Re: Internal header pressure drop calculation (TYPE 45)

[Graham Morrison <g.morrison@xxxxxxxxxxx>]

Dear Jaun

There is a mistake in the TRNSYS manual.  The S2 term 
should  be  (NR-i+1)^2/NR^2.
I cannot find the original reference for this, it may have come from Jones 
& Lior "Isothermal flow distribution in solar collectors and collector 
manifolds"  1978. (have lost the rest of the reference).
I have some original workings that i could send if you are interested.

Regards

Graham Morrison


At 06:09 AM 19/02/2004, you wrote:
> Dear TRNSYS users,
>
> TYPE 45 calculates the pressure drop in the collector headers internally if
> experimental data is not available. The procedure is explained on page 4.2.2-5
> of the TRNSYS manual.  I managed to derive the term S1 assuming equal mass 
> flow
> in each header (I found S1*A11 to be the pressure drop in the lower header).
> What I don't seem to grasp is the S2 term and the equation 4.2.2.9, which
> differs from what is in the TYPE 45 source code. This formula (in the manual,
> not in the source code) obviously presents a problem since the added terms 
> in it
> have different units. I would like to know if there is any available reference
> (book, article, whatever) that explains this calculation procedure a 
> little more
> explicitly.
>
> Best Regards,
> Juan Pablo de L. C. Salazar
>
>
> ----------------------------------------------------------------
> LABSOLAR/NCTS - EMC - UFSC

Graham Morrison



Professor of Mechanical Engineering
School of Mechanical & Manufacturing Engineering
The University of New South Wales
Sydney  Australia 2052

Phone  +61 2  93854127
Fax       +61 2 96631222
g.morrison@xxxxxxxxxxx
<http://www.mech.unsw.edu.au/mech/profiles/morrison.htm>http://www.mech.unsw.edu.au/mech/profiles/morrison.htm 


Solar Thermal Energy Laboratory
<http://www.mech.unsw.edu.au/mech/laboratories/l_solar.html>http://www.mech.unsw.edu.au/mech/laboratories/l_solar.html 



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