Solution Problems-output velocity looks like input

[mmcginnis_bmcd]

I am working on a project. The overall project that has 3 outlets, shown in the first attachment. But when I look at the solution it looks like one of the outlets is actually an inlet of water, this can be seen in the second attachment. The arrows can be seen in RED showing high velocity, but they are going in the wrong direction. The third attachment shows more of what I was expecting.

Can anyone explain why its happening with this outlet?

[Royce_adsk]

Are you able to attach the support file or provide a link through DropBox or A360?

Thanks,

[mmcginnis_bmcd]

I have attached my solution from Simulation CFD.

The problem is that they only have boundary conditions that have output velocities.

[Royce_adsk]

Hi!

Reference this post on how to send use models: http://forums.autodesk.com/t5/Simulation-CFD/Need-to-send-us-your-simulation-model-to-review/td-p/47...

Thanks,

[mmcginnis_bmcd]

The cfz file was too large, so I loaded it onto Autodesk 360 and made it public.

http://a360.co/1ix5cFF

Here are also a few more static images that I took from my solution model. These are z-sections and shaded x-sections of my problem area.

[Royce_adsk · Accepted solution]

Hello:

Your model has 3 outlets with 0 inlets.  To conserv mass you need to have fluid coming in through an inlet unless you are tyring to model a free surface/height of fluid type of simulation.

What are your goals here, should water be coming in from the top?

Cheers,

[mmcginnis_bmcd]

I guess that makes sense.

The Situation is that water flows from a cooling tower into the opening in the top that is actually covered by a grate. (This grate was not modeled in CFD because it was over complicating the model and causing it to crash) The water is just free falling from above and filling the space. I did not use a free surface because that requires a transient solution and I am wanting to show the water height of 6 ft. because if the water level gets too low the outlets start mixing water and air which causes Simulation CFD to crash. Unforlunately thi sis what is actually happening in the real work, but I have to work within the limitations on the program.

I have attached a basic PDF showing what is happening and a few pictures from the site (the first is of the drain grating from above and the second is a photo of the inside of what I am actually modeling).

If anyone has any suggestions on how to model the water being drained into the system that would be very helpful.

[mmcginnis_bmcd]

I understand that I have to respect the conservation of mass, but I don't want to limit the model. It was suggested that I assign a P=0 for the top inlet. Any ideas if that would be helpful rather than adding a velocity that equals the outlet of water?