12.1.2 Variable Properties

Next: 12.1.3 Time Dependent Diffusion Up: 12.1 Conductivity and Capacitance Previous: 12.1.1 Constant Properties Contents Index

12.1.2 Variable Properties

The conductivity and capacitance may depend on potential (temperature or concentration), on time, or on both potential and time simultaneously.

Dependency on potential (syntax)

$\begin{figure}\centering \begin{tabbing} \texttt{'MATERI'} \\ [-1.0ex] \rule{14... ...}\,\) {[}\ldots \texttt{\textit{cn}}$_{r}\,${]} {]} \end{tabbing} \end{figure}$

TEMPER: te1 ...ten are the temperatures T_{i=1, n} for which the material properties are specified. This input applies for a heat flow analysis.
CONCEN: co1 ...con are the concentrations C_{i=1, n} for which the material properties are specified. This input applies for a concentration flow analysis.
POTENT: phi1 ...phin are the potentials $\phi_{{i=1,n}}^{}$ for which the material properties are specified. This input applies for potential flow analyses other than heat flow or concentration flow.
CONDIS: k1 ...kn are the conductivities k_{i=1, n} for the corresponding temperatures, concentrations or potentials. If you specified an orthotropic or anisotropic constant conductivity CONDUC, DIANA assumes that k1 ...kn are the values for k_xx and scales the other components proportionally to the values for constant conductivity.
CAPATT: c1 ...cn are the capacitances c_{i=1, n} for the corresponding temperatures, concentrations or potentials.

(file.dat)

'MATERI'
    1 POTENT  -1.0E+3 1.0E+3
      CONDIS   1.0E-2 2.0E-2
      CAPATT   4.0E-2 5.0E-2

This example input specifies linear diagrams for potential dependent conductivity and capacitance for material number 1 as shown in Figure 12.1.

**Figure 12.1:** Potential dependent conductivity and capacitance
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Dependency on time (syntax)

$\begin{figure}\centering \begin{tabbing} \texttt{'MATERI'} \\ [-1.0ex] \rule{14... ...}\,\) {[}\ldots \texttt{\textit{cn}}$_{r}\,${]} {]} \end{tabbing} \end{figure}$

TIME: t1 ...tn are the times t_{i=1, n} for which the material properties are specified.
CONDIS: k1 ...kn are the conductivities k_{i=1, n} for the corresponding times. If you specified an orthotropic or anisotropic constant conductivity CONDUC, DIANA assumes that k1 ...kn are the values for k_xx and scales the other components proportionally to the values for constant conductivity.
CAPATT: c1 ...cn are the capacitances c_{i=1, n} for the corresponding times.

(file.dat)

'MATERI'
    1 TIME    0.     500.0  1000.0
      CONDIS  0.01   0.005  0.0025
      CAPATT  0.04   0.02   0.1

This example input specifies bilinear diagrams for nonlinear conductivity and capacitance for material number 1 as shown in Figure 12.2.

**Figure 12.2:** Time dependent conductivity and capacitance
$\begin{figure}\begin{small}\setlength{\unitlength}{1cm} \begin{picture}(11.0,... ...% }% \centerline{\raise 3.5cm\box\graph} } \end{picture}\end{small} \end{figure}$

Dependency on time and potential (syntax)

$\begin{figure}\centering \begin{tabbing} \texttt{'MATERI'} \\ [-1.0ex] \rule{14... ...,\) {[}\ldots \texttt{\textit{cmtn}}$_{r}\,${]} {]} \end{tabbing} \end{figure}$

TIME: t1 ...tn are the times t_{i=1, n} for which the material properties are specified.
TEMPER: te1 ...tem are the temperatures T_{i=1, m} for which the material properties are specified. This input applies for a heat flow analysis.
CONCEN: co1 ...com are the concentrations C_{i=1, m} for which the material properties are specified. This input applies for a concentration flow analysis.
POTENT: phi1 ...phim are the potentials $\phi_{{i=1,m}}^{}$ for which the material properties are specified. This input applies for potential flow analyses other than heat flow or concentration flow.
CONDIS: k1t1 ...k1tn are the conductivities k_{i=1, n} for the corresponding times and the first temperature, concentration or potential, k2t1 ...k2tn are the conduction coefficients for the same times but for the second temperature, concentration or potential, and so on until the conductivities kmt1 ...kmtn for the last temperature, concentration or potential. If you specified an orthotropic or anisotropic constant conductivity CONDUC, DIANA assumes that k1 ...kn are the values for k_xx and scales the other components proportionally to the values for constant conductivity.
CAPATT: c1t1 ...c1tn are the capacitances c_{i=1, n} for the corresponding times and the first temperature, concentration or potential, c2t1 ...c2tn are the capacitances for the same times but for the second temperature, concentration or potential, and so on until the capacitances cmt1 ...cmtn for the last temperature, concentration or potential.

(file.dat)

'MATERI'
   1 TIME     0.     5.0E2 1.0E3
     POTENT  -1.0E3
              1.0E3
     CONDIS   1.0E-2 5.0E-3 2.5E-3
              2.0E-2 1.0E-2 5.0E-3

This example input specifies two time-conductivity diagrams: the first one for potential $\phi$ = - 1000 and the second one for potential $\phi$ = 1000 as shown in Figure 12.3.

**Figure 12.3:** Time and potential dependent conductivity
$\begin{figure}\begin{small}\setlength{\unitlength}{1cm} \begin{picture}(8.5,5... ...% }% \centerline{\raise 5.9cm\box\graph} } \end{picture}\end{small} \end{figure}$

Next: 12.1.3 Time Dependent Diffusion Up: 12.1 Conductivity and Capacitance Previous: 12.1.1 Constant Properties Contents Index

DIANA-9.3 User's Manual - Material Library
First ed.

Copyright (c) 2008 by TNO DIANA BV.