doc:user:elements:boundaries:radiation
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Table of Contents
Radiation
RadiativeMaterial
The RadiativeMaterial is implemented to take into account the heat exchange between the boundary of a mesh and the surrounding atmosphere (at uniform Temperature) without taking into account any view factor or self exchange between mesh.
the heatFlux (W/m² / mW/mm²) is equal to $flux = \sigma \epsilon (T^4-T_{amb}^4)$
It is design to work with Tm(2)Boundary2D(/3D)Element. By default, the surrounding model has to be defined in Kelvin, but defining the parameter RAY_CELSIUS to True allows using it in a Celsius defined test.
''' mat = materset.define(no, RadiativeMaterial ) mat .put(param1, value1) mat .depend(param1, fct1, Lock1)) #optional ...
where
param1 | name of the property associated to the element (for example RAY_EMISSIVITY |
value1 | value of the corresponding property |
fct1 | function which characterizes the dependency of the property (optional: no fct if no dependency) |
Lock1 | Lock which defines the dependency variable of the property (compulsory if there is a dependency) |
Parameters
| Name | Description | Dependency |
|---|---|---|
STIFFMETHOD | Method used to compute the stiffness matrix\\= STIFF_ANALYTIC : analytic matrix (default)= STIFF_NUMERIC : numerical matrix | - |
BOLTZMANN_CST | Boltzmann Constant (required to set units) = $ 5.67e^{-8} W/m^2K^4 $ = $ 5.67e^{-11} mW/mm^2K^4$ | Set |
RAY_EMISSIVITY | Relative emissivity between two gray bodies (solid / room) $\epsilon = \frac{\epsilon_1 * \epsilon_2}{\epsilon_1 + \epsilon_2 - \epsilon_1 * \epsilon_2}$ | time |
RAY_TEMP_AMB | Room temperature (K) | time |
NPG | Number of integration points (default : tm : 2 / tm2 : 3) | - |
Interaction
The interaction is defined as:
load = LoadingInteraction(no) load.push(gObject1) load.push(gObject2) ... load.addProperty(prp) interactionset.add(load)
where
no | number of the Interaction |
gObject1, gObject2 | mesh geometric entity where the boundary conditions are applied |
prp | Properties of boundary condition elements to generate |
doc/user/elements/boundaries/radiation.1785329917.txt.gz · Last modified: by papeleux