# Black powder detonation analysis in ANSYS

I have an Aluminium tube that I want to insert some black powder in it and explode. This will be used as a ejection system for a high altitude rocket. It will deploy two bodies or nose cone of the rocket.

How to make a detonation analysis with ANSYS? I have used TNT instead of black powder because ANSYS does not contain black powder material. I plan to use about 3.5 grams of black powder to ejection so I used the TNT equivalency of it to make analysis. But I cannot be sure about equivalency ratio. My research says the maximum TNT equivalency of black powder based on pressure is %24 as grams. 3,5 * 24/100 = 0,836 gram and density of TNT is d = 1,65 g/cm^3. Then I calculated the volume of TNT as 0,506 cm^3 by using m = d*V equation. I designed a rectangular prism and added it to my assembly. Then I made the detonation analysis but the results of it were unrealistic. I think problems about this analysis are:

1. The black powder will not take place in such a tight prism as I drew in analysis.
2. The maximum rate of 24% causes the result to stress values much more then normal.

What should I do to make an accurate analysis? What parameters should I focus on? How can I use the black powder as a material in a detonation analysis or how can I calculate realistic equivalency TNT and black powder?