# TIMBC

**TIMBC**            permits the users to specify time-dependent Dirichlet boundary conditions. All values in this data block are read in free format (be careful, this record does not compatible with TOUGH3 input). The inputs either is through a file named "timbc.dat" or through the data section following this keyword. If "timvsp.dat" exists in the working folder, data are directly read from the file and the inputs in the TIMBC section will be neglected.&#x20;

Record **TIMBC.1**

&#x20;                       NTPTAB, T3Comp

*NTPTAB*          number of elements with time-dependent boundary conditions.

T3Comp          This parameter is optional. If  T3Comp="T3", the input format will be compatible with TOUGH3 input ( see TOUGH3 user manual for details), and the following input formatting will not be applied.&#x20;

Record **TIMBC.2**   &#x20;

&#x20;                       BEleName, NBCP, NBCPV&#x20;

*BEleBame*        name of boundary element

*NBCP*               number of times.

*NBCPV*            numbering of primary variable that is time dependent, e.g., 1 for pressure. It can be different for different EOS module and different phase state condition.&#x20;

Record **TIMBC.3**

&#x20;                       TIMBCV, PGBCEL

*TIMBCV*          the time when primary variable *NBCPV* at boundary element *BCELM* is specified.

*PGBCEL*          value of primary variable *NBCPV* at boundary element *BCELM* at time *TIMBCV.*  A special case will be evoked if *PGBCEL<0.0.* Once *PGBCEL<0.0,* the current element will return to regular element with a volume of abs(*PGBCEL),* and will not be treated as first type boundary since time *TIMBCV*.  It is also allowed this element changes back to first type boundary again if  *PGBCEL* become larger than 0.0 at later time.

The default phase state condition will be the current condition of the element. User may specify a new phase condition through a special case for NBCPV =2, by PGBCEL=:

&#x20;                       0-1.0:       default phase condition.

&#x20;                       10.0+sg:  two-phase condition.

&#x20;                       20.0+xg:  single gas phase condition.

&#x20;                      30.0+xg:  single aqueous phase condition.

Repeat TIMBC.3 for *NBCP* times.&#x20;

Repeat records TIMBC.2, TIMBC.3 for all *NPTTAB* elements.

**Used in**: All EOS modules

**Example**

*TIMBC*

*2                                            // time-dependent first-type boundary at 2 elements*&#x20;

*ELEM1, 3, 1                         // 1st element name, change at 3 times, time-dependent: 1st PV*&#x20;

*1000.0, 1.0e7                     //time1, the value of 1st primary variable at time1*

*2000.0, 2.0e7                    //time2, the value of 1st primary variable at time2*

*4000.0, 2.5e7                    //time3, the value of 1st primary variable at time3*

*ELEM2, 2, 4                       // 2nd element name, change at 2 times, time-dependent: 4th PV*&#x20;

*2000.0, 40.0                     // time1, the value of 4th primary variable at time1*

*4000.0, 45.0                     // time2, the value of 4th primary variable at time2*
