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doc:user:elements:boundaries:flux

Heat Flux Material

This Documentation refers to Metafor version >= 3593. for more informations on changes see MR !167 for technical informations).

for a Metafor version < 3593, please refers to this page.

Heat Flux Materials are sources of heat that can be applied on boundary of a mesh (Tm(2)boundary2D(3D)Element) or on the mesh (Tm(2)boundary2D(3D)Element) according to the physic (or its model) of the heat source.

Excepted to the UniformHeatFluxMaterial, the flux is linked to a spatial distribution functions related to a set of local coordinates {$x'$, $y'$, $z'$}, which are handled by the X, Y and Z Axis defined in the Material. The local Axis are Line Objects that are defined in the CurveSet and referred in the material by their number.

Coordonnées locales du la source de chaleur

The distribution is following the movement of the Axis (translation/rotation), which is particularly useful for some applications (e.g. additive manufacturing).

Material

Therefore, the first step consist in defining an MaterialProperties, as

mat = materset.define(no, matType )
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 characterises 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)

UniformHeatFluxMaterial

The heat flux is directly given by its value given in the Material Parameters $flux = Q$ with :

  • $Q$ : Heat Flux (boundary : W/m² - Source : W/m³).

As the flux can depend on time, solid temperature, but also current position of the integration point, a distribution can be implemented through dependency function.

Parameters

Name Description Dependency
HEATFLUX_VALUE Value of the heatFlux TM / TO / TX / TY / TZ

RectangularHeatFluxMaterial

The heat flux is given by its value given in the Material Parameters $flux = Q / vol$ if inside a rectangular box (2D or 3D) and $flux = 0$ outside the box.

with :

  • $Q$ : Heat Flux (boundary : W/m² - Source : W/m³).
  • $vol$ : Volume of the box : $vol = c 2a 2b$

As the flux can depend on time, solid temperature, but also current position of the integration point, a distribution can be implemented through dependency function.

Parameters

Name Description Dependency
HEATFLUX_VALUE Value of the heatFlux TM / TO / TX / TY / TZ
HEATFLUX_A dimension of the box in local X' direction -
HEATFLUX_B dimension of the box in local Y' direction -
HEATFLUX_C dimension of the box in local Z' direction (only for Source Elements. In Boundary elements, c = 1.0)
Be Carefull , there are No test if you define C in Boundary element
-
HEATFLUX_NUM_AX_X number of the Line defining the local X axis -
HEATFLUX_NUM_AX_Z number of the Line defining the local Z axis (optional) -
HEATFLUX_RESCALE option to enforce the rescaling of the heatFlux -

EllipsoidHeatFluxMaterial

The heat flux is given by an ellipsoidal distribution :

Add Drawing

$flux = Q \frac{6 \sqrt{3}}{a b c \pi sqrt{\pi}} exp^{(-xpart-ypart-zpart)}$

with :

  • $Q$ : Heat Flux (boundary : W/m² - Source : W/m³).
  • $a$ - $b$ - $c$ : Half diameter of the ellipsoid (related to local axis)
  • $xpart = 3(\frac{x'}{a})^2$ : distribution parameter in first ellipsoid direction
  • $ypart = 3(\frac{y'}{b})^2$ : distribution parameter in second ellipsoid direction
  • $zpart = 3(\frac{z'}{c})^2$ : distribution parameter in third ellipsoid direction

As the flux can depend on time, solid temperature, but also current position of the integration point, a distribution can be implemented through dependency function.

Parameters

Name Description Dependency
HEATFLUX_VALUE Value of the heatFlux TM / TO / TX / TY / TZ
HEATFLUX_A Ellipsoid Half dimension in the local X' direction TM / TX / TY / TZ
HEATFLUX_B Ellipsoid Half dimension in the local Y' direction TM / TX / TY / TZ
HEATFLUX_C Ellipsoid Half dimension in the local Z' direction (only for Source Elements = 2 in boundary element)
Be Carefull , there are No test if you define C in Boundary element
TM / TX / TY / TZ
HEATFLUX_NUM_AX_X number of the Line defining the local X axis -
HEATFLUX_NUM_AX_Z number of the Line defining the local Z axis (optional) -
HEATFLUX_RESCALE option to enforce the rescaling of the heatFlux -

DoubleEllipsoidHeatFluxMaterial

The heat flux is given by an ellipsoidal distribution wit upstream and downstream different size coefficient (inclined heat source according to first local axis)

Add Drawing

upstream ($x' >= 0$) :

  • $flux = Q \frac{2a}{a+ar} \frac{6 \sqrt{3}}{a b c \pi sqrt{\pi}} exp^{(-xpart-ypart-zpart)}$

DownStream ($x' < 0$) :

  • $flux = Q \frac{2ar}{a+ar} \frac{6 \sqrt{3}}{ar b c \pi sqrt{\pi}} exp^{(-xpartR-ypart-zpart)}$

with :

  • $Q$ : Heat Flux (boundary : W/m² - Source : W/m³).
  • $a$ - $b$ - $c$ : Half diameter of the ellipsoid (related to local axis)
  • $xpart = 3(\frac{x'}{a})^2$ : distribution parameter in first ellipsoid direction upstream
  • $xpartR = 3(\frac{x'}{ar})^2$ : distribution parameter in first ellipsoid direction downstream
  • $ypart = 3(\frac{y'}{b})^2$ : distribution parameter in second ellipsoid direction
  • $zpart = 3(\frac{z'}{c})^2$ : distribution parameter in third ellipsoid direction

As the flux can depend on time, solid temperature, but also current position of the integration point, a distribution can be implemented through dependency function.

Parameters

Name Description Dependency
HEATFLUX_VALUE Value of the heatFlux TM / TO / TX / TY / TZ
HEATFLUX_A Ellipsoid Half dimension in the local X' direction UPSTREAM TM / TX / TY / TZ
HEATFLUX_AR Ellipsoid Half dimension in the local X' direction DOWNSTREAM TM / TX / TY / TZ
HEATFLUX_B Ellipsoid Half dimension in the local Y' direction TM / TX / TY / TZ
HEATFLUX_C Ellipsoid Half dimension in the local Z' direction (only for Source Elements = 2 in boundary element)
Be Carefull , there are No test if you define C in Boundary element
TM / TX / TY / TZ
HEATFLUX_NUM_AX_X number of the Line defining the local X axis -
HEATFLUX_NUM_AX_Z number of the Line defining the local Z axis (optional) -
HEATFLUX_RESCALE option to enforce the rescaling of the heatFlux -
doc/user/elements/boundaries/flux.txt · Last modified: by papeleux

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