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greenlight
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Nux is the charge weight the same as the last CSC?
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nux vomica
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5 grams same as the last one the angle former gave 6 mm extra hight.i am setting it up for a test right now.
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greenlight
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Nice, what was the total explosive height?
Post results when u can
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nux vomica
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Results are in no penertration, got a nice looking straight hole over 2.5mmin dia can get a 1.6 mm rod to 29 mm deep in the hole, will have to do test
again now 
  
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greenlight
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Looks like a much cleaner hole this time though!
Hmmm, I think the variables affecting the penetration problem would have to be standoff or explosive weight/height. I will have further look through
some papers.
Did the last CSC test you did make it 29mm through the plate as well?
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nux vomica
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Cant tell on the first one cause the carrot is blocking the hole but the bulge on the back is the same.
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gnitseretni
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Make a cone out of thinner copper sheet. I think that will improve results if everything else is kept the same.
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ecos
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I am not sure but if you would have smaller angle cone this will improve it.
Going from 60 degree to 45 or 30 degree cone angle would be better!
[Edited on 23-8-2015 by ecos]
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greenlight
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60 degrees is about the optimum angle for CSC's.
I have read on here somewhere:
When the cone angle is smaller, the velocity of the jet is higher but its mass becomes much smaller.
When the cone angle is larger, the jet velocity decreases, but slug/carrot velocity increases.
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nux vomica
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I am making a new batch of etn plastic with higher sg hopfully that will make a difference nuxy
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greenlight
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What do you mean by the abbreviation sg?
Forgive me if its something obvious.
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ecos
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i think he mean specific gravity but not sure , just guessing
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greenlight
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Yeah I was thinking that too, he must mean higher density plastic.
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nux vomica
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Sorry I should have said grams per cc
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greenlight
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I went through the document optimized conical shaped charges and photographed a couple of tables that may have answers to some of the problems that
have been arising with the CSC's. The document studys cone angle/diameter, standoff, explosive height/width, liner material/thickness, and explosive
type and tamper.
The first table is different cone angle's and standoff's and their effects.
The second is jet penetration effects from varying explosive height.
The third is a diagram of the final results from all test's incorporated into making a perfect conical shaped charge.
[Edited on 23-8-2015 by greenlight]
[Edited on 23-8-2015 by greenlight]
 
It seems I was wrong and Ecos was right and the optimum cone angle is 45 degrees with 60 degrees still being effective but any more angle and the
penetration starts to drop off.
So the optimum CSC configuration seems to be:
Cone apex angle 45 Degrees
Liner thickness 0.01 CD (1% cone diameter)
Explosive height 1.5 -2 CD
Explosive width 1-1.4 D
Optimum standoff 2-6 CD
[Edited on 23-8-2015 by greenlight]
[Edited on 23-8-2015 by greenlight]
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nux vomica
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Thanks Greenlight for the great info, nuxy.
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ecos
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Per my undersraning, if metal powder like fe2o3 is added. This would improve the propagation wave inside the EM. 1% would be enough.
According to parameters of greenlight we expect around 5 cm penetration. Good luck nex vomica
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nux vomica
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I drew the improvements you posted greenlight into a new shaped charge design thoughts?
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ecos
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You shouldnt insert the whole detonater inside the explosive. Just 1/3 detonator length should be in.
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greenlight
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Nux, that looks very good
Cone angle = 45 good
Liner thickness = 1%CD good
Explosive height = 2×CD good
The shape of the charge casing and the extra head height should nake for nice detonation wave formation.
[Edited on 23-8-2015 by greenlight]
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gnitseretni
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I don't think you have enough head height there but I hope I'm wrong. The smaller the angle the more force is needed to collapse the cone, so you're
expending more energy into collapsing the cone by decreasing the angle and with such a small charge I'm afraid there won't be enough energy left for
deep penetration. Again, I hope you'll prove me wrong.
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greenlight
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Hmmm, i will try and find some documents with head height tests in them and see.
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greenlight
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I can only find tests on explosive height not actual head height even though they are nearly the same (increase in explosive height=increase in head
height) but after looking at a lot of shaped charge diagrams, a lot of them have about the same head height as Nux's, like the diagram I posted
yesterday.
If I am correct, it is still going to be the about the same force, but the higher the head height, the flatter and more planar and well developed (to
a certain point) the detonation wave gets before it interacts with the liner.
Optimizing shaped conical charges document says this:
"Using a liner apex angle of 45 degrees and a liner thickness of O.OlD, the explosive height (H) was varied between O.5D and 3D. The jet penetration
increases as the explosive height increases, however, there is no significant increase in jet penetration for explosive heights greater than about
1.5D. Therefore, a value for H of 1.5D to 2D appears to be sufficient."
Your diagram is at 2xCD explosive height Nux and the document reported no improvement from there on, even testing up to 3xCD.
You could always make two identical CSC's, but vary the head/exploive height on them to see what works best for your size charge because the CSC's in
those tests are 9.8cm in diameter compared to your 1.5.
[Edited on 23-8-2015 by greenlight]
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nux vomica
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I need to find some 0.16 copper first but the caseing wont be a problem , I will try the drawing dimensions first time around, thanks Greenlight
nuxy
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ecos
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Hi All,
I think making concave metal hemisphere shaped charge is much easier than a cone. check figure below.
The cone should be symmetric , apex should be in the center, .....etc , this makes cone design a real challenge
Most of the videos I saw and papers I read prefer cone ! , What I know that a cone would have deeper penetration distance and the hemisphere would
have wider hole in the target.
is there any other preferences for using cone rather than hemisphere ?
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