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Contributor
anasabukhadra
Posts: 16
Registered: ‎10-18-2013

Natural ventilation

493 Views, 24 Replies
10-18-2013 12:31 AM

Hello,

 

I am an architecture student, and I am working on a passive cooling, naturally ventilated design. I am still a beginner with Simulation CFD. I was trying to see what my options are with my project. I basically want to simulate how the air enters the room from the outside, how it moves inside and how the temperature changes. I know it sounds pretty simple. Are there any videos or tutorials to help with that? Question 2, does Simulation CFD use weather files or do I always have to specify the weather conditions and so.

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Product Support
wildej
Posts: 961
Registered: ‎08-25-2011

Re: Natural ventilation

10-18-2013 02:31 AM in reply to: anasabukhadra

Hi,

 

You are going to need to set this up using CFD Boundary Conditions - what is usually contained within weather files?

 

Best bet is to model the building on the ground and also add an air-volume around it - then you can apply flow and temperaure conditions to the inlet and a P=0 at the outlet of the air volume (to let the air escape again).

 

This would be a good starting point I think.

 

Kind regards,

Jon

 



Jon Wilde
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Contributor
anasabukhadra
Posts: 16
Registered: ‎10-18-2013

Re: Natural ventilation

10-18-2013 08:08 AM in reply to: wildej

Thank you for your prompt response. I'll start with this today and I will see where I get and I will ask again if I get stuck with something.

 

Weather files are basically used for energy simulation software such as eQuest. Let's say that for example I want to simulate a building in San Diego, CA. all I have to do is to import the weather file which contains all the climatic data for San Diego through out the year and the software would use it to smulate different  designs, So you wouldn't need to specify any climatic conditions and the software would give you results for the different months/days/hours.

 

Thanks again

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Product Support
wildej
Posts: 961
Registered: ‎08-25-2011

Re: Natural ventilation

10-18-2013 10:01 AM in reply to: anasabukhadra

Ah OK, makes sense.

 

Just be sure to start simple - steady state only, no radiation and then go from there once that is working.

 

Feel free to post some images of the setup/results if you need more help.



Jon Wilde
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Contributor
anasabukhadra
Posts: 16
Registered: ‎10-18-2013

Re: Natural ventilation

10-24-2013 08:43 PM in reply to: anasabukhadra

Hello again,

 

I would appreciate your help answering a few questions. I just need to know if Simulation CFD has the potential of doing what I'm going to show and if you could give me a few tips. 

 

Image number one shows simplified drawings of what I am working on. a small space that is naturally ventilated, with an out door air inlet and outlet. I have a facade system I am working on, which consists of a perforated external skin and a glazed layer behind it.

 

Image number 2 shows how the air is expected to move considering that the top and bottom between the building and the skin are blocked). The air is going to penetrate through the external skin, move down towards the opening to go up again towards the window and leave the space from the outlet).

 

What I need to do is to study the air flow and speed, change in temperature, and thermal comfort inside the space. Would that be possible?  Can you give me some tips please?

 

I would really appreciate your help as I am kind of stuck with this.

 

Thank you!

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Contributor
anasabukhadra
Posts: 16
Registered: ‎10-18-2013

Re: Natural ventilation

10-24-2013 08:43 PM in reply to: anasabukhadra
 
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Active Contributor
ajay.s
Posts: 51
Registered: ‎08-13-2013

Re: Natural ventilation

10-24-2013 10:10 PM in reply to: anasabukhadra

Dear Architect,

 

Based on your previous post and uploaded images, Yes you can determine "air flow and speed, change in temperature, and thermal comfort inside the space" but as a beginner, you can take this(Solve) as a 3 case:

 

1. Fluid Flow - to know air flow & speed inside occupant space

2.  Fluid Flow + Heat Trasnfer - to additionally find, delta Temperature 

3. Fluid Flow + Heat Transfer + Radiation - additionally, to extract weather conditions, solar loading & to extract thermal comfort.

 

Do, each step exclusively and understand it & proceed further. By completion of all 3 seperate steps you will be confident of using all together & know how simple to use this Tool. 

 

All d best.

 

 

Regards,

Ajay.S

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Contributor
anasabukhadra
Posts: 16
Registered: ‎10-18-2013

Re: Natural ventilation

10-24-2013 10:38 PM in reply to: ajay.s

Thank you so much for your prompt response. I just want to make sure that the software will be satisfying my needs before I start working on it. I also want to ask one last question before I start; let's say that I have a water medium or moisturised medium on the external skin, would the software also determine the change in temperature after the air penetrates through this moisturised medium?  To simplify the question please look at the image attached with this message.

 

Thank you so much again and your help is much appreciated.

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Active Contributor
ajay.s
Posts: 51
Registered: ‎08-13-2013

Re: Natural ventilation

10-24-2013 10:53 PM in reply to: anasabukhadra

Dear,

 

These links can be of much help,

 

http://help.autodesk.com/cloudhelp/2014/ENU/SimCFD/files/GUID-599627EC-C556-42DC-9415-BB50BFCBFFC8.h...

 

http://help.autodesk.com/view/SCDSE/2014/ENU/

My suggestion, is to start working with the Tool and explore your requirment, its very simple to use and understand.  

 

All the best.

 

Kind Regards,

Ajay.S

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Contributor
anasabukhadra
Posts: 16
Registered: ‎10-18-2013

Re: Natural ventilation

10-24-2013 10:55 PM in reply to: anasabukhadra

Wonderful. I did play with it a bit and explored a few stuff but just waned to make sure. Thank you so much sir and I ppreciate your efforts.

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