CONNE

Keywork CONNE is used for define the connections of model mesh. It must be placed after the keyword ELEME.

CONNE introduces information for the connections (interfaces) between elements.

Record CONNE.1

Free format for 8 parameters

ELNE1, ELNE2, ISOT, D1, D2, AREAX, BETAX, SIGX

Or Format (A3, I2, A3, I2, 4I5, 5E10.4) (for 5 five-character element name only).

EL1, NE1, EL2, NE2, NSEQ, NAD1, NAD2, ISOT, D1, D2, AREAX, BETAX, SIGX

ELNE1 first element name.

ELNE2 second element name.

EL1, NE1 code name of the first element (for formatted input only).

EL2, NE2 code name of the second element (for formatted input only).

NSEQ number of additional connections in the sequence (used for formatted input only).

NAD1 increment of the code number of the first element between two successive connections sequence (used for formatted input only).

NAD2 increment of the code number of the second element between two successive connections (used for formatted input only).

ISOT set equal to 1, 2, or 3; specifies absolute permeability to be PER(ISOT) for the materials in elements (ELNE1) and (ELNE2), where PER is read in block ROCKS. This allows assignment of different permeabilities, e.g., in the horizontal and vertical direction. ISOT can be in negative or a number large than 3 for some specific purposes such as in wellbore simulation (see Section 7/wellbore flow/subsection 2) and active fracture model.

D1 distance (m) from first element to interface.

D2 distance (m) from second element to interface.

AREAX interface area (m2).

BETAX cosine of the angle between the gravitational acceleration vector and the line between the two elements. GF × BETAX > 0 (<0) corresponds to first element being above (below) the second element.

SIGX “radiant emittance” factor for radiative heat transfer, which for a perfectly “black” body is equal to 1. The rate of radiative heat transfer between the two grid blocks is

$G_{rad}=SIGX*\sigma_0*AREAX*(T_2^4-T_1^4)$ (8-1)

where $\sigma _0=5.6687e^{-8}J/m^2K^4s$ is the Stefan-Boltzmann constant, and $T_1$and $T_2$ are the absolute temperatures of the two grid blocks. SIGX may be entered as a negative number, in which case the absolute value will be used, and heat conduction at the connection will be suppressed. SIGX = 0 will result in no radiative heat transfer.

Repeat record CONNE.1 for the number of connections desired.

Record CONNE.2 A blank record closes the CONNE data block. Alternatively, connection information may terminate on a record with ‘+++’ typed in the first three columns, followed by element cross-referencing information. This is the termination used when generating a MESH file with TOUGH4.

Used in: All EOS modules

Example:

CONNE // this is for input in the main input file

A1001, A1002, 3*0, 1, 0.150000E-05, 0.153200E+00, 0.188500E+03, 2*0.0

In the free format MESH file, TOUGH4 does not allow including NSEQ, NAD1, and NAD2 in input line:

CONNE

A1001, A1002, 1, 0.150000E-05, 0.153200E+00, 0.188500E+03, 2*0.0