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greenlight
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I looked up the warhead explosive weight quickly and it seems the front shaped charge is 7 kg and the one behind is 10 kg so more than enough to turn
the cone into a jet.
The thing between the cone and the detonator in the second picture is a wave shaper for the detonation wave and would increase the performance
further.
I think the 1200mm penetration is axheivable with these amounts of explosives. Earlier in this thread I posted a photo of two 30 gram SC's with
quite surprising penetration for their size.
The first explosion would detonate fractions of a second before the second and it would be such a small time difference thats it wouldn't affect the
performance of the latter charge.
Be good, otherwise be good at it 
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ecos
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@Greenlight, I think you are mistaken
the Warhead weight is 7 kg HEAT or 10 kg not the shaped charge weight. Ref : Wiki
if the warhead is 7 kg. this will include explosive , copper cones, propellant(for 5Km) , sensors , fins, outer frame, controllers , detonator , ...
etc
I believe the max weight of the first SC will be in range of 200g and the second one in range of 1 Kg.
you state the full process will take a fraction of a second between the first and second shaped charge. a fraction of a second is very large since VoD
of EM are in range of 7000 m/s. in a fraction of a second many things had changed !
[Edited on 28-12-2015 by ecos]
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greenlight
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I found this also:
http://www.military-today.com/missiles/kornet_t.htm
It says total missile weight is 27 kg and warhead (explosive) weight is 7 and 10 kg.
It is quite hard to find accurate information on it.
Also, yes, I realize what I said sounded a little stupid when talking about energetic materials which detonate at thousandths of a second
I am unsure how the front detonation does not affect or damage the initiation system for the rear shaped charge as I just remembered a video on
Youtube of a Carl Gustav warhead penetrating a brick wall with the first charge, flying through this hole and detonating the secondary charge on the
other side.
I will look into it as I am interested in finding out now as well.
Be good, otherwise be good at it
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ecos
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yes, it sounds interesting.
I understand from your webpage that , 27 Kg is the weight of launcher + warhead and the 7kg or 10kg are the warhead's weight.
27 kg is too much for a warhead.
I checked the penetration power of Panzerschreck. It has 700 gm of EM (60% RDX and 40% TNT) and it can penetrate 21 cm of steel.
so it is still strange for me the superior power of Kornet-E (1200 mm ) !!!! 
[Edited on 28-12-2015 by ecos]
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Fulmen
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There are several reasons for the difference in performance. For one the Kornet is 152mm while the Panzerschreck is only 88mm. In addition there is
more than 50 years between these two, modern CFD has increased our understanding of these devices significantly. Comparing these two directly is like
comparing a 1940's car engine to a modern one.
[Edited on 28-12-15 by Fulmen]
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ecos
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@Fulmen, The technology of cars has changed a lot specially the design of motors and safety but the SC didn't change this much. Most of the effort was
consumed in understanding how it works. I also believe most of the new changes was to improve the penetration power but most of the improvements has
minor effects.
The concept in SC is EM and copper cone. most of the studies were about the suitable EM and different cones shapes or materials but the concept is the
same !
Panzerschreck --> 700 g penetrates 21 cms.
Korent = ? g penetrates 120 cm
therefore , Power of Kornet-E = 5.7 power of Panzerschreck
If we assume linear equation this means the SC of Kornet should be 5.7 times the size/weight of Panzerschreck = 5.7 * 700g = 4 Kg of EM
if the warhead is 10 kg (4Kg for shaped charges , 6 kg for propallent , frame , fins, ...) this would make sense for me
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Fulmen
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I don't think you fully understand how much work has gone into SC's since it's discovery. And just look at this thread, how hard isn't to make a
reliable, high-performing charge?
We're not banging rocks together here. We know how to put a man back together.
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ecos
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I am not expert as many here but i noticed the bad performance of the SC is due to the copper cone design and the alignment of the casing with cone
and detonator.
Maybe you are right. I still have many things to learn !
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greenlight
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Also, the Panzerschrek only has one shaped charge and probably a less powerful explosive than what we have nowadays (TNT-based compared to HMX and
other more powerful EM-based main charges). Another webpage I found says the Kornet missile is 27 kg and is 29 kg including launcher tube.
It is bigger, better explosive, more explosive and also has a waveshaper in the secondary charge which would increase penetration.
I have been looking at illustrations of tandem charge warheads and it seems the the first charge is always smaller than the main secondary charge.
There is also always a considerable empty gap and sealed off section separating the two charges that the flight electronics is placed in on some
missile designs. I can think of two ways the tandem charges are set off without damage to the second main charge:
1: Since the charges are detonated from the top and the detonation wave is propagating downward and to the sides more than back, maybe this gap stops
the explosion damaging the secondary charge. If the flight electronics is placed in this gap between the two charges, that can get damaged and could
act as a barrier getting destroyed before the second shaped charge gets initiated as it would no longer be needed as the missile is no longer in
flight.
2: Either that or since only a fraction of a second is needed before initiating the second charge so the jet can follow the first charge's path, the
explosive gases don't have time to reach the second charge and damage it before it is initiated.
Be good, otherwise be good at it
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ecos
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REF : http://www.deagel.com/Surface-to-Air-Missiles/9M133FM-3_a002...
it is stated in many sites the weight of the warhead is 7 Kg and the warhead + container = 29 Kg
It would be very heavy if the warhead only is over 25 Kg !!
Of course two warheads in Kornet-E is better than one warhead and the size is also bigger so it delivers more power.
I like the first assumption, The first SC is small enough to break reactive armor and the explosion power should be controlled not to affect the
second shaped charge. The second SC should should work before the first explosion affect it.
if Kornet-E use very powerful EM like HMX, the effect of the first SC (Heat, Pressure, ..) would be very hard to be controlled. This is a real
challange!
Maybe both SCs are fired in the same time !
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PHILOU Zrealone
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Quote: Originally posted by ecos  | @Fulmen, The technology of cars has changed a lot specially the design of motors and safety but the SC didn't change this much. Most of the effort was
consumed in understanding how it works. I also believe most of the new changes was to improve the penetration power but most of the improvements has
minor effects.
The concept in SC is EM and copper cone. most of the studies were about the suitable EM and different cones shapes or materials but the concept is the
same !
Panzerschreck --> 700 g penetrates 21 cms.
Korent = ? g penetrates 120 cm
therefore , Power of Kornet-E = 5.7 power of Panzerschreck
If we assume linear equation this means the SC of Kornet should be 5.7 times the size/weight of Panzerschreck = 5.7 * 700g = 4 Kg of EM
if the warhead is 10 kg (4Kg for shaped charges , 6 kg for propallent , frame , fins, ...) this would make sense for me |
For a given explosive, the increase of explosion power is quadratic as a function of weight, not linear!
EP = A*(weight)²
A being a constant dependant of the geometry of the explosive charge, density of it and of the explosive itself...
This effect is obvious when plotting lead block test expansion as a function of weight of explosive for various explosives...
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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nitro-genes
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What is the charge diameter of both the warheads? Weight says little, assuming that the newer launchers and warheads are likely made of super light
modern composites, allowing for larger charge diameters while maintaining a portable weight. Even a precisely constructed 60 deg C copper cone, driven
by a modern high VoD PBX can reach 9 CD's of penetration. Use of computer modelling and wave shapers can maintain jet tip velocities, while bringing
down the weight of explosive needed, further allowing more weight effective shaped charges. Using DU or molybdenum liners can up the penetration depth
to 11 or 12 CD. This would mean that the komet warhead diameter would only need to be around 100 -120 mm in diameter for 1200 mm of penetration.
For tandem shaped charges, I could imagine that even a tiny axis offfset between the two would be enough for both jets to form undisturbed.
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Fulmen
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Philou: While that is true it's not relevant to shaped charges. Beyond a certain level more explosives has little impact on the performance, so trying
to calculate the charge from it's performance alone is impossible.
We're not banging rocks together here. We know how to put a man back together.
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careysub
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| Quote: Originally posted by PHILOU Zrealone |
For a given explosive, the increase of explosion power is quadratic as a function of weight, not linear!
EP = A*(weight)²
A being a constant dependant of the geometry of the explosive charge, density of it and of the explosive itself...
This effect is obvious when plotting lead block test expansion as a function of weight of explosive for various explosives... |
Assuming the stated lead block test results are as you say (I have not tried to check - I would appreciate a link if you have one), then this is true
only if "explosion power" is a term defined by the lead block test results, which out of necessity only deals with small amounts of
explosives.
Under such conditions non-linear effects with energy dissipation mechanisms, edge effects, detonation build-up, material yield properties, etc. are
quite plausible.
With the advent of sophisticated numerical modeling techniques for explosives, and much more detailed understanding of the fundamental thermodynamic
and other physical properties of explosives, it is apparent the simple lab tests like lead block expansion, sand crush, etc. are quite crude (but far
from useless) at characterizing explosive performance.
But the total energy in the explosion is absolutely linear in the amount of explosive employed.
[Edited on 30-12-2015 by careysub]
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nitro-genes
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Plate dent, leadblock expansion/compression and sand crush test are somewhat crude tests indeed, all measuring different aspects of "explosive power".
Lead block expansion is probably the best in estimating total energy output, but likely least effective in predicting shaped charge performance. Plate
acceleration in an infinitely large absolute vacuum would come close I think, but if the plate thickness and weight would approach zero, you would
probably only find the VoD. 
[Edited on 30-12-2015 by nitro-genes]
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PHILOU Zrealone
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| Quote: Originally posted by careysub | | Quote: Originally posted by PHILOU Zrealone |
For a given explosive, the increase of explosion power is quadratic as a function of weight, not linear!
EP = A*(weight)²
A being a constant dependant of the geometry of the explosive charge, density of it and of the explosive itself...
This effect is obvious when plotting lead block test expansion as a function of weight of explosive for various explosives... |
Assuming the stated lead block test results are as you say (I have not tried to check - I would appreciate a link if you have one), then this is true
only if "explosion power" is a term defined by the lead block test results, which out of necessity only deals with small amounts of
explosives.
Under such conditions non-linear effects with energy dissipation mechanisms, edge effects, detonation build-up, material yield properties, etc. are
quite plausible.
With the advent of sophisticated numerical modeling techniques for explosives, and much more detailed understanding of the fundamental thermodynamic
and other physical properties of explosives, it is apparent the simple lab tests like lead block expansion, sand crush, etc. are quite crude (but far
from useless) at characterizing explosive performance.
But the total energy in the explosion is absolutely linear in the amount of explosive employed.
[Edited on 30-12-2015 by careysub] |
There is a graph somewhere (I can't get my hand on it) that displays the explosive power of Triazido-trinitrobenzene vs other primaries as a function
of weight and resulting sand crushed...
There you see it is quadratic.
There is also that very interesting document I requested in document request and translations (9) the document was provided by Boffis and by Solo a little later.
If you plot those datas Inside excel and that you do a little maths you get this: I'm stil working on those fabulous datas!
This is fabulous because:
1°)if you know this, you will be able to compare all explosives vs each other by weight but also by volume simply by knowing their parameters A and
B:
LBT= A*x² + B
A is dependant of the geometry of the Lead Block Test, B is dependant of the detonator power and of sensitivity of the explosive material to
initiation.
The volumic power is something that link many explosives under general rules...at first I have made assumptions by simple linear extrapolations...but
this precise quadratic dependance is very interesting to get precise predictive datas.
2°)Considering the usual cylindrical Lead Block Test single point with help of those spherical LBT datas, one can convert the single point info into
a precise extrapolated curve. Indeed one will easily find back A and B for the conventional cyclindrical LBT for all given explosive (Medina; TNT;
RDX; Tetryl; HMX) and then for all explosives tested by the single point cylindrical LBT.
3°)The Lead block Test is biased by the use of a detonator...if the Lead Block Test was made with pure explosive D2D then the very important point 0
cm³ for 0 gr explosive(common for all explosives could be used)!
Of course the use of primaries as initial study case will be very important because they detonate from flame in minute amounts and they will give the
idea on how explosive behave in large amount under self propagating detonation. Below a certain weight no detonation is observed and the quadratic
dependance is not observed but at a certain weight its expansion will be exponential until it reaches the quadratic curve.
4°)I have a lot of lead at home, the spherical design allows one to use much less lead than for a cylinder...also knowing that you can play with
mini-sphere is very interesting for amateur experimentalists like us...we could then provide interesting LBT datas with less lead and less
explosive...
This is of course also of interest to scientist who have little explosive material under hand to test or who don't have the possibility to cast and
manipulate large LBT (can be very heavy and energy consuming)!
[Edited on 1-1-2016 by PHILOU Zrealone]
Here is also a proof about the effect of the detonator...sadly I don't have its origin because it is saved image from a post of another user...
[Edited on 1-1-2016 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
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ecos
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@PHILOU Zrealone,
Let me help you , the last image in your post is from : Nitroglycerine and Nitroglycerine Explosives by Phokion Naoum
You can avoid the effect of detonator by adding metal oxide powder. this will avoid the low velocity detonation by increasing the speed of detonation
wave inside the EM
The attached patent deal with the probs but the sensitivity will be increased for the Gelatine
Attachment: US2362617.pdf (281kB)
This file has been downloaded 568 times
Note: the link in your post is not working !
[Edited on 2-1-2016 by ecos]
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nitro-genes
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Did they correct for the amount of volume in the sphere? If the wallthickness of the sphere decreases due to a larger cavity with increasing explosive
amount, then the energy is of course increasingly more efficiently transferred to aid expansion.
There probably is a large database having all these test data for a large number of known explosives. Wondered if it would be interesting to put them
all in a statistical model and look at correlations and interactions between various physical properties. Most likely however, many of the test
results would show strong correlations with many factors but also interactions, which would limit it's use to make ab inito predictions, even more so
since the conditions of the test itself probably interact somewhat with the explosive used to determine the outcome. All explosive properties like
density, VoD, energy released, volume and nature of gasses produced, etc will interact not only with each other, but also with the test itself. Even
with a very large dataset and all tests performed under the most rigorously controlled conditions, there would be far to many factors to separate to
come to a robust predictive model IMO.
Although not directly related to your post, similar things might happen when comparing primaries using LBT, a big confounder here would be the
acceleration of the detonation wave, which is much faster for azides for example then for DDNP. It would be interesting to see whether small scale LBT
for primaries like you desribe indeed would be a good predictor of "initiation potential".
[Edited on 2-1-2016 by nitro-genes]
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PHILOU Zrealone
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| Quote: Originally posted by ecos | @PHILOU Zrealone,
Let me help you , the last image in your post is from : Nitroglycerine and Nitroglycerine Explosives by Phokion Naoum
You can avoid the effect of detonator by adding metal oxide powder. this will avoid the low velocity detonation by increasing the speed of detonation
wave inside the EM
The attached patent deal with the probs but the sensitivity will be increased for the Gelatine
Note: the link in your post is not working !
|
Thank you for the picture lost reference.
Interesting effect of Metal oxydes and Metals indeed!
This effect, if real, should be visible with the Lead block test...since a higher VOD will display more deformation energy.
My link does works for me with "Internet Explorer" and with "Google Chrome" navigators...
Anyway, you could do a fast search with the search tool of the forum into the reference folder 9 under poster PHILOU Zrealone with key word Lead Block
Test 
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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PHILOU Zrealone
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| Quote: Originally posted by nitro-genes | Did they correct for the amount of volume in the sphere? If the wallthickness of the sphere decreases due to a larger cavity with increasing explosive
amount, then the energy is of course increasingly more efficiently transferred to aid expansion.
There probably is a large database having all these test data for a large number of known explosives. Wondered if it would be interesting to put them
all in a statistical model and look at correlations and interactions between various physical properties. Most likely however, many of the test
results would show strong correlations with many factors but also interactions, which would limit it's use to make ab inito predictions, even more so
since the conditions of the test itself probably interact somewhat with the explosive used to determine the outcome. All explosive properties like
density, VoD, energy released, volume and nature of gasses produced, etc will interact not only with each other, but also with the test itself. Even
with a very large dataset and all tests performed under the most rigorously controlled conditions, there would be far to many factors to separate to
come to a robust predictive model IMO.
Although not directly related to your post, similar things might happen when comparing primaries using LBT, a big confounder here would be the
acceleration of the detonation wave, which is much faster for azides for example then for DDNP. It would be interesting to see whether small scale LBT
for primaries like you desribe indeed would be a good predictor of "initiation potential".
[Edited on 2-1-2016 by nitro-genes] |
Very interesting point of view and debate
Have you downloaded the document from my link?
It is wel expressed...the dimensions of the sphrere LBT are identical to classical cylindrical LBT, except it is spherical...so the inner cylinder to
place the charge is 100% identical.
The sphere is inscriptible inside the cylinder...so both display the same diameter.
From what I have seen the difference in LBT expansion is almost the same.
[Edited on 2-1-2016 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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ecos
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| Quote: Originally posted by PHILOU Zrealone |
Interesting effect of Metal oxydes and Metals indeed!
This effect, if real, should be visible with the Lead block test...since a higher VOD will display more deformation energy. |
as i understand, the LBT doesn't take into consideration the effect of the detonator. With different cap number we should have different Trauzl
number. I think this effect is for nitric esters only.
From Wiki , NG has higher Trauzl number than HMX, while HMX has higher VoD than NG !however the most important thing in SC is the VoD. The higher is
the better.
I didn't get your point of mentioning the LBT in this thread. I am really sorry if i got lost.
I am also interested about this effect of adding metal oxides to accelerate the detonation wave inside EM. do you know any analytical way to calculate
it ? I don't think the patent is mistaken .
[Edited on 3-1-2016 by ecos]
[Edited on 3-1-2016 by ecos]
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nitro-genes
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Hi Philou,
The link didn't seem to work here too, found It by using the search engine like you suggested. I was merely guessing about the cause of the observed
non-linearity in the graph you posted. Pretty clever using a spherical block to prevent cracking.
[Edited on 5-1-2016 by nitro-genes]
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PHILOU Zrealone
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| Quote: Originally posted by nitro-genes | Hi Philou,
The link didn't seem to work here too, found It by using the search engine like you suggested. I was merely guessing about the cause of the observed
non-linearity in the graph you posted. Pretty clever using a spherical block to prevent cracking.
[Edited on 5-1-2016 by nitro-genes] |
Because there seems to be troubles...here is the direct download link fully written http://www.sciencemadness.org/talk/files.php?pid=401766&aid=39137
[Edited on 5-1-2016 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
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PHILOU Zrealone
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| Quote: Originally posted by ecos | | Quote: Originally posted by PHILOU Zrealone |
Interesting effect of Metal oxydes and Metals indeed!
This effect, if real, should be visible with the Lead block test...since a higher VOD will display more deformation energy. |
as i understand, the LBT doesn't take into consideration the effect of the detonator. With different cap number we should have different Trauzl
number. I think this effect is for nitric esters only.
From Wiki , NG has higher Trauzl number than HMX, while HMX has higher VoD than NG !however the most important thing in SC is the VoD. The higher is
the better.
I didn't get your point of mentioning the LBT in this thread. I am really sorry if i got lost.
I am also interested about this effect of adding metal oxides to accelerate the detonation wave inside EM. do you know any analytical way to calculate
it ? I don't think the patent is mistaken .
|
You wrote:
"If we assume linear equation this means the SC of Kornet should be 5.7 times the size/weight of Panzerschreck = 5.7 * 700g = 4 Kg of EM"
I expressed that the dependance is not linear but quadratic...and that's why I went to LBT...
LBT is a mix of many parameters, heat of explosion, volume of gases, VOD, pressure...it is correlated to p*V=n*R*T equation and reflects thus the
total work p*V (energy output).
I'll open a specific tread about LBT
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Fulmen
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And you'd be wrong. It's closer to an exponential curve, above a certain value you gain nothing from increasing the charge.
We're not banging rocks together here. We know how to put a man back together.
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