[Fwd: Re: FW: Re: [TRNSYS-users] Bug in TYPE74]

[David Bradley [SEL]]

Dear Fernando,
  It is inefficient to recalculate the characteristic parameters at 
every iteration (as is done in the component) because if you only have 
one instance in the input file, then there is no need to recalculate 
those values at each time step. You need only read the parameters once 
and then calculate those lines between the ENDIF and line 60 once. If 
those lines were brought inside the ENDIF then you would also want to 
copy the lines up to the section between

      !initialize storage variables
        RHOD=-1.
      EFFD=0.
        TALN=TAU_ALPHA(NG,EFFD,XKL,RI,ALF,RHOD)
      stored(1) = RHOD
      stored(2) = TALN
      CALL setStorageVars(NStorage,stored,INFO)

and

      !set the outputs to 0
        OUT(1) = XIN(1) 
      OUT(2:NO) = 0.d0 !zero remaining outputs
        RETURN 1         !the first timestep is for initialization - exit.

as well because if there is only one instance of Type74, and if the 
ENDIF had been moved down to line 60 then those lines would never be 
executed because INFO(1) would always equal IUNIT. If you have an input 
file that is giving you results that you don't understand and you have 
tracked it to Type74, please feel free to send it to me. You may be 
right that there is a problem although I do not see one from looking at 
the structure of the code in there.
Kind regards,
  David

Fernando Domínguez Muñoz wrote:

>Dear David,
>
>the (INFO(1).NE.IUNIT) check is right. The problem comes from the end
>point of the IF statement:
>
>c      IF(INFO(1).NE.IUNIT) THEN
>        !recall the UNIT and TYPE number
>        IUNIT = INFO(1)
>	ITYPE = INFO(2)
>        !read parameter values
>	NS     = JFIX(PAR(1)+0.1)
>        XNS    = DBLE(NS)
>
>         ..........
>         ..........
>
>        RI     = PAR(12)
>        XKL    = PAR(13)
>
>c	ENDIF  <---------- THIS
>
>C    RETRIEVE STORED VARIABLES
>      CALL getStorageVars(NStorage,stored,INFO)
>
>I think that the end point of this loop must be the line number 60,
>where the program starts reading the inputs. But, the characteristic
>parameters of the unit are re-calculated on every interation, and
>consequently its values turn incorrect.
>
>Best regards
>
>Fernando.
>
>  
>
>>Dear Fernando,
>> The line
>>
>>IF(INFO(1).NE.IUNIT) THEN
>>
>>is correct. The point of the line is to handle the case in which there 
>>is more than one instance of Type74 in the simulation. The variable 
>>INFO(1) is always the current instance's UNIT number (specified in the 
>>input file). At each time that the Type is called, the value of INFO(1) 
>>is stored as a local variable. In this way, if ever INFO(1) and IUNIT do 
>>not have the same value, then it can only be because a different 
>>instance of the component has been simulated. If a different instance 
>>has been simulated, then the component's parameters should be reread and 
>>reset to local variables.
>>
>>In December 2004, a bug fix was made in that component. If your version 
>>does not have the comment:
>>
>>C  12/02/2004 - JWT - Fixed an error with storing variables and added 
>>the first call to Tau_Alpha
>>
>>in the "Revision History" near the top of the file Type74.for then you 
>>should contact your distributor to get the latest version.
>>Kind regards,
>> David
>>
>>Fernando Domínguez Muñoz wrote:
>>
>>    
>>
>>>Dear all,
>>>
>>>I think I have found a bug in TYPE74 (parabolic concentrator solar
>>>collector).
>>>
>>>Where says (Line 207):
>>>
>>>     IF(INFO(1).NE.IUNIT) THEN
>>>
>>>Should said:
>>>
>>>     IF(INFO(1).NE.IUNIT) GO TO 60
>>>
>>>Best regards.
>>>
>>>Fernando Domínguez Muñoz
>>>University of Málaga (Spain)
>>>_______________________________________________
>>>TRNSYS-users mailing list
>>>TRNSYS-users at engr.wisc.edu
>>>https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
>>> 
>>>
>>>      
>>>
>_______________________________________________
>TRNSYS-users mailing list
>TRNSYS-users at engr.wisc.edu
>https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
>  
>
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