4. B modeling#
Fluid behavior: THMC = LIQU_GAZ_ATMavec a constant saturation \(S=1\)
4.1. Characteristics of B modeling#
Plane modeling: D_ PLAN_HM
4.2. Tested sizes and results#
Discretization in time: Several time steps (16) to study the evolution of pressure during the transition phase until it stabilizes. The time pattern is implicit \((\vartheta =1)\).
List of calculation times in seconds:
\(\mathrm{1,}\mathrm{5,}\mathrm{10,}\mathrm{50,}\mathrm{100,}\mathrm{500,}{10}^{3},{5.10}^{3},{10}^{4},5.{10}^{4},{10}^{5},5.{10}^{5},{10}^{6},5.{10}^{6},{10}^{7},{10}^{10}\)
The nodal fluid pressure unknowns evaluated in Code_Aster are variations from the initial reference pressures defined under the keyword THM_INIT, which is why this table shows pressure variations in our comparison between the Code_Aster calculation and the reference solution.
Node/point |
Order Number |
Press |
Reference |
|
\((\mathrm{Pa})\) « |
Tolerance \((\text{\%})\) |
|||
\(\mathrm{N1}/A\) |
1 (t=1 s) |
\(\mathrm{PRE1}\) |
|
1.0 |
2 (t=5s) |
\(\mathrm{PRE1}\) |
|
1.0 |
|
3 (t=10 s) |
\(\mathrm{PRE1}\) |
|
1.0 |
|
4 (t=50s) |
\(\mathrm{PRE1}\) |
|
1.0 |
|
8 (t=5.103s) |
\(\mathrm{PRE1}\) |
|
1.0 |
|
16 (t=1010s) |
\(\mathrm{PRE1}\) |
|
1.0 |
|
\(\mathrm{N3}/C\) |
1 (t=1 s) |
\(\mathrm{PRE1}\) |
|
1.0 |
2 (t=5s) |
\(\mathrm{PRE1}\) |
1,99.10-1 |
1.0 |
|
3 (t=10 s) |
\(\mathrm{PRE1}\) |
3,98.10-1 |
2.0 |
|
4 (t=50 s) |
\(\mathrm{PRE1}\) |
1.99 |
2.0 |
|
8 (t=5.103s) |
\(\mathrm{PRE1}\) |
1,95.10+2 |
1.0 |
|
16 (t=1010s) |
\(\mathrm{PRE1}\) |
5.10+3 |
1.0 |
4.3. notes#
Note that the pressures calculated for the two previous behaviors (THMC = LIQU_SATU (model \(A\)) and THMC = LIQU_GAZ_ATM (model \(B\))) are equal in absolute values. The difference in signs is due to the fact that:
the pressure \(\mathrm{PRE1}\) evaluated in the code is the water pressure for the behavior THMC = LIQU_SATU,
\(\mathrm{PRE1}\) is equal to the capillary pressure for the behavior THMC = LIQU_GAZ. Capillary pressure is equal to the difference between gas pressure and liquid pressure. In the particular case where the dry air pressure is atmospheric pressure (THMC = LIQU_GAZ_ATM), the capillary pressure has the opposite value of the liquid pressure.