FEM4EllipticPDE/examples/borehole/boreholeMagnetGrid.geo

/**
 *  Trevor P. Irons, XRI Geophysics, LLC
 *  Test of Coloumbic Magnetic Potential
 */

lc = 1e-2;   // Target element size
R =  .05;    // Magnet Radius
D0 = 9.5;    // Top of mesh
D1 = 11.5;   // Bottom of mesh

// Total Solution Space
X0 = -2.;
X1 =  2.;
Y0 = -2.;
Y1 =  2.;
//Z0 =  9.5;
//Z1 = 11.5;

////////////////////////////////////
// North Pole

Function Ring
    X *= 1.2;
    // North Pole
    p0 = newp; Point(p0) = {   0,   0, D0, lc};
    p1 = newp; Point(p1) = { X*R,   0, D0, lc};
    p2 = newp; Point(p2) = {   0, X*R, D0, lc};
    p3 = newp; Point(p3) = {-X*R,   0, D0, lc};

    c1 = newc; Circle(c1) = {p1, p0, p3};
    l1 = newl; Line(l1) = {p3,p1};
    l2 = newl; Line Loop(l2) = {c1, l1};
    s1 = news; Plane Surface(s1) = {l2};
    Extrude {0, 0, D1-D0} { Surface{s1};  }

    // South Pole
    p4 = newp; Point(p4)  = {   0,  -0.0001, D0, lc}; //  8
    p5 = newp; Point(p5)  = { X*R,  -0.0001, D0, lc}; //  9
    p6 = newp; Point(p6)  = {   0,  -X*R,    D0, lc}; // 10
    p7 = newp; Point(p7)  = {-X*R,  -0.0001, D0, lc}; // 11

    c2 = newc; Circle(c2) = {p7, p4, p5};
    l3 = newl; Line(l3) = {p5,p7};
    l4 = newl; Line Loop(l4) = {c2, l3};
    s2 = news; Plane Surface(s2) = {l4};
    Extrude {0, 0, D1-D0} { Surface{s2};  }

    //Compound Volume(4) = {vol2[1], vol3[1]};

//Circle(12) = {11, 8, 9};
//Line(13) = {9, 11};
//Line Loop(14) = {12, 13};
//Plane Surface(15) = {14};

Return

X = 1.;
For r In {1:10}
  Call Ring;
EndFor

/*

Point(0) = { 0, 0, D0, lc};
Point(1) = { R, 0, D0, lc};
Point(2) = { 0, R, D0, lc};
Point(3) = {-R, 0, D0, lc};

// Connect up the points
Circle(4) = {1, 0, 3};
Line(5) = {3,1};
Line Loop(6) = {4,5};
Plane Surface(7) = {6};

////////////////////////////////////
// South Pole

Point(8)  = { 0,  -0.0001, D0, lc};
Point(9)  = { R,  -0.0001, D0, lc};
Point(10) = { 0, -R, D0, lc};
Point(11) = {-R,  -0.0001, D0, lc};

// Connect up the points
Circle(12) = {11, 8, 9};
Line(13) = {9, 11};
Line Loop(14) = {12, 13};
Plane Surface(15) = {14};

//////////////////////////////////////
// Extrude magnet
Extrude {0, 0, D1-D0} { Surface{7};  }
Extrude {0, 0, D1-D0} { Surface{15}; }

/////////////////////////////////////
// Large Bounding box
Point(116)  = {X0, Y0, Z0};
Point(117)  = {X1, Y0, Z0};
Point(118)  = {X1, Y1, Z0};
Point(119)  = {X0, Y1, Z0};
Line(120) = {116,117};
Line(121) = {117,118};
Line(122) = {118,119};
Line(123) = {119,116};
Line Loop(124) = {120, 121, 122, 123};
Plane Surface(125) = {124};
Extrude {0, 0, Z1-Z0} { Surface{125}; }

//////////////////////////////////////
// Rings of sensitivity calculation
//Circle(222) = {2.*1, 0, 2.*2};


//////////////////////////////////////
// Volumes

Physical Volume("plus") = {2};
Physical Volume("minus") = {1};
Physical Volume("background") = {3};
Coherence;
*/