Fluid flow fluent

ali.soufan · October 7, 2015, 11:26

Hello everyone,
I am working on my senior project which is car park i need to get the result of velocity distribution in the car park to identify the
Lowest velocity area in the carpark.
I finish the geometry part and mesh part.
I need some help in setup part which equations should i generate in models ?
In the carpark there is 1 axial exhaust fan 4000 cfm and 2 fresh air louver each 1300 cfm which boundary condition should i choose for them?

Thank you

Jeeloong · October 7, 2015, 11:48

Quote:

Originally Posted by ali.soufan

Hello everyone,
I am working on my senior project which is car park i need to get the result of velocity distribution in the car park to identify the
Lowest velocity area in the carpark.
I finish the geometry part and mesh part.
I need some help in setup part which equations should i generate in models ?
In the carpark there is 1 axial exhaust fan 4000 cfm and 2 fresh air louver each 1300 cfm which boundary condition should i choose for them?

Thank you

I think you can have mass-flow inlet. The best is to work you your area and how much flow you want it to be.

I don't quite get what you meant by equations**

ali.soufan · October 7, 2015, 13:03

I explain it wrong my question was what should i generate in the models like i generate energy equation what else?
Did you get what i mean
Thank you

fresty · October 12, 2015, 10:34

You would not need energy equations if it's only the velocity distribution of air (momentum equation) that you're looking for.

Jeeloong · October 31, 2015, 17:48

Hi Ali,

from the above description I think you only need to use Turbulence Model. I would imagine the fan that draw air into the carpark will cause Turbulence. And hence you will see the effect by Vector plot or Contour velocity plot.

First you need to define what velocity is realistic which is the rotating speed of fan in the carpark. I not sure whether is constant velocity or constant mass flow rate. Then you must also define the outlet. which u can say 0 pressure outlet which is release to atmosphere.

You can try with different Turbulence Model to see the results. Do you have any experimental data to compare with?

Thanks

Kind Regards,
Jee Loong

Jeeloong · October 31, 2015, 17:50

Check the Reynolds number,

Whether is laminar or Turbulence. Most engineering case is Turbulence.

So you mostly need K-e/K-w or RSM model.

Read the theory guide and decide which one justify your performance and cost.

How fast you need the data. Is it within 1 month? How big is your mesh.

Go with basic K-e Turbulence Model

Do you need enhanced wall function (wall treatment)? (depends on your y+)

ali.soufan · October 31, 2015, 17:58

Hi jee first thank you alot for your replying, i have a small dv room i am trying to done the jet fan on it and after i will put it in my carpark project when it works. So i can show you experimentally project on dropbox i can send you the link what do you think can you help me ?

ali.soufan · October 31, 2015, 18:05

i draw cylinder which is the jetfan but theirs is a problem this cylinder doesn't change the flow inside the room the flow flows inside the cylinder and doesn't effect the interior of the room.

Jeeloong · October 31, 2015, 18:14

Hi Ali Soufan,

Sorry the CFD Online prohibits users from discussion in private to be honest.

I suggest you take a screen shot of your domain (If not confidental such as company work) and open a new thread for discussion. I can have a look there.

Ok if your distance of ur fan is far away from the car. I will say the velocity distribution will not be affected much if it is far away. If it is too close u might expect transient behaviour. Also depends heavily on your geometry. If ur fan is symmetry then u can model symmetry to save timing solving NS equations (RANS).

Thanks.

Post it in a new thread.

October 7, 2015, 11:26	Fluid flow fluent	#1
ali.soufan New Member Join Date: Mar 2015 Posts: 22 Rep Power: 11	Hello everyone, I am working on my senior project which is car park i need to get the result of velocity distribution in the car park to identify the Lowest velocity area in the carpark. I finish the geometry part and mesh part. I need some help in setup part which equations should i generate in models ? In the carpark there is 1 axial exhaust fan 4000 cfm and 2 fresh air louver each 1300 cfm which boundary condition should i choose for them? Thank you

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October 7, 2015, 13:03		#3
ali.soufan New Member Join Date: Mar 2015 Posts: 22 Rep Power: 11	I explain it wrong my question was what should i generate in the models like i generate energy equation what else? Did you get what i mean Thank you

October 12, 2015, 10:34		#4
fresty Senior Member Join Date: Aug 2014 Location: UK Posts: 213 Rep Power: 12	You would not need energy equations if it's only the velocity distribution of air (momentum equation) that you're looking for.

October 31, 2015, 17:48		#5
Jeeloong Member Join Date: Jan 2015 Location: United Kingdom Posts: 53 Rep Power: 11	Hi Ali, from the above description I think you only need to use Turbulence Model. I would imagine the fan that draw air into the carpark will cause Turbulence. And hence you will see the effect by Vector plot or Contour velocity plot. First you need to define what velocity is realistic which is the rotating speed of fan in the carpark. I not sure whether is constant velocity or constant mass flow rate. Then you must also define the outlet. which u can say 0 pressure outlet which is release to atmosphere. You can try with different Turbulence Model to see the results. Do you have any experimental data to compare with? Thanks Kind Regards, Jee Loong

October 31, 2015, 17:50		#6
Jeeloong Member Join Date: Jan 2015 Location: United Kingdom Posts: 53 Rep Power: 11	Check the Reynolds number, Whether is laminar or Turbulence. Most engineering case is Turbulence. So you mostly need K-e/K-w or RSM model. Read the theory guide and decide which one justify your performance and cost. How fast you need the data. Is it within 1 month? How big is your mesh. Go with basic K-e Turbulence Model Do you need enhanced wall function (wall treatment)? (depends on your y+)

October 31, 2015, 17:58		#7
ali.soufan New Member Join Date: Mar 2015 Posts: 22 Rep Power: 11	Hi jee first thank you alot for your replying, i have a small dv room i am trying to done the jet fan on it and after i will put it in my carpark project when it works. So i can show you experimentally project on dropbox i can send you the link what do you think can you help me ?

October 31, 2015, 18:05		#8
ali.soufan New Member Join Date: Mar 2015 Posts: 22 Rep Power: 11	i draw cylinder which is the jetfan but theirs is a problem this cylinder doesn't change the flow inside the room the flow flows inside the cylinder and doesn't effect the interior of the room.

October 31, 2015, 18:14		#9
Jeeloong Member Join Date: Jan 2015 Location: United Kingdom Posts: 53 Rep Power: 11	Hi Ali Soufan, Sorry the CFD Online prohibits users from discussion in private to be honest. I suggest you take a screen shot of your domain (If not confidental such as company work) and open a new thread for discussion. I can have a look there. Ok if your distance of ur fan is far away from the car. I will say the velocity distribution will not be affected much if it is far away. If it is too close u might expect transient behaviour. Also depends heavily on your geometry. If ur fan is symmetry then u can model symmetry to save timing solving NS equations (RANS). Thanks. Post it in a new thread.