[Nrafagnim]

Dear all,

I'm simulating the oxygen flow from a nozzle to an open reactor filled with air (23% oxygen and 77% nitrogen). All fluids temperature are 300K, the outlet pressure is 101325 Pa and the velocity reaches about 300 m/s. I'm using simpleSprayFoam with k-omega SST turbulence model and I'm getting a very strange backflow behaviour. We expected that the air would flow towards the central region of the reactor, but it is flowing downwards.

What am I doing wrong? Or is my understanding about the flowfield wrong?

I'm attaching some images from the OpenFOAM simulation (velocity field with velocity vectors and temperature fields) and one from the same simulation using Fluent. My 0 folder is also attached. The simulation ran for 800 iterations and the flow is not significantly changing anymore.
We aim to study the combustion of an ethanol spray, that's why we are using simpleSprayFoam.

Thank you very much!