# Model and Boundary Conditions for Flow around a Bullet in Ansys Fluent

 Register Blogs Members List Search Today's Posts Mark Forums Read

 March 3, 2017, 17:33 Model and Boundary Conditions for Flow around a Bullet in Ansys Fluent #1 New Member   Chaithanya Adapa Join Date: Mar 2017 Posts: 2 Rep Power: 0 Hello Everyone I am working on a project to study the Flow around Long Range Bullets particularly Remington Fireball. I thought of simulating the flow in Ansys Fluent but I have no idea which boundary conditions and which model will give a realistic estimate of Drag on the bullet in such supersonic conditions Any ideas and References would be Deeply appreciated Thank you

 March 3, 2017, 17:48 #2 New Member   Justin B. Join Date: Mar 2017 Posts: 7 Rep Power: 8 Perhaps this may give you a good starting point: https://confluence.cornell.edu/displ...+Specification I imagine your problem will be a somewhat similar setup.

March 3, 2017, 17:59
#3
New Member

Join Date: Mar 2017
Posts: 2
Rep Power: 0
Quote:
 Originally Posted by jabier14 Perhaps this may give you a good starting point: https://confluence.cornell.edu/displ...+Specification I imagine your problem will be a somewhat similar setup.
Thanks for the reply Here we are talking about the mach regimes oh 3-3.5 as the the velocity of remmington fireball bullet will be at speeds of 1200m/s and that seems to result in bubble shock waves as like below

so the above analysis comes short i guess

March 5, 2017, 21:45
#4
Senior Member

Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,146
Rep Power: 61
Quote:
 Originally Posted by chaithanya1996 Thanks for the reply Here we are talking about the mach regimes oh 3-3.5 as the the velocity of remmington fireball bullet will be at speeds of 1200m/s and that seems to result in bubble shock waves as like below https://www.youtube.com/watch?v=gnhbhpwTx1c so the above analysis comes short i guess
Replace the wedge with your bullet. Change the inlet properties to achieve your desired wind speed. It is straightforward. How does it come short of your expectations? What exactly do you want to do that is not answered?

The skin friction does not contribute much to the drag compared to across the shockwaves, so it really doesn't matter if you use a turbulence model.

There's two ways you can setup the problem. With the bullet stationary and some sort of supersonic inlet, or you can explicitly specify a velocity for the bullet and use a simple pressure inlet (with pressure equal to atmospheric pressure). I recommend the later.

 Tags ansys, bullet, cfd, fluent, supersonic