need suggestion for simulation !!!!!!! URGENT!!!!

Arthur Gamara

i have already made simulation for flow around bullet. i made 3 conditions: 1. just before bullet pass end of barrel (bullet-end of barrel-environment) 2. half body in barrel, another out of barrel 3. just bullet completely out from barrel

make asumption there is no distance between bullet, barrel and envy. i added pressure behind the bullet because the effect of blast, am i right??? also i didn't set the bullet to rotate, coz the rotation of the bullet is caused by it's geometry and movement,and it starts rotate after few moment it's leave the barrel outlet.

for meshing, there is no problem, but in fluent i'm very confused to make define this simulation. what's the best condition to make this simulation valid???

Can anyone help me??? Thanks very much for your suggestions ..!!!