20.2.4 VERTEX_T_DEPENDENT and CELL_T_DEPENDENT

For both equation types VERTEX_T_DEPENDENT and CELL_T_DEPENDENT the property is calculated using linear interpolation between the data sets. After the equation type keyword the number of data sets must be specified. Each of the data sets consists of a temperature value followed by a property value. There must be at least two data sets. The data sets should be ordered such that the temperature increases from one data set to the next. An error will be raised if during the simulation the property has to be calculated for a temperature outside the range of temperatures specified by the data sets. For material number 1 the entries for a CELL_T_DEPENDENT property can be either

MATERIAL 1 CALL_T_DEPENDENT  4  -100.0 1.0 100.0 1.0 300.0 1.4 1.0E+07 1.4

or

MATERIAL 1 CALL_T_DEPENDENT  4  
                       -100.0     1.0 
                        100.0     1.0 
                        300.0     1.4 
                        1.0E+07   1.4

The number of data sets must be on the same line as the material number but the data sets can be spread over any number of lines, with any number of values on any of the lines. The value of the property is calculated using

$$p^i + \frac{p^{i+1}-p^i}{T^{i+1}-T^i}(T-T^i)$$

where pⁱ is the property value in data set i, Tⁱ is the temperature value in the same data set and T is the temperature at which the property value is to be calculated. The data sets, chosen to evaluate the property are those for which

$$T^i \; < \; T \; \leq \; T^{i+1}$$