Human factor in fluent

dinodefender · February 15, 2019, 16:09

Hi everyone,
I am trying to include human volume to my current project. Consider that I have a room and it takes around 40 people in it and I am simulating the air flow in it with people inside and without inside of it, so how can I count the human volume in it? Thank you for your help

Simbelmynë · February 16, 2019, 15:36

The average density of a human is about the same as water or slightly larger. Total mass of 40 people varies a lot depending on country.

Average weight of a man in japan is about 67 kg and average weight of a man in the US is about 89 kg.

With this known it is just a matter of how coarse your approximation of the human body will be. A cuboid shape might be sufficient.

dinodefender · February 16, 2019, 17:57

After obtaining the average human physical parameters should I create a new solid with a volume of [volume of the room - volume of the humans] or is there a technique to mark where they will stand in room with a certain volume and then fluent will simulate the flow considering these parameters? I am very confused about it

Simbelmynë · February 17, 2019, 05:12

Just change the geometry and create a new mesh with the "humans". How you place the humans in the room depends on what type of room it is.

Also, if you are modelling weak ventilation then remember that natural convection from the humans (that generate about 100 W each) can be a factor.

dinodefender · February 17, 2019, 06:54

Well I considered them as seated and placed cubes on their place. I have created 2 geometries, in the first one I literally sculpted cubes to my solid room

(I still have doubts about it tho) but in the second one I created the same room geometry as an empty box and placed cubes inside of it. Are these suitable approach?

Simbelmynë · February 17, 2019, 09:43

Not sure what you mean. It depends on the type of solver you are using for the CFD. If you use an unstructured solver (e.g. Fluent) then you only create geometry for the fluid, so then the humans would be removed from the box, creating "holes" in the box of fluid that you are modeling. If you are using a cut-cell type of solver (e.g. Flow-3d or Phoenics) then you would designate the humans as blocked regions, but the base mesh would remain.

February 15, 2019, 16:09	Human factor in fluent	#1
dinodefender New Member Doğaç Zaman Join Date: Feb 2019 Posts: 10 Rep Power: 7	Hi everyone, I am trying to include human volume to my current project. Consider that I have a room and it takes around 40 people in it and I am simulating the air flow in it with people inside and without inside of it, so how can I count the human volume in it? Thank you for your help

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February 16, 2019, 17:57		#3
dinodefender New Member Doğaç Zaman Join Date: Feb 2019 Posts: 10 Rep Power: 7	After obtaining the average human physical parameters should I create a new solid with a volume of [volume of the room - volume of the humans] or is there a technique to mark where they will stand in room with a certain volume and then fluent will simulate the flow considering these parameters? I am very confused about it

February 17, 2019, 05:12		#4
Simbelmynë Senior Member Join Date: May 2012 Posts: 551 Rep Power: 16	Just change the geometry and create a new mesh with the "humans". How you place the humans in the room depends on what type of room it is. Also, if you are modelling weak ventilation then remember that natural convection from the humans (that generate about 100 W each) can be a factor.

February 17, 2019, 06:54		#5
dinodefender New Member Doğaç Zaman Join Date: Feb 2019 Posts: 10 Rep Power: 7	Well I considered them as seated and placed cubes on their place. I have created 2 geometries, in the first one I literally sculpted cubes to my solid room (I still have doubts about it tho) but in the second one I created the same room geometry as an empty box and placed cubes inside of it. Are these suitable approach?

February 17, 2019, 09:43		#6
Simbelmynë Senior Member Join Date: May 2012 Posts: 551 Rep Power: 16	Not sure what you mean. It depends on the type of solver you are using for the CFD. If you use an unstructured solver (e.g. Fluent) then you only create geometry for the fluid, so then the humans would be removed from the box, creating "holes" in the box of fluid that you are modeling. If you are using a cut-cell type of solver (e.g. Flow-3d or Phoenics) then you would designate the humans as blocked regions, but the base mesh would remain.