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-   -   Simulation in a laboratory. (difficulty in deciding location of inlet) (https://www.cfd-online.com/Forums/phoenics/127001-simulation-laboratory-difficulty-deciding-location-inlet.html)

otc0101 December 1, 2013 09:21

Simulation in a laboratory. (difficulty in deciding location of inlet)
 
Hi, I'm a student from Universiti Putra Malaysia. I'm a newbie in Phoenics and CFD however I was given assignment to do a simulation on laboratory air ventilation. Here i give a brief description of the lab:
A tall building, with 2 doors on ground (always open), 1 door facing empty space while the other door is facing passage between other labs.
there are few windows at top of the left and right walls of lab.

a) I'm having confusion which door/window should i set as inlet/outlet. From my point of view, I would say the door facing empty space is inlet while the other door and windows on top are outlet. Anyone mind to clarify me for this?

b) In PHOENICS, if i wish to simulate a fan, do i have to use FLAIR in PHOENICS or just CORE, then there will be an option in Object as fan?

c)any rule of thumb to determine inlet and outlet velocity? i will assume outside temperature (weather) as inlet temperature, but i had no clue on inlet velocity, outlet temperature and velocity

Thank you for time in advance for reading and answering.

Wikie December 9, 2013 04:04

Hi,

lets see if we can get some light into the darkness :-)

a) It's up to you which window/ door you define as inlet resp. outlet. In this case it's also possible to define all windows / doors as outlets. If so, you have to define the external pressure at each outlet. The volume flow will be a result of the pressure difference between the outlets.

b) You can also use Core, it also includes fan objects. In general I would prefer Flair to do indoor simulations - if it's available for you.

c) If you're using outlets for all windows /doors you don't have to define the inlet velocity, it will be a result of the pressure difference.

cheers
wikie

otc0101 December 9, 2013 05:09

Thank you for the reply, Wikie. Too bad, I have no idea how to define pressure in the lab and pressure outside the lab. Mind to give any guide? If in the end I couldn't get any information, my last resort will be using inlet with velocity based on wind speed

Wikie December 9, 2013 07:59

Hi,

you don't have to define the pressure inside the lab, it's relative to the outside pressure.
If you're going to use the wind velecity as inlet velocity you should place your inlets at that building side which is facing towards the wind direction and your outlets at the leward side of your building.

cheers
wikie

otc0101 December 9, 2013 08:16

Once again, thank you. I will try to figure out the way to create pressure difference.


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