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3.0 Input Language

GnuRad uses an input language to create a model. The language has keywords to describe the various properties of the model. The keywords are listed below. They may be lower, mixed, or upper case.

Box
Bundle
Iterate
Media
Melement
Mode
Model
Particle
Seed
Wall
Welement
#

Separators Input data is separated by any of the following characters which are enclosed in single quotes: '','
':'
';'
'('
')'
'space'
'Carriage return'


Keyword Order Each keyword has it's own list of parameters and data associated with it. In regards to order, GnuRad expects to see the following order of keywords. Note, a decimal indicates that this keyword is either optional or only used with certain modes.

1) Mode
2) Bundle
2.1) {Seed}
3) Model
First box set (Denote by E1)
E1-1) Box
E1-2) Wall1 through 6
E1-2.1) {Welement}
E1-2.2) {Iterate}
E1-3) Media
E1-3.1) {Melement}
E1-3.2) {Iterate}
Second box set (Denoted by E2)
E2-1) Box
E2-2) Wall1 through 6
E2-2.1) {Welement}
E2-2.2) {Iterate}
E2-3) Media
E2-3.1) {Melement}
E2-3.2) {Iterate}
Next set, continue until all box are entered


Keyword Description

Box(bnum, Xdim, Ydim, Zdim)

bnum - The box number; this should be a positive integer value greater than zero. The elements must appear in sequential order.
Xdim - x axis dimension which coincides with the box coordinate system.
Ydim - y axis dimension which coincides with the box coordinate system.
Zdim - z axis dimension which coincides with the box coordinate system.


Bundle(value)

value - Value can have two possible choices. If GnuRad is in temperature mode, value is a positive floating point number greater than zero which represents the energy of a photon bundle per unit time. If GnuRad is in View factor/ Radiation exchange factor (Script F) mode, value is a positive integer number greater than zero which represents the number of bundles to send per unit area.



Iterate(maximum, percent, factor, qnet(i), ...qnet(nelements) )

maximum - The maximum number of iteration loops, an integer value. Note, setting maximum to a small value may prematurely stop convergence.
percent - The maximum error ratio specified in percentage.
factor - The iteration update factor, 1.0 is a nominal value.
qnet(i) - The final flux value the ith element should reach after iterating.



Media(bnum, Media keyword)

bnum - The box number containing the media.

Media keyword - The following are for use in the Temperature mode.
Media(element, clear)
Media(element, element, meshx, meshy, meshz, Ke, ssal, scatter)
{Melement Keyword must follow on the next line if element is used in Media}
Media(element,flux, flux, Ke, ssal, scatter)
Media(element,temp, temperature, Ke, ssal, scatter )
Media(element, unknown, meshx, meshy, meshz, Ke, ssal, scatter)
{Iterate Keyword must follow immediately if unknown is used}

Media keywords - View Factor or Radiation Interchange Factor Mode (RIF)
Media(element, participate, Ke, ssal, scatter)
Media(element, clear)

clear- Use when the Media is non participating.
element - Use when each media meshed element should have its own temperature or flux value.
flux - Energy per unit volume per unit time sent out by the media.
participate - The media participates in the radiation exchange factor calculation.
temp - Temperature of the media.
unknown - The temperature of the media is unknown.

Ke - Extinction coefficient
meshx - The number of meshed elements in the x direction.
meshy - The number of meshed elements in the y direction.
meshz - The number of meshed elements in the z direction.
scatter - Type of scattering choices are currently, "Isotropic".
ssal - Single scattering albedo. temperature - Media temperature.



Melement(value, first element property, .... last element property)
value - It can be flux or temp.
element property - Depending on value, it is either the energy per unit volume per unit time or the temperature.



Mode(mode)

mode - The execution mode, the two choices are, "Temperature " or "View". Temperature mode is for solving for temperatures and fluxes where View is solving for view factors or radiation exchange factors.


Model(num Boxes)

num Boxes - The number of boxes that build the model.


Particle(p1,p2,p3,p4,p5,p6)

p1- p6 Partial parameters, all are real values.

This keyword is to be used by future scattering models where the properties of the media's particles may need to be known. Please see the "Future Enhancement" section at the end of this manual for more detail.


Seed(unsigned int)

unsigned int - An unsigned integer value which seeds the random number generator. This Keyword is optional.




Wall(num, Wall keyword)

num - The wall number, an integer between one and six.

Wall keywords - The following are for use in the Temperature Mode
Wall(num,element, local meshx, local meshy)
{Welement Keyword must follow on the next line if element is used in Wall}
Wall(num,flux, flux, emissivity, reflectd, reflects )
Wall(num,join, jbox, jwall)
Wall(num,remove, far_temp)
Wall(num,temp, temperature, emissivity,reflectd, reflects)
Wall(num,unknown, local meshx, local meshy, emissivity, reflectd, reflects)
{Iterate Keyword must follow immediately if unknown is used}

Wall keywords - View Factor or Radiation Exchange Factor Mode
Wall(num,participate, emissivity)
Wall(num, receive,emissivity)
Wall(num, remove)
Wall(num, send, emissivity)

element - Divides the wall into a meshed wall where each element has it's own temperature or flux, emissivity, and reflectivity.
flux - Energy per unit area per unit time sent from the wall.
join - The wall joins two boxes. It becomes a virtual wall.
participate - The wall participates in the radiation exchange factor calculation.
receive - The receiving wall in the view factor or radiation exchange factor mode.
remove - The wall has been removed. It does not participate.
send - The sending wall in the view factor or radiation exchange factor mode.
temp - The initial temperature of the wall.
unknown - The temperature or flux in unknown.

emissivity - The emissivity of the wall.
far_temp - The outside blackbody temperature.
flux - The energy per unit area per unit time sent out by the wall.
jbox - The ID number of the box which is joined to wall.
jwall - The wall number of the jbox.
local meshx - The number of meshed units in the wall local x coordinate system.
local meshy - The number of meshed units in the wall local y coordinate system.
reflectd - The diffuse reflection component.
reflects - The specular reflection component.
temperature - The initial temperature of the wall.


Welement(value, [temp or flux, emissivity, reflectd, reflects ], ..... for all elements)

value - value is either "temp" or "flux".
temp or flux - The element's temperature or flux depending on value.
reflectd - The diffuse reflection component.
reflects - The specular reflection component.



# - Comment

If the '#' symbol is used in the input file, the rest of the line is considered to be comments.
output file already exists, it will be over written without warning.
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