Re: [TRNSYS-users] Stratification with Trnflow

[jeannieboef <jeannieboef@googlemail.com>]

I'm not aware of any model that can predict this scenario well, except  
CFD. You have to consider the convectional air flows along cold or hot  
exterior vertical surfaces and "mix up" your stradified air. You also  
have to consider the pleums around warm objects and persons. You also  
have to consider where air infiltrates at low and high levels.

You need a air node at all the wall surfaces at low level and high- 
level. I've seen a COMIS modelling attempting something like this.

I have the same problem. I'm trying to apply the 3-node displacement  
Muntz model (which is conceived for interior office spaces) to a huge  
factory hall.

Sent from my iPhone

On 25.04.2012, at 13:27, Hannes Oppeel <hoppeel@hotmail.com> wrote:

> Hi all!
>
> I'm currently modeling a church with multiple airnodes to evaluate  
> the stratification when the church is heated.
> All the airnodes are connected through ducts with very large  
> sections because a horizontal large opening would only simulate the  
> airflow in 1 direction.
> The air heating system is modelled with a fan-airlink between an  
> auxiliary node, where the inlet temperature is fixed to 21°, and the 
>  lowest airnode.
>
> The problem is that al the airnodes are increasing equally and at  
> with the same speed, while stratification normally would result in a  
> higer temperature in the higher airnodes.
> How can I fix this? Is there another way I could model the air  
> heating system?
>
> Many thanks
> Hannes Oppeel
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