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Re: [EnergyPlus_Support] Discharge Coefficient
Ana Paula:
My suggestion is that you may need to understand how the opening factor is
determined first (on pages 639-644 in Input Output Reference). Then opening
area and discharge coefficient are calculated based on the opening factor
using linear interpolation. The opening area calculation is described in
Figure 83 on page 659 in the Input Output Reference. Equations on page
382-383 in the Engineering Reference are used to calculate airflows.
The examples I have are example input files you have after installing
EnergyPlus.
Lixing
----- Original Message -----
From: "Ana Paula Melo" <apaula_melo@xxxxxxxxx>
To: <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Wednesday, April 16, 2008 10:25 AM
Subject: Re: [EnergyPlus_Support] Discharge Coefficient
> Hi Lixing,
> I did not understand so much your example. I have been study the
> Engineering
> Reference on page 383 but it is still not so clear for me yet. My problem
> is when the window/door are open.
> I changed some values and I noticed that the air flow has changed. But I
> really want to know how to calculate it correctly.
> Can you send me an example of it???
> Thanks so much,
> Ana Paula.
>
>
> Lixing Gu <gu@xxxxxxxxxxxx> wrote: Ana:
>
> The AIRFLOWNETWORK:MULTIZONE:COMPONENT DETAILED OPENING object has two
> ways
> to calculate airflow across the component: window open and close. When the
> window is close, it only uses two fields to calculate the airflow: "Air
> Mass
> Flow Coefficient When Opening is Closed" and "Air Mass Flow Exponent When
> Opening is Closed", regardless of other inputs, including discharge
> coefficients.
>
> When the window is open, the discharge coefficient is used to calculate
> airflow. The discharge coefficient used in the calculation is linear
> interpolation based on the window opening factor. For example, the window
> opening factor is 0.5. The input of discharge coefficient for opening
> factor
> #1is 0.2 at Opening factor #1=0, and the input of discharge coefficient
> for
> opening factor #2 is 0.4 at Opening factor #2=1. The discharge coefficient
> is 0.3. The use of discharge coefficient is given in the Engineering
> Reference on page 383.
>
> The window opening factor is given at the report variable: Window/Door
> Venting Opening Factor. The zero value represents window is close. The
> opening factor determination/calculation is described in detail on pages
> 639-644 in Input Output Reference Please add one more report variable if
> the
> opening factor is not in the output list. If you still have problem,
> please
> upload the file.
>
> Thanks.
>
> Lixing Gu
> ----- Original Message -----
> From: "Ana Paula Melo" <apaula_melo@xxxxxxxxx>
> To: "EnergyPlus Support" <energyplus_support@xxxxxxxxxxxxxxx>
> Sent: Monday, March 31, 2008 3:54 PM
> Subject: [EnergyPlus_Support] Discharge Coefficient
>
>> Hi,
>>
>> I would like to know more about the follow field: Discharge Coefficient
>> for Opening Factor #1, located in the follow AirflowNetwork object:
>> AirflowNetwork:Multizone:Component:Detailed Opening.
>>
>> As this field is related to the discharged coefficient I believed that
>> its value in the air flow calculation has a special significant during
>> the
>> simulation. The manual indicates that I can use a value greater than 0 or
>> less than 1, and the default value being 0.001. But, during my simulation
>> I changed this value for: 0.01; 0.1; 0.6;1 and the results of the air
>> change rate have not changed.
>>
>> I would like to know with what parameters this field is exactly related.
>>
>> Thank you so much,
>>
>> Ana Paula.
>>
>>
>> ---------------------------------
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>> ------------------------------------
>>
>> The primary EnergyPlus web site is found at:
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>>
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>>
>> Attachments are not allowed -- please post any files to the appropriate
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>>
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>>
>>
>>
>>
>
>
>
>
>
>
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> [Non-text portions of this message have been removed]
>
>
> ------------------------------------
>
> The primary EnergyPlus web site is found at:
> http://www.energyplus.gov
>
> The group web site is:
> http://groups.yahoo.com/group/EnergyPlus_Support/
>
> Attachments are not allowed -- please post any files to the appropriate
> folder in the Files area of the Support Web Site.
>
> EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the
> Documentation link and press the "search" button.
> Yahoo! Groups Links
>
>
>
>
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