Card 6j - View Factor Merging

L

L is the code VFMERGE (or 18)

N1S, INC1, N1N, INC2, N2N

N1S is the starting element for Option 2. Option 2 creates N2N Cards 6j, each starting with an N1 element incremented by INC2. Each Card 6j contains N1N elements, incremented by INC1. The generated Cards have the format:

 VFMERGE, N1S, N1S+INC1, ....N1S+(N1N–1)*INC1
 VFMERGE, N1S+INC2, N1S+INC2+INC1,....N1S+INC2+(N1N–1)*INC1
 .
 .
 VFMERGE, N1S+(N2N–1)*INC2,.....N1S+(N2N–1)*INC2+(N1N–1)*INC1
 

NAME1, NAME2

NAME1 and NAME2 are group names.

NM

NM is an element number.

Code example

 VFMERGE 1 2 3 4          
 VFMERGE,GENER,1,1,5,10,2 INTO 1.
 $ ELEMENTS 2,3, AND 4 MERGED INTO 1.
 $ ELEMENTS 2,3,4,5 MERGED
 $ ELEMENTS 12,13,14,15 MERGED INTO 11.
 

Notes

• For Option 1, Card 6j merges the view factors, solar view factors, albedo factors, and Earth view factors of elements NM, NN2, NN3,... A new element NM is created, with an area equal to the sum of the areas. The radiative surface properties are set to the area–averaged values.
• For Option 3, the elements of NAME1 are merged with the starting element of NAME1. The starting element is the first element defined on the Card 9 group name NAME Card, or the lowest element number defined.
• For Option 4, all the elements of group NAME2 are merged into element NM. A new element NM is created, with an area equal to the sum of the areas. The radiative surface properties are set to the area–averaged values.
• Card 6j differs from Card 7 in that element merging is performed for the radiative properties only. This is useful for reducing the size of the view factor matrix to be inverted by the GRAYB module. However, it results in less accurate radiative conductances.
• Corresponding Card 7 Merging Cards should be present whenever Card 6j is used, to merge the non-radiative model parameters.
• The use of the Card 7 Merging Card is recommended instead of Card 6j.