Surferus
July 18th, 2006, 09:18 PM
Dear gentlemen,
There was a long time I've been trying to find the best way to detonate the mix of granulated AN with 4-5% of diesel fuel added.
I started my research in the area of this explosive because it is cheap and easy to prepare.
The detonation wave is formed by the local increases of the density of substance. Of course as many of us know from school, the speed of the wave depends on two things: density of the substance and the Jung module of the given substance (often refered to as E). After writing some quite easy formulas, one can conclude that V ~ sqrt(E/d), where d is density, V is the speed of detonation wave.
Again, the equation above gives us a simple understanding of why, for example, the speed of detonation for granulated explosives is lower than that for ground explosives, like ammonal or ground and pressed TNT.
The main reason is that E module for granulated explosives is lower. When a pressure is applied to granulated material, granulas change their shape and become ellipsoids with considerable eccentricity rather than spheres. When the size of granulas is big, this leads to sharp decrease of volume and the smaller the granulas are, the less considerable this decrease is.
Even when the container with explosive is weak (plastic or paper), detonation wave reflects on it (or even on the surface of the charge), and thus our main goal is (roughly speaking) to make the wave maximums of reflected wave to be just in the places where maximums of the original wave were. Thus even if our ANFO charge doesn't detonate completely from the original detonation wave, refelected wave accomplishes the business.
Yes, matching the needed maximums at least requires us to know the exact speed of detonation wave in the substance. But look at the first two paragraphs of my post. The speed can be deducted from measuring the size of granulas, because, to our happiness, manufactures make AN granulas shape very close to spherical. I tried to write a numerical simulation progam that would calculate the approximate detonation speed for material which consists of spherical particles of given E, but I am only partly sucessfull so far.
I am now going to conduct at least 4 tests to check if my theory works.
I guess there is a place where many professionals gather to share the knowledge, thus I would be very glad if someone of them told me if simular works have ever been performed and what the results were.
There was a long time I've been trying to find the best way to detonate the mix of granulated AN with 4-5% of diesel fuel added.
I started my research in the area of this explosive because it is cheap and easy to prepare.
The detonation wave is formed by the local increases of the density of substance. Of course as many of us know from school, the speed of the wave depends on two things: density of the substance and the Jung module of the given substance (often refered to as E). After writing some quite easy formulas, one can conclude that V ~ sqrt(E/d), where d is density, V is the speed of detonation wave.
Again, the equation above gives us a simple understanding of why, for example, the speed of detonation for granulated explosives is lower than that for ground explosives, like ammonal or ground and pressed TNT.
The main reason is that E module for granulated explosives is lower. When a pressure is applied to granulated material, granulas change their shape and become ellipsoids with considerable eccentricity rather than spheres. When the size of granulas is big, this leads to sharp decrease of volume and the smaller the granulas are, the less considerable this decrease is.
Even when the container with explosive is weak (plastic or paper), detonation wave reflects on it (or even on the surface of the charge), and thus our main goal is (roughly speaking) to make the wave maximums of reflected wave to be just in the places where maximums of the original wave were. Thus even if our ANFO charge doesn't detonate completely from the original detonation wave, refelected wave accomplishes the business.
Yes, matching the needed maximums at least requires us to know the exact speed of detonation wave in the substance. But look at the first two paragraphs of my post. The speed can be deducted from measuring the size of granulas, because, to our happiness, manufactures make AN granulas shape very close to spherical. I tried to write a numerical simulation progam that would calculate the approximate detonation speed for material which consists of spherical particles of given E, but I am only partly sucessfull so far.
I am now going to conduct at least 4 tests to check if my theory works.
I guess there is a place where many professionals gather to share the knowledge, thus I would be very glad if someone of them told me if simular works have ever been performed and what the results were.