will calculate the profile/weight/density of naval projectiles.

If you have the weight in grains, along w/distance, point of impact w/line of sight....you can roughly come to a standard deviation of velocity and  Coriolis Effect

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lots of ballistic coefficient programs, but none to my knowledge that will calculate the profile/weight/density of naval projectiles.

If you have the weight in grains, along w/distance, point of impact w/line of sight....you can roughly come to a standard deviation of velocity and  Coriolis Effect

 

That might explain the deviation in range I get with the historical ranges, compared to what this calculator puts out.

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IKU19 hasn't gotten back to me, so this is, very roughly, what I have gotten.

I don't have good ranging data for other guns, so they are incomplete.

 

 

Muzzle velocity

(mps)

Shell Mass

(kg)

Darg coefficient

approximate

cross-sectional area

(m^2)

 
USN 127mm/38 792 24 0.344 0.013  
USN 152mm/47 762 59 0.302 0.018  
USN 203mm/55 823 118 0.284 0.032  

USN 203mm/55

SHS

762 152 0.315 0.032  
IJN 100mm/65 1000 13   0.008  
IJN 127mm/50 915 23 0.360 0.013  
IJN 155mm/60 920 55.87 0.310 0.019  
IJN 203mm/50 840 125.85 0.252 0.032  
KM 150mm/60 960 45.5 0.299 0.018  
KM 203mm/60 925 122 0.251 0.032  
VMF 130mm/50       0.013  
VMF 152mm 950 55   0.018  
VMF 180mm 920 97.5   0.025  
VMF 220mm 985 176   0.038  

 


What sorts of graphs would people like?

Normalized for range, or launch angle?

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IKU19 hasn't gotten back to me, so this is, very roughly, what I have gotten.

I don't have good ranging data for other guns, so they are incomplete.

 

 

Muzzle velocity

(mps)

Shell Mass

(kg)

Darg coefficient

approximate

cross-sectional area

(m^2)

 
USN 127mm/38 792 24 0.344 0.013  
USN 152mm/47 762 59 0.302 0.018  
USN 203mm/55 823 118 0.284 0.032  

USN 203mm/55

SHS

762 152 0.315 0.032  
IJN 100mm/65 1000 13   0.008  
IJN 127mm/50 915 23 0.360 0.013  
IJN 155mm/60 920 55.87 0.310 0.019  
IJN 203mm/50 840 125.85 0.252 0.032  
KM 150mm/60 960 45.5 0.299 0.018  
KM 203mm/60 925 122 0.251 0.032  
VMF 130mm/50       0.013  
VMF 152mm 950 55   0.018  
VMF 180mm 920 97.5   0.025  
VMF 220mm 985 176   0.038  

 

 

What sorts of graphs would people like?

Normalized for range, or launch angle?

 

I'd have to vote range honestly. 

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Anyone still install java in their computer?

Edited by Cruiser_Haguro

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Anyone still install java in their computer?

 

Those that program for Android need it.

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