<html>
<body>
<font face="Courier New, Courier">This is a part of the TYPE34 code
:<br>
...<br>
2000 CONTINUE<br>
<br>
GB=XIN(5)<br>
GD=XIN(4)<br>
GR=XIN(3)<br>
RHO=XIN(6)<br>
IF(VERSNUM.EQ.16) IncAng = XIN(7)<br><br>
<br>
OUT(2) = GB*FI<br>
OUT(3) = GD*VFSky<br>
OUT(4) = RHO*GR*VFGround<br>
<x-tab> </x-tab>IF
(OUT(2).LT.0.d0) OUT(2)=0.d0<br>
<x-tab> </x-tab>IF
(OUT(3).LT.0.d0) OUT(3)=0.d0<br>
<x-tab> </x-tab>IF
(OUT(4).LT.0.d0) OUT(4)=0.d0<br>
OUT(1) = OUT(2)+OUT(3)+OUT(4)<br>
OUT(5) = FI<br>
<x-tab> </x-tab>OUT(6) =
RepVFSky<br>
<x-tab> </x-tab>OUT(7) =
RepVFGround<br>
<x-tab> </x-tab>
GTOT=(GB+GD*0.5d0+RHO*GR)<br>
<x-tab> </x-tab>OUT(11) =
1<br>
IF (GTOT.GT.0.d0) OUT(11) =
1-OUT(1)/GTOT<br>
<x-tab> </x-tab>
IF(VERSNUM.EQ.16) OUT(12) = IncAng<br>
<br>
RETURN 1<br>
</font>...<br><br>
<br>
So, you see that GD = XIN(4) and that OUT(3) = GD * VFSky<br>
VFSky is the sky view factor of the receiver and OUT(3) supposes to be
the sky diffuse solar radiation on receiver.<br>
Look at equation (5.7.4.1) in TRNSYS Manual p. 5-226, you see that the
diffuse part of the total solar radiation incident on the receiver is
composed by the diffuse component of solar radiation incident on the
receiver surface (and not the horizontal diffuse radiation) * the sky
view factor of the receiver. <br>
You meet again equation (5.7.4.1) in the expression :
<font face="Courier New, Courier">OUT(1) = OUT(2)+OUT(3)+OUT(4)<br>
</font>where :<br>
<font face="Courier New, Courier"><x-tab>
</x-tab>OUT(2) =
GB*FI<br>
OUT(3) = GD*VFSky<br>
OUT(4) = RHO*GR*VFGround<br><br>
</font>That's why I'm almost sure that Xin(4) supposes to be diffuse
radiation on the receiver surface.<br><br>
Regards,<br>
Christophe.<br><br>
<br>
Christophe, Fernando et al,<br><br>
<blockquote type=cite class=cite cite=""><i>In both cases (a) and (b) I
suppose that the sky diffuse radiation input<br>
is always the input number 4 of type34. The label in the proforma is<br>
somewhat error prone (it says “sky diffuse on the horizontal”).<br>
</i> <br>
I think you’re right !! There’s an error in the TYPE 34 proforma :
input(4) has to be the diffuse radiation <u>on surface</u> and not the
horizontal diffuse radiation. You can check it in the TYPE34 source
code.</blockquote><br>
This is NOT an error in the Type34 proforma. Type34 takes the diffuse
radiation on the <i>horizontal </i>surface and the beam radiation on the
shaded opening. <br><br>
If you could please point out the spot in the Type34 code that leads you
to believe that the model expects diffuse radiation on the shaded
surface, I would be happy to clarify further.<br><br>
Regards,<br>
David<br><br>
<x-sigsep><p></x-sigsep>
===========================<br>
ENERTECH<br>
F-26160 FELINES SUR RIMANDOULE<br>
tel-fax : 04 75 90 18 54<br>
Email : sidler@club-internet.fr<br>
Web :
<a href="http://perso.club-internet.fr/sidler" eudora="autourl">
http://perso.club-internet.fr/sidler<br>
</a>================================</body>
</html>