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Homework Help: Help with view factors

  1. Apr 16, 2015 #1
    1. The problem statement, all variables and given/known data
    I found the values ##F_{3\rightarrow(1+2)}=0.32## and ##F_{1\rightarrow3}=0.25##
    I now want to find ##F_{2\rightarrow3}##

    2. Relevant equations
    Reciprocity relation
    ##A_iF_{i\rightarrow j}=A_jF_{j\rightarrow i}##

    3. The attempt at a solution
    Using the reciprocity relation to find ##F_{(1+2)\rightarrow3}##
    ##A_3F_{3\rightarrow(1+2)}=A_{(1+2)}F_{(1+2)\rightarrow3}##
    ##3(0.32)=6F_{(1+2)\rightarrow3}##
    ##F_{(1+2)\rightarrow3}=0.16##

    Using that to find ##F_{2->3}##:
    ##F_{1\rightarrow3}+F_{2\rightarrow3}=0.16##
    ##0.25+F_{2\rightarrow3}=0.16##
    ##F_{2\rightarrow3}=-0.09##

    But I get a negative value
     

    Attached Files:

  2. jcsd
  3. Apr 16, 2015 #2

    haruspex

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    I don't think ##F_{(1+2)\rightarrow3}=F_{1\rightarrow3}+F_{2\rightarrow3}##
     
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