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ajay.s
Posts: 51
Registered: ‎08-13-2013
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Internal Fluid Volume creation for Revit models

336 Views, 9 Replies
09-20-2013 12:03 AM

Dear CFD Experts,

 

I am interested in creating Internal Fluid Volume for Revit models eg: House. If I am interested in analysing internal flow & Occupany comfort inside a house/building, CFD requires Internal Fluid Volume. Even though, my model is closed one, CFD did not generate a fluid volume inside while opening.

 

Void fill tool did not help me out.

Can you guide me through steps for creating INTERNAL FLUID VOLUME inside house/building (multi-floors) using CFD tool. 

 

Many Thanks

 

Regards,

AJay

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wildej
Posts: 872
Registered: ‎08-25-2011

Re: Internal Fluid Volume creation for Revit models

09-20-2013 12:55 AM in reply to: ajay.s

The likelehood here is that the house is not 100% sealed - that or you have some complex geometry/very small gaps inside preventing CFD from creating the volume.

 

To check the former, place the entire model in an air box (using the Geometry tools within CFD) and apply a 1psi pressure internally and a P=0 somewhere on the external wall of the air domain. Mesh only the air.

When you run this, you should find that CFD helps you highlight a leakage path - usually an ISO surface is most useful here.

 

I hope this helps.

 

Regards,

Jon



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

Re: Internal Fluid Volume creation for Revit models

09-20-2013 02:08 AM in reply to: wildej

Dear Jon,

 

Thanks for the quick reply.... nice idea to test for leakage... but my model do not have leakage and yet could not generate any fluid volume.... consider scenario working in AEC sector with several revit models dialy and I need to perform internal analysis ... how can I generate fluid region for my models ?

I have tried a rectangular box from fusion, but CFD did not build/generate any fluid region for it internally.....

pls guide me in this regard

 

Thanks in advance

 

Ajay

cfd house

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Product Support
wildej
Posts: 872
Registered: ‎08-25-2011

Re: Internal Fluid Volume creation for Revit models

09-20-2013 02:12 AM in reply to: ajay.s

Hi Ajay,

 

Did you run a test with a 0 psi somewhere on an internal wall and a P=0 on the outer domain? 

It looks like you have some flow here... although I cannot tell if this is because you have an external flow set on the main air domain.

 

If you build the external domain, as soon as you hide it (if it is joined with the internal through a leakage path) then the internal would also disappear..

 

Could you share a CFZ file?

 

Thanks,

Jon



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

Re: Internal Fluid Volume creation for Revit models

09-20-2013 03:05 AM in reply to: wildej

wildej wrote:

Hi Ajay,

 

Did you run a test with a 0 psi somewhere on an internal wall and a P=0 on the outer domain? 

It looks like you have some flow here... although I cannot tell if this is because you have an external flow set on the main air domain.

 

If you build the external domain, as soon as you hide it (if it is joined with the internal through a leakage path) then the internal would also disappear..

 

Could you share a CFZ file?

 

Thanks,

Jon



wildej wrote:

Hi Ajay,

 

Did you run a test with a 0 psi somewhere on an internal wall and a P=0 on the outer domain? 

It looks like you have some flow here... although I cannot tell if this is because you have an external flow set on the main air domain.

 

If you build the external domain, as soon as you hide it (if it is joined with the internal through a leakage path) then the internal would also disappear..

 

Could you share a CFZ file?

 

Thanks,

Jon




Dear Jon,

 

I have attached the CFZ file, pls guide me through internal fluid volume creation.

 

Cheers,

Ajay

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Product Support
wildej
Posts: 872
Registered: ‎08-25-2011

Re: Internal Fluid Volume creation for Revit models

09-20-2013 03:34 AM in reply to: ajay.s

Hi Ajay,

 

Just an FYI - this cannot be done in CFD and must be done automatically when you bring the model through from Revit.

I would also strongly advise you to create the external void in Revit, as we will have a gap underneath the building if we use the CFD tool - typically not ideal to have a floating building :smileyhappy:

 

Take a look at the windows too, can you make them simpler? All the detail just adds to the mesh - is it necessary?

 

I can also see a hole which would prevent CFD from creating the internal part:

 

Hole.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cheers,

Jon



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

Re: Internal Fluid Volume creation for Revit models

09-20-2013 04:09 AM in reply to: wildej
Dear Jon,

Yes u r right in this regard.... with this house model from revit !!!
But I was trying several other models (even CFD tutorial models eg: Solar heating model (UGNX) into CFD, but could not get the fluid volume unless MODELED IN CAD...
Can you provide an example in which CFD creates Fluid volume internally without having in CAD....
it would be of great help.

Thanks in advance

Regards
Aj
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Product Support
wildej
Posts: 872
Registered: ‎08-25-2011

Re: Internal Fluid Volume creation for Revit models

09-20-2013 04:46 AM in reply to: ajay.s

The process should be simple: bring through any hollow and 100% sealed model from Revit into CFD and we will fill it for you.

 

As an example I have uploaded a rvt file that is hollow and sealed. Read this into CFD and you will see what I mean - the output bar will report back saying how many additional parts were created :smileyhappy:

Here there are 3 and you will find them at the bottom of the list of materials in the Design Study Bar, just called 'Volume'

 

I hope this helps clarify things for you.

 

Cheers,

Jon



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

Re: Internal Fluid Volume creation for Revit models

09-20-2013 05:28 AM in reply to: wildej
Dear Jon,

Yes its clear now and Thank you so much in sending the model with clarity.
Good job, highly appreciated.

Many Thanks

Cheers,
Ajay
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Product Support
wildej
Posts: 872
Registered: ‎08-25-2011

Re: Internal Fluid Volume creation for Revit models

09-20-2013 05:33 AM in reply to: ajay.s

Hi Ajay,

 

Not a problem at all, best of luck with your model!

 

Kind regards,

Jon



Jon Wilde
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