Since flux interactions are boundary conditions interactions (LoadingInteraction), no materials must be associated to the element.

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

prp = ElementProperties(typeEl)
prp.put(param1, value1)
prp.depend(param1, fct1, Lock1)) #optional
...

where

Thermal heat flux element in 2/3D, first or second order (thermal field of second order), that can be created on “boundary” geometries (i.e. curves in 2D and sides in 3D).

There are currently 4 different heat flux distributions types that are implemented for this element. These can be selected by using the HEATEL_TYPE parameter when defining the element properties.

Heat flux at each Gauss point is equal to HEATEL_VALUE [W/m$^2$].

prp.put(HEATEL_TYPE, HEATEL_CONSTANT)

Heat flux at each Gauss point is equal to a uniform distribution of the total heat $Q_{src}$ within a rectangular surface centered on the local heat flux coordinates $$q = \frac{Q_{src}}{4a b}~~~\text{if } x'\in [-a,~a],~~ y'\in [-b,~b],$$ where $a$ and $b$ are the half lengths of the rectangle in the $x'$ and $y'$ local coordinate directions respectively.

prp.put(HEATEL_TYPE, HEATEL_RECTANGULAR)

Heat flux at each Gauss point is equal to an ellipsoid Gaussian distribution function of the total heat $Q_{src}$ centered on the local heat flux coordinates [Goldak et. al. 1986] $$q = \frac{Q_{src} 6\sqrt{3}}{ab \pi^\frac{3}{2}}~ e^{-3\left(\frac{x'}{a}\right)^2}~ e^{-3\left(\frac{y'}{b}\right)^2}$$ where $a$ and $b$ are the semi-axes lengths of the ellipsoid in the $x'$ and $y'$ directions respectively.

prp.put(HEATEL_TYPE, HEATEL_ELLIPSOID)

Modification of the ellipsoid Gaussian distribution function to account for a different distribution at the front ($x'>=0$) and at the rear ($x'<0$) of the heat flux [Goldak et. al. 1986] $$q_f = f \frac{Q_{src} 6\sqrt{3}}{ab \pi^\frac{3}{2}}~ e^{-3\left(\frac{x'}{a}\right)^2}~ e^{-3\left(\frac{y'}{b}\right)^2}, ~~~~~~~~x'>=0$$ $$q_r = (1-f) \frac{Q_{src} 6\sqrt{3}}{a_rb \pi^\frac{3}{2}}~ e^{-3\left(\frac{x'}{a_r}\right)^2}~ e^{-3\left(\frac{y'}{b}\right)^2}, x'<0$$ where $a$ and $a_r$ are the front and rear semi-axes lengths in the $x'$ directions, $b$ is the semi-axis length in the $y'$ direction, and $f=\frac{ba}{a+a_r}$ is the balancing factor.

prp.put(HEATEL_TYPE, HEATEL_DOUBLE_ELLIPSOID)

Thermal heat source element in 2/3D, first or second order (thermal field of second order), that can be created on “volume” geometries (i.e. sides in 2D and volumes in 3D).

There are currently 4 different types of heat source distributions that are implemented for this element. These can be selected by using the HEATEL_TYPE parameter when defining the element properties.

Heat source at each Gauss point is equal to HEATEL_VALUE [W/m$^3$].

prp.put(HEATEL_TYPE, HEATEL_CONSTANT)

Heat source at each Gauss point is equal to a uniform distribution of the total heat $Q_{src}$ within a box volume centered on the local heat flux coordinates $$q = \frac{Q_{src}}{8a b c}~~~\text{if } x'\in [-a,~a],~~ y'\in [-b,~b],~~ z'\in [-c,~c],$$ where $a$, $b$ and $c$ are the half lengths of the rectangle in the $x'$, $y'$ and $z'$ local coordinate directions respectively.

prp.put(HEATEL_TYPE, HEATEL_RECTANGULAR)

Heat source at each Gauss point is equal to an ellipsoid Gaussian distribution function of the total heat $Q_{src}$ centered on the local heat flux coordinates [Goldak et. al. 1986] $$q = \frac{Q_{src} 12\sqrt{3}}{abc \pi^\frac{3}{2}}~ e^{-3\left(\frac{x'}{a}\right)^2}~ e^{-3\left(\frac{y'}{b}\right)^2}~ e^{-3\left(\frac{z'}{c}\right)^2}$$ where $a$, $b$ and $c$ are the semi-axes lengths of the ellipsoid in the $x'$, $y'$ and $z'$ directions respectively.

prp.put(HEATEL_TYPE, HEATEL_ELLIPSOID)

Modification of the ellipsoid Gaussian distribution function to account for a different distribution at the front ($x'>=0$) and at the rear ($x'<0$) of the heat flux [Goldak et. al. 1986] $$q_f = f \frac{Q_{src} 12\sqrt{3}}{ab \pi^\frac{3}{2}}~ e^{-3\left(\frac{x'}{a}\right)^2}~ e^{-3\left(\frac{y'}{b}\right)^2}~ e^{-3\left(\frac{z'}{c}\right)^2}, ~~~~~~~~x'>=0$$ $$q_r = (1-f) \frac{Q_{src} 12\sqrt{3}}{a_rb \pi^\frac{3}{2}}~ e^{-3\left(\frac{x'}{a_r}\right)^2}~ e^{-3\left(\frac{y'}{b}\right)^2}~ e^{-3\left(\frac{z'}{c}\right)^2}, x'<0$$ where $a$ and $a_r$ are the front and rear semi-axes lengths in the $x'$ directions, $b$ and $c$ are the semi-axes lengths in the $y'$ and $z'$ direction, and $f=\frac{ba}{a+a_r}$ is the balancing factor.

prp.put(HEATEL_TYPE, HEATEL_DOUBLE_ELLIPSOID)

Thermal convection heat flux element in 2/3D, first or second order (thermal field of second order), that can be created on “boundary” geometries (i.e. curves in 2D and sides in 3D).

The interaction is defined as:

load = HeatInteraction(no)
load.push(gObject1)
load.push(gObject2)
...
load.setAxes(Ox, Oz)
load.useRescale(bool)
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
Ox, Oz	Curve entities that define the local coordinates $x'$ and $z'$ for the heat distribution function (not necessary for HEATEL_CONSTANT)
useRescale(bool)	Rescaling of the heat flux = False (default): do nothing = True: allows the rescaling of all heat source at each beginning of time-step to obtain the exact value of total applied HEATEL_VALUE not for HEATEL_CONSTANT and Tm[2]ConvectionHeatFlux[2|3]DElement