Stratified environment
 

Hi CFX Users,

I am simulating a case into a small rectangular box(length=width=1m, height=0.3m) open top, wall non-slip rigid insulated and bottom also insulated except the small nozle(r=0.005m) for injecting single phase water jet flow inside it. Newtonian stratified single phase fluid is considered in this box. From calculation, I put water jet velocity0.0343m/s and its temperature 298.64K. As stratified fluid stay in the box so every meter of height of the box temperature will chage N=8.155 K/m so i write an expression To=302.44-N* Z coordinate, and initializes it . Choose bouyancy and its temperature 300K from setup as this is a negative bouyancy case.

mesh sizes 3mm, time step 0.087 with 1.8million of mesh, I run this simulation for 400sec.
Everything fine , simulation finished well but the problem is jet flow penetration height inside this box is not long enough what we expected from previous investigations done by another people in fluent.

I do not understand what is happening. I tried in different way but no solutions i get till now.

If anybody give me any suggestion it will be a great help for me.Because around me knowbody actually know CFX.

Regards

HMR

Can you confirm that your temperature function just defines the intial condition? Obvious from there the air establishes its own temperature field in the simulation.

Have a look at this FAQ: http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F

Hi Glenn,

Thanks for your reply. Yes I am trying to figure out the problem according to your advice.

Cheers

HMR

Attach some pictures of your results so ppl here can analyse.