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won0726 November 24, 2020 09:38

rotating fan
 
Hi, I am a total beginner of using star ccm+ and I would like to get some help.
I followed the tutorial that is posted online/youtube that shows how to run the simulation, and I want to know the pressure difference between the inlet and outlet. So far, I got the area averaged inlet pressure, but my area averaged outlet pressure is constant 0. Thanks in advance.
Attaching the youtube site for reference.

https://www.youtube.com/watch?v=KvQc..._channel=Howto

fluid23 November 24, 2020 11:38

First of all, I don't think that tutorial has a report for average outlet pressure. However, it makes sense for a report placed on a boundary condition to return the target value/setting.

The outlet is a pressure outlet, with 0 gauge pressure (unless you changed it). You are telling the solver that the pressure at this plane is always 0 so that it can bound the problem and find a solution.

At the velocity inlet, you are specifying velocity rather than pressure and would get a similar result for area averaged inlet velocity.

cwl November 24, 2020 12:23

Reports -> Pressure Drop.

won0726 November 26, 2020 07:20

Quote:

Originally Posted by fluid23 (Post 788716)
First of all, I don't think that tutorial has a report for average outlet pressure. However, it makes sense for a report placed on a boundary condition to return the target value/setting.

The outlet is a pressure outlet, with 0 gauge pressure (unless you changed it). You are telling the solver that the pressure at this plane is always 0 so that it can bound the problem and find a solution.

At the velocity inlet, you are specifying velocity rather than pressure and would get a similar result for area averaged inlet velocity.

Thanks for the reply. So in order to find the outlet pressure, do i have to change the gauge pressure which is 0? From the region - fluid-boundaries-pressure-physical values-pressure is at a constant 0 Pa, do i have to change the physics condition?

cwl November 26, 2020 07:22

Quote:

Originally Posted by won0726 (Post 788943)
So in order to find the outlet pressure, do i have to change the gauge pressure which is 0? From the region - fluid-boundaries-pressure-physical values-pressure is at a constant 0 Pa, do i have to change the physics condition?

I'm afraid - you have to read a bit about what pressure first.

won0726 November 26, 2020 07:24

Quote:

Originally Posted by cwl (Post 788720)
Reports -> Pressure Drop.

Thanks for the reply. I tried using the pressure drop. So the high pressure would the 2 interfaces from the fluid:inlet and the low pressure would the fluid:pressure which is the boundary?

won0726 November 26, 2020 07:29

Sorry but can you be a bit more specific?


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