We demonstrate here how to use msbGrid to create a 3-blocks quadrilateral hybrid (structured-unstructured) grid. This same grid is used in the Two phases fluid flow in fractured porous media section.

Input Parameters

The input parameters for the test example test1.cc are

Parameter	description
xMin	bounding box minimum x value (yMin = xMin)
xMax	bounding box maximum x value (yMax = xMax)
bnCx	block number in the x direction
bnCy	block number in the y direction
dr	blocks elements (square in 2D) side length
rafC	rafinement coefficient in the inter blocks area
bCId	randomly generated block centers identifier
bAId	randomly generated block angles identifier
bCPC	block centers perturbation coefficient, the perturbation magnitude = bCPC * dr
d2bC	distance to the boundary coefficien, the distance to the boundary = d2bC * dr
intbC	inter-blocks coefficient, the inter-blocks distance = intbC * dr

Runing test1: $ cd tests/test1/

in the case of using command line options
$ ./test1 --outputPath="./output/" --outputDirName="ctest_1" --xMin="0" --xMax="1" --bnCx="1" --bnCy="3" --dr="0.02" --rafC="1" --bCId="0" --bAId="0" --bCPC="0" --d2bC="1" --intbC="1"

in the case of using the default input parameter file ${executableName}.input (= test1.input)
$ ./test1

where
#########################################################################################################

## File: test1.input (default input parameter file for test1.cc)

## Everything behind a '#' is a comment.

## Type "./test1 --help" for more information.

## Type "./test1" to run the program if test1.input exist

## or specify another parameter file "./test1 --parameterFile="path/to/parameterfile.input"

## Remark:

## If BCDistType="predefined" the following parameters are not considered: xMin, xMax, BnCx and BnCy

## xMin and xMax are in fact defined by the method predefinedDist() of the class Test1InitialDistribution

#########################################################################################################

OutputPath="./output/" ## default value OutputPath="../../output/"

OutputDirName="ctest_1" ## default value OutputDirName="outputDirectory"

XMin="0" ## default value XMin="0"

XMax="1" ## default value XMax="1"

BnCx="1" ## default value BnCx="1"

BnCy="3" ## default value BnCy="1"

Dr="0.02" ## default value Dr="0.1"

RafC="1" ## default value RafC="1"

BCDistType="random" ## default value BCDistType="random"

BADistType="random" ## default value BADistType="random"

BCId="0" ## default value BCId="0"

BAId="0" ## default value BAId="0"

BCPC="0" ## default value BCPC="0"

D2bC="1" ## default value D2bC="1"

IntbC="1" ## default value IntbC="1"

Note: in input parameter files, parameters names must begin with big letter, otherwise they are not recongnized (unlike in the command line options where they can be either in big or small letters).

in the case of using an input parameter file other than the default
$ ./test1 --parameterFile="path/to/otherParameterfile"

Attention: command line options have priority over the options from the input parameter file

Making the .msh file: $ gmsh -2 msbGrid_ctest_1.geo

msbGrid_ctest_1 (2644 Quadrangles, 2745 Nodes)

Outlines of the resulting .geo files

Note: the msbGrid_${outputDirName}.geo (= msbGrid_ctest_1.geo) is the (principal) file that include all the other .geo files created by test1.

/// file: msbGrid_ctest_1.geo

Include "blPtExtBound_.geo";
Include "vBlPtI_.geo";
Include "vEdExtBound_.geo";
Include "vBlEd_.geo";
Include "vBlQd_.geo";
Include "blockBoundary_.geo";

Mesh.RecombineAll = 1;

/// file: blPtExtBound_.geo

//////////////////////////////
// external boundary points //
//////////////////////////////
Point(1) = {0.000000, 0.000000, 0.000000, 0.020000};
Point(2) = {0.000000, 1.000000, 0.000000, 0.020000};
Point(3) = {1.000000, 1.000000, 0.000000, 0.020000};
Point(4) = {1.000000, 0.000000, 0.000000, 0.020000};

/// file: vBlPtI_.geo

/// Block 1
Point(5) = {0.487513, 0.160027, 0.000000, 1.000000};
Point(6) = {0.506639, 0.154180, 0.000000, 1.000000};
...

/// Block 2
Point(767) = {0.487631, 0.506856, 0.000000, 1.000000};
Point(768) = {0.493144, 0.487631, 0.000000, 1.000000};
...

/// Block 3
Point(1542) = {0.486550, 0.837703, 0.000000, 1.000000};
Point(1543) = {0.495630, 0.819883, 0.000000, 1.000000};
...
Point(2256) = {0.020511, 0.959389, 0.000000, 1.000000};

/// file: vEdExtBound_.geo

//////////////////////////////
// external boundary lines  //
//////////////////////////////
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};

/// file: vBlEd_.geo

/// Block 1
Line(5) = {5, 6};
Line(6) = {5, 7};
...

/// Block 2
Line(1450) = {767, 768};
Line(1451) = {767, 769};
...

/// Block 3
Line(2921) = {1542, 1543};
Line(2922) = {1542, 1544};
...
Line(4269) = {2254, 2255};

/// file: vBlQd_.geo

/// Block 1
Line Loop(1) = {+5, +7, -8, -6};
Plane Surface(1) = {1};
Transfinite Line{5, 7, 8, 6} = 2 Using Progression 1;
Transfinite Surface{1} = {5, 6, 8, 7};
...

/// Block 2
Line Loop(685) = {+1450, +1452, -1453, -1451};
Plane Surface(685) = {685};
Transfinite Line{1450, 1452, 1453, 1451} = 2 Using Progression 1;
Transfinite Surface{685} = {767, 768, 770, 769};
...

/// Block 3
Line Loop(1382) = {+2921, +2923, -2924, -2922};
Plane Surface(1382) = {1382};
Transfinite Line{2921, 2923, 2924, 2922} = 2 Using Progression 1;
Transfinite Surface{1382} = {1542, 1543, 1545, 1544};
...
Line Loop(2016) = {+4256, +4268, -4269, -4262};
Plane Surface(2016) = {2016};
Transfinite Line{4256, 4268, 4269, 4262} = 2 Using Progression 1;
Transfinite Surface{2016} = {2233, 2234, 2255, 2254};

Physical Surface(2017) = {1:2016};
Color White {Surface {1:2016};}

/// file: blockBoundary_.geo

///////////////////////
// Block line Loops  //
///////////////////////

/// Boundary of Block 1, Line Loop 2017
Line Loop(2017) = {+237, -313, +314, +312, -310, +308, -481,..., -318, +319, +238};

/// Boundary of Block 2, Line Loop 2018
Line Loop(2018) = {+1706, -1792, -1794, -1798, -1802, -1894, -1895,..., -1881, +1782, -1787};

/// Boundary of Block 3, Line Loop 2019
Line Loop(2019) = {+3169, -3255, -3256, +3177, -3261, -3263, -3337,..., +3243, -3246, +3247};

//////////////////////////////////
// external boundary line Loop  //
//////////////////////////////////

/// Line Loop 2020
Line Loop(2020) = {+1, +4, +3, +2};

/////////////////////////////////
// inter-blocks plane surface  //
/////////////////////////////////

/// Plan Surface 2018
Plane Surface(2018) = {2017,2018,2019,2020};
Physical Surface(2018) = {2018};

Color Red {Surface {2018};}