MineMan
International Hazard
Posts: 1012
Registered: 29-3-2015
Member Is Offline
Mood: No Mood
|
|
Detonation Modeling
I would like to model detonations and gurney velocities with different percentage and size Metal powders...
Does anyone know of any open source code...?? I am guessing it would be thermochemistry similar to JAGUAR and CHEETAH
https://apps.dtic.mil/dtic/tr/fulltext/u2/a528198.pdf
Here’s how they do it in the military, but I don’t have CHEETAH. Any help would be fantastic, I am willing to work with an university.
Are thier platforms built for this... for example for shape charges you can enter equations and use Autodyn... I think
Thank you all.
|
|
|
Dornier 335A
Hazard to Others
Posts: 231
Registered: 10-5-2013
Location: Northern Europe
Member Is Offline
Mood: No Mood
|
|
Calculating detonation velocity of explosive mixtures with aluminium is not too difficult. Assuming inert aluminium powder gives good agreement with
experimental results.
This might not work if the particle size is small enough to react before the CJ point though...
Predicting gurney velocities is on another level since the metal will have time to react, but you need to know when it reacts during the
expansion. Drawing a straight line from the unreactive
CJ-state to the reactive isentrope seems to work fairly well according to "Eigenvalue Detonation of Combined Effects Aluminized Explosives".
|
|
|
MineMan
International Hazard
Posts: 1012
Registered: 29-3-2015
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Dornier 335A  | Calculating detonation velocity of explosive mixtures with aluminium is not too difficult. Assuming inert aluminium powder gives good agreement with
experimental results.
This might not work if the particle size is small enough to react before the CJ point though...
Predicting gurney velocities is on another level since the metal will have time to react, but you need to know when it reacts during the
expansion. Drawing a straight line from the unreactive
CJ-state to the reactive isentrope seems to work fairly well according to "Eigenvalue Detonation of Combined Effects Aluminized Explosives".
|
Dornier. Thank you for the reply, always look forward to your answers!
I should have been more specific. I am not interested in modeling VOD, rather how long it takes for different metal powders to combust at different
sizes. For example, they found that 15micron aluminum reacts by 7 volume expansions in a 1” cylinder with RDX and a binder.
I want to do the same but for larger diameters under more confinement (Mining). For example how many milliseconds and volume expansions before the
aluminum combust 90 percent in a 100mm dia hole, 200mm dia hole and etc. this becomes trickery because aluminum’s melting tempature changes with
pressure. And we know with a explosive dia of 200mm the aluminum will be under that pressure longer then the 25mm cylinder.
How would I go about this? The next step would be for me to model different particle sizes with different explosive diameters.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
