Learning Forum

[moi amibe]

Hi, how to define enthalpie of reaction using transient thermal ?

[Chandra Sekaran]

To input enthalpy material property in an APDL script, you can use the 'MPDATA' command. This command allows you to define material properties that are associated with a temperature table, which must be defined first using the 'MPTEMP' command. Here's an example script that demonstrates how to input enthalpy:

! Define temperature points
MPTEMP,1,0,100,200,300,400,500
! Define enthalpy values at the specified temperatures
MPDATA,ENTH,1,,900,1800,2700,3600,4500

In this example, 'MPTEMP' defines the temperature points, and 'MPDATA' assigns the enthalpy values at those temperatures for material reference number 1. The 'ENTH' label is used to specify that the data being defined is enthalpy. The values after 'ENTH' represent the enthalpy at each temperature point, in units of J/m^3 as suggested for a transient thermal analysis.

Remember to replace the enthalpy values with those appropriate for your specific material and analysis.

[moi amibe]

Thanks, is it possible to go beyond T6, for example T7, T8 ? in MPTEMP

[Chandra Sekaran]

The format is MPTEMP, SLOC, T1, T2, T3, T4, T5, T6 where SLOC is the starting location. Similar field exists in MPDATA also .

So if you have more than 6 temperatures you can do the following:

mptemp,1,100,200,300,400,500,600

mptemp,7,700,800,900

mpdata,enth,1,1,900,1800,2700,3600,4500

mpdata,enth,1,7,6000,7500,9000

[moi amibe]

thank you

I work on phase change materials, with transient thermal. how to achieve a phase change (especially fusion) ? please