1. Reference problem#
1.1. Geometry#
1.2. Material properties#
The material has the following thermal characteristics:
Thermal conductivity: \({k}_{s}=6\mathrm{kJ}/h/m/°K\)
enthalpy volume change: \(\Delta H=2.4105\mathrm{kJ}/{m}^{3}\),
and the following characteristics relating to moisturizing behavior:
Heat by hydration level: \({Q}_{0}=1.4904105\mathrm{kJ}/{m}^{3}\)
Arrhenius constant: \(\mathrm{Ar}=4000/°K\).
Note:
The Arrhenius constant is always expressed in degrees Kelvin. Temperatures are expressed in \(°C\).
Affinity as a function of hydration:
Degree of hydration \(h\) |
Affinity \(A(h)(1/h)\) |
0 |
6510 |
0.008 |
6360 |
0.016 |
2485 |
0.019 |
2460 |
0.038 |
9520 |
0.047 |
21800 |
0.08 |
37600 |
0.138 |
51600 |
0.232 |
51400 |
0.351 |
28200 |
0.44 |
16100 |
0.5 |
11700 |
0.63 |
5570 |
0.73 |
4240 |
0.81 |
1780 |
0.88 |
302 |
0.97 |
50 |
1.00 |
0 |
1.3. Boundary conditions and loads#
A zero heat flux is imposed on all faces of the solid. Charging is only initiated by a heat source dependent on hydration \(\Delta Q={Q}_{0}\Delta h\).
1.4. Initial conditions#
The initial temperature is \(20.9°C\)
1.5. Discretization in time#
The explicit integration of hydration requires fine temporal discretization until the end of the hydration phenomenon:
From \(t=0\) to \(t=\mathrm{20h}\), \(\Delta t=\mathrm{7,5}\mathrm{min}\) is 160 steps.
From \(t=\mathrm{20h}\) to \(t=\mathrm{60h}\), \(\Delta t=1h\) is 40 steps.