More than Two Materials in Enclosures - How to Model?

[flash3780]

I have several enclosures in my model that have more than 2 materials - each with different emissivities. I was wondering what the appropriate means of modeling this is. I've tried the general radiosity solver, but I get the following error when I try to input more than two radiating surfaces in an enclosure:

*** ERROR *** CP = 227.219 TIME= 15:59:34
The Nlist field of ( RAD_ ) on the SF command is invalid. Only the
labels of ALL,blank,P,P51x, or a COMPONENT name are allowed. The SF
command is ignored.

My input is below. Any suggestions? Thanks in advance for the help.

/prep7
sf,RAD_SURF_1A,rdsf,0.200,1		! Nickel 0.05-0.86, ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_1B,rdsf,0.200,1		! Nickel 0.05-0.86, ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
spctemp,1,850

sf,RAD_SURF_2A,rdsf,0.535,2 	! Zirconium (0.62-0.45), ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_2B,rdsf,0.441,2 	! Type 304SS ([URL unfurl="true"]http://www.nordicinnovation.net/nordtestfiler/rep570.pdf)[/URL]
sf,RAD_SURF_2C,rdsf,0.150,2		! Aluminum (0.11 - 0.19), ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
spctemp,2,134

sf,RAD_SURF_3A,rdsf,0.200,3		! Nickel 0.05-0.86, ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_3B,rdsf,0.535,3		! Zirconium (0.62-0.45), ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_3C,rdsf,0.950,3		! Microsil Insulation ([URL unfurl="true"]http://www.zircarceramics.com/pages/microporusinsulation/microporous.htm)[/URL]
sf,RAD_SURF_3D,rdsf,0.900,3		! Fiberfrax, ([URL unfurl="true"]http://www.fiberfrax.com/files/Fiberfrax-Durablanket-Mat.pdf)[/URL]
sf,RAD_SURF_3E,rdsf,0.150,3		! Aluminum (0.11 - 0.19), ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_3F,rdsf,0.001,3		! Blockoff Shells
spctemp,3,29.04

sf,RAD_SURF_4A,rdsf,0.535,4		! Zirconium (0.62-0.45), ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_4B,rdsf,0.400,4		! Nickel 0.05-0.86, ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
spctemp,4,950

sf,RAD_SURF_5A,rdsf,0.150,5		! Aluminum (0.11 - 0.19), ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_5B,rdsf,0.535,5		! Zirconium (0.62-0.45), ([URL unfurl="true"]http://www.omega.com/temperature/z/pdf/z088-089.pdf)[/URL]
sf,RAD_SURF_5C,rdsf,0.950,5		! Microsil Insulation ([URL unfurl="true"]http://www.zircarceramics.com/pages/microporusinsulation/microporous.htm)[/URL]
spctemp,5,150

stef,5.67e-8
toffst,273.15
hemiopt,10
tunif,500

/solu
rsymm,,0,y
rsymm,,0,z
rsurf

 

[flash3780]

Nevermind, dumb dumb dumb mistake on my part. Left the underscore off of my named selections (components) in Workbench. So, I sent ANSYS off looking for a component that didn't exist. I suppose that I just had to sleep that one off over the weekend.

Gee, in that context the error message makes sense, eh?

Well, if anyone needs an example of using the radiosity solver in ANSYS, see above.

Step 1: Define radiating faces as nodal components (i.e. named selections)
Step 2: Apply radiation using the SF command; set the emissivity and the associated enclosure for each surface
Step 3: Set the space temperature for the solver to radiate to through any holes or in the enclosure (can also use SPCNODE)
Step 4: Set the Stephan-Boltzmann constant, offset to absolute zero, hemiopt, and tunif.
Step 5: Enter solution, create symmetry conditions if they exist or decimation if desired, and mesh the surfaces with SURF252 elements.