Boundary condition definition problem for detonation
 

Hello Users,

I am doing first steps with CFD and currently working on a project with my profesor regarding detonation in detonation pipe.

The problem looks as shown below. There is no inlet nor outlet and simulation is transient.
My question is how to define such initial conditions, that the first part of geometry has pressure of 8 bar and the remaining two parts have 1 bar and how to define that the whole boundary consist of stochiometric mixture of hydrogen and air.

Attachment 92459

The second question is how to import combustion mechanism for detonation of hydrogen-air mixture? My profesor told me to use this. Below only part of the mechanism is shown.

Attachment 92460
source: https://www.universityofgalway.ie/co...nismdownloads/
Hydrogen (2004)

Should I use only reaction mechanism or thermodynamics and transport too?