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RE[3]: FW: Re: [TRNSYS-users] Bug in TYPE74
Dear David,
Look at the sentence ALF=ALF*RHOEFF, just before line 60. This is the
problem. As the program executes it at every iteration, the value of ALF
changes incorrectly:
ALF=ALF*RHOEFF
ALF=ALF*RHOEFF*RHOEFF ......
The best way to fix this bug is:
ALF=par(10)*RHOEFF
Yesterday I fixed it in the following way:
IF(INFO(1).EQ.IUNIT) GO TO 60
IUNIT=INFO(1)
*** Parameter reading and calculations ****
At TIME=TIME0, IUNIT=0
(Sorry, but I did not explain the problem rightly in the former e-mail)
Best regards
Fernando.
>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@engr.wisc.edu
>>>>https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
>>>>
>>>>
>>>>
>>>>
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>>
>>