Settings for modeling thermal radiation between surfaces
surfaceToSurfaceSettings object contains
information about the parameters for thermal radiation analysis between surfaces without
conductive media. The settings include all defined enclosures, names of enclosures currently
participating in radiation analysis, and computed view factors.
fem as both the
input and output argument to assign the resulting
surfaceToSurfaceSettings object to the
property of the specified model.
ViewFactors — Computed view factors
This property is read-only.
Computed view factors, stored as a numeric matrix. Computing view factors involves determining which mesh facet on the boundary sees which other facets, including the effect of shadowing. The toolbox uses ray tracing to determine shadowing, while it uses the double area integral method to compute the view factor itself.
Enclosures — Enclosures for surface-to-surface radiation analysis
Enclosures for surface-to-surface radiation analysis, stored as a dictionary with
string keys and
enclosureDefinition values. Each
enclosure is a group of surfaces between which heat transfer occurs due to radiation
without conductive media.
ParticipatingEnclosures — Names of enclosures participating in radiation analysis
string | vector of strings
This property is read-only.
Names of enclosures participating in radiation analysis, stored as a string or a vector of strings.
Specify Radiation Parameters
Specify radiation parameters for heat transfer between two parallel plates.
Create the geometry representing two parallel plates of the same dimensions. The distance between the plates is 0.4 m.
dist = 0.4; W = 0.05; L = 0.5; H = 0.5; R1 = [3 4 0 W W 0 0 0 L L]; R2 = [3 4 W+dist 2*W+dist 2*W+dist W+dist 0 0 L L]; geom2D = fegeometry(decsg([R1(:) R2(:)], ... 'R1+R2',[char('R1')' char('R2')'])); geom3D = extrude(geom2D,H); pdegplot(geom3D,FaceLabels="on",FaceAlpha=0.3)
Create a finite element model for thermal analysis and include the geometry.
fem = femodel(AnalysisType="thermalSteady",Geometry=geom3D);
Generate a mesh.
fem = generateMesh(fem,Hmax=H/4);
Account for surface-to-surface radiation in the enclosure formed by the plates by using the
fem = setupRadiation(fem,EnclosureFaces=[5 6]); fem.ThermalRadiation
ans = surfaceToSurfaceSettings with properties: ViewFactors: [204×204 double] Enclosures: dictionary (string ⟼ enclosureDefinition) with 1 entry ParticipatingEnclosures: "Enclosure_1"
If you do not specify enclosure names,
setupRadiation uses the default names, such as
"Enclosure_1". The function also sets the enclosure perfectness to
true, which means that the solver ignores ambient radiation. To change these settings, use the
PerfectEnclosure name-value arguments.
fem = setupRadiation(fem,EnclosureFaces=[5 6], ... EnclosureNames="two_plates", ... PerfectEnclosure=false); fem.ThermalRadiation
ans = surfaceToSurfaceSettings with properties: ViewFactors: [204×204 double] Enclosures: dictionary (string ⟼ enclosureDefinition) with 1 entry ParticipatingEnclosures: "two_plates"
Specify ambient temperature and emissivity for the enclosure formed by the plates.
fem.FaceLoad([5 6]) = faceLoad(AmbientTemperature=0,Emissivity=0.5);
Introduced in R2023b