Re: [EnergyPlus_Support] Re: temperature gradient

[Lixing Gu <gu@xxxxxxxxxxxx>]

Neslihan:

My answers are below your questions.

----- Original Message ----- 
From: "neslihanturkmenoglu" <neslihanturkmenoglu@xxxxxxxxx>
To: <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Wednesday, April 16, 2008 6:23 AM
Subject: [EnergyPlus_Support] Re: temperature gradient


> Hi Lixing
>
>
> I calculated wind speed profile exponent with the values  got from
> wind tunnel measurements in front of the scale model.
> In order to understand,  I change the values one by one in weather
> station object or site atmospheric variation object, nothing changed
> in the results of airflow volume flow rate 2 to 1.
> The only change occured when I enter my wind speed profile exponent
> to airflow network-site wind conditions object.
>
Your observation is correct. The wind speed calculation in the airflow 
network model is independent of inputs of weather station object and has its 
own inputs.

> I understood that one exponent is for weather site conditions,
> the other exponent is for building site conditions.Why is there the
> third one with another default value in airflow network site wind
> conditions?
>
The field of Wind velocity profile exponent in the AIRFLOWNETWORK SIMULATION 
object and the field of Exponent of Wind Velocity Profile in the 
AIRFLOWNETWORK:MULTIZONE:SITE WIND CONDITIONS object are used for wind speed 
calculation. Could you let me know which is the third one specifically?

> when I compare the results of energyplus with my manually calculated
> volume flow rates, they are not the same. So in order to define the
> wind tunnel conditions in Energyplus, what do you suggest me to do?
>

What is your definition of manual calculation results? If you compare your 
testing results, you have to ensure the input values used in the EnergyPlus 
match your testing conditions. I have no knowledge of convertion from wind 
tunnel conditions to EnergyPlus inputs.

> And which velocity should I enter to design object wind velocity
> field- u mean calculated from measured data in front of the scale
> model or the wind tunnel's 2.5 m/s Gradient velocity %10 Motor
> velocity.
>
When you got the calaculated wind velocity using the scale model, the 
velocity used in weather data should be at the height consistent with the 
input value of Reference height for recorded wind data in the AIRFLOWNETWORK 
SIMULATION object.

> I hope you answer in a short time.
> thank you very much
> 

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