[cheehau]

Hi everyone,

I am a super newbie in CFD and recently have been trying to model a multi-channel flow domain using ANSYS Fluent. My current result shows a somewhat sensible flow pattern but its velocity profile doesn't make any sense. I created streamlines from the inlets in the fluid body and they showed a sharp decrease in the velocity as shown in "CFD.png" photo. As you can see the flow velocity quickly decreased to 0 m/s.

The channels of the flow domain consist of exhaust and gas inlets. There are 11 channels with a sequence of exhaust and gas inlets alternating between. The CAD model was created using SolidWorks and it is a unibody which the flow domains of the 11 channels are part of the free flow domain that I created as shown in the attached geometry picture.

The boundary conditions that I set for my case are shown in the attached "meshing.png" and "setup.png" photos. I managed to set the gas inlets (including nitrogen_inlets, precursor_1_inlet, precursor_2_inlet) as velocity inlets. I also set the "exhaust_inlets" as a velocity-inlet with a negative velocity for suction. For the two surfaces where all the channels connect and the bottom surface, I set them as wall. I also set the surfaces of the channel, except the inlets as wall too. As shown in the "meshing.png", the red region is the freeflow region which I set them as pressure outlet (I also tried setting them as outflow which gave similar results).

As I mentioned at the beginning, the velocity profile showed a sharp decrease and quickly became 0. I am wondering if it is a convergence issue. The continuity I got when I run the model is around 0.2. I couldn't specify the outlet of each channel too because they are a unibody. Should I create another model with separate bodies (individual channels and the flow domain)?

The goal is to examine the interaction between the flows coming out from the channels and going into the exhaust.

Any feedback/comment/suggestion is much appreciated! I apologize for the long post. Please just let me know if you are confused with the setup. Thank you very much!


Best,
Chee

[cheehau]

Anyone please?