Meshing in Gmsh
 

Hello,

I am new to gmsh and I recently created a structured mesh for the NACA0012 airfoil (to run in openFoam). However, I seem to have a spot with an abnormality/mixing of meshes near the front of the airfoil.

Here's a photo of the mesh issue:
Attachment 96503


Here is the code for my mesh as well:
Include "airfoil0012d.geo";
//+
y = 4;
x = 10;
n_inlet = 60;
n_vert = 90;
r_vert = 1;
n_af = 50;
n_wake = 100;
r_wake = 1;


//+
Point(135) = {1.005, y, 1, 1.0};
//+
Point(136) = {1.005, -y, 1, 1.0};
//+
Point(137) = {x, -y, 1, 1.0};
//+
Point(138) = {x, y, 1, 1.0};
//+
Point(139) = {x, 0, 1, 1.0};
//+
Point(141) = {0, -y, 1, 1.0};
//+
Point(142) = {0, y, 1, 1.0};
//+
Line(5) = {135, 138};
//+
Line(6) = {138, 139};
//+
Line(7) = {139, 137};
//+
Line(8) = {137, 136};
//+
Line(9) = {136, 141};
//+
Line(10) = {142, 135};
//+
Line(11) = {135, 134};
//+
Line(12) = {134, 136};
//+
Circle(13) = {142, 1, 141};
//+
Line(15) = {139, 134};
//+
Line(16) = {141, 77};
//+
Line(17) = {10, 142};

//+
Transfinite Curve {13, 1} = n_inlet Using Progression 1;
//+
Transfinite Curve {17, 11, 6, 7, 12, 16} = n_vert Using Progression r_vert;
//+
Transfinite Curve {10, 2, 3, 9} = n_af Using Progression 1;
//+
Transfinite Curve {5, 15, 8} = n_wake Using Progression r_wake;
//+
Curve Loop(1) = {13, 16, -1, 17};
//+
Plane Surface(1) = {1};
//+
Curve Loop(2) = {17, 10, 11, -2};
//+
Plane Surface(2) = {2};
//+
Curve Loop(3) = {11, -15, -6, -5};
//+
Plane Surface(3) = {3};
//+
Curve Loop(4) = {15, 12, -8, -7};
//+
Plane Surface(4) = {4};
//+
Curve Loop(5) = {3, 12, 9, 16};
//+
Plane Surface(5) = {5};
//+
Transfinite Surface {1};
//+
Transfinite Surface {2};
//+
Transfinite Surface {3};
//+
Transfinite Surface {4};
//+
Transfinite Surface {5};
//+
Recombine Surface {1, 2, 3, 4, 5};
//+
Extrude {0, 0, 1} {
Surface{1}; Surface{2}; Surface{3}; Surface{4}; Surface{5}; Layers {1}; Recombine;
}
//+
Physical Volume("internal", 128) = {1, 2, 3, 4, 5};
//+
Physical Surface("inlet", 129) = {26};
//+
Physical Surface("topAndBottom", 130) = {52, 82, 122, 100};
//+
Physical Surface("outlet", 131) = {78, 104};
//+
Physical Surface("airfoil", 132) = {60, 114, 34};
//+
Physical Surface("frontAndBack", 133) = {39, 61, 83, 105, 127, 1, 2, 5, 4, 3};


airfoil0012d.geo:
//+
Point(1) = {0,0,1.0};
//+
Point(2) = {0.0005839,0.0042603,1.0};
//+
Point(3) = {0.0023342,0.0084289,1.0};
//+
Point(4) = {0.0052468,0.0125011,1.0};
//+
Point(5) = {0.0093149,0.0164706,1.0};
//+
Point(6) = {0.0145291,0.02033,1.0};
//+
Point(7) = {0.0208771,0.0240706,1.0};
//+
Point(8) = {0.0283441,0.0276827,1.0};
//+
Point(9) = {0.0369127,0.0311559,1.0};
//+
Point(10) = {0.0465628,0.0344792,1.0};
//+
Point(11) = {0.057272,0.0376414,1.0};
//+
Point(12) = {0.0690152,0.040631,1.0};
//+
Point(13) = {0.0817649,0.0434371,1.0};
//+
Point(14) = {0.0954915,0.0460489,1.0};
//+
Point(15) = {0.1101628,0.0484567,1.0};
//+
Point(16) = {0.1257446,0.0506513,1.0};
//+
Point(17) = {0.1422005,0.0526251,1.0};
//+
Point(18) = {0.1594921,0.0543715,1.0};
//+
Point(19) = {0.1775789,0.0558856,1.0};
//+
Point(20) = {0.1964187,0.057164,1.0};
//+
Point(21) = {0.2159676,0.0582048,1.0};
//+
Point(22) = {0.2361799,0.0590081,1.0};
//+
Point(23) = {0.2570083,0.0595755,1.0};
//+
Point(24) = {0.2784042,0.0599102,1.0};
//+
Point(25) = {0.3003177,0.0600172,1.0};
//+
Point(26) = {0.3226976,0.0599028,1.0};
//+
Point(27) = {0.3454915,0.0595747,1.0};
//+
Point(28) = {0.3686463,0.0590419,1.0};
//+
Point(29) = {0.3921079,0.0583145,1.0};
//+
Point(30) = {0.4158215,0.0574033,1.0};
//+
Point(31) = {0.4397317,0.05632,1.0};
//+
Point(32) = {0.4637826,0.0550769,1.0};
//+
Point(33) = {0.4879181,0.0536866,1.0};
//+
Point(34) = {0.5120819,0.052162,1.0};
//+
Point(35) = {0.5362174,0.0505161,1.0};
//+
Point(36) = {0.5602683,0.0487619,1.0};
//+
Point(37) = {0.5841786,0.0469124,1.0};
//+
Point(38) = {0.6078921,0.0449802,1.0};
//+
Point(39) = {0.6313537,0.0429778,1.0};
//+
Point(40) = {0.6545085,0.0409174,1.0};
//+
Point(41) = {0.6773025,0.0388109,1.0};
//+
Point(42) = {0.6996823,0.03667,1.0};
//+
Point(43) = {0.7215958,0.0345058,1.0};
//+
Point(44) = {0.7429917,0.0323294,1.0};
//+
Point(45) = {0.7638202,0.0301515,1.0};
//+
Point(46) = {0.7840324,0.0279828,1.0};
//+
Point(47) = {0.8035813,0.0258337,1.0};
//+
Point(48) = {0.8224211,0.0237142,1.0};
//+
Point(49) = {0.8405079,0.0216347,1.0};
//+
Point(50) = {0.8577995,0.0196051,1.0};
//+
Point(51) = {0.8742554,0.0176353,1.0};
//+
Point(52) = {0.8898372,0.0157351,1.0};
//+
Point(53) = {0.9045085,0.0139143,1.0};
//+
Point(54) = {0.9182351,0.0121823,1.0};
//+
Point(55) = {0.9309849,0.0105485,1.0};
//+
Point(56) = {0.942728,0.0090217,1.0};
//+
Point(57) = {0.9534372,0.0076108,1.0};
//+
Point(58) = {0.9630873,0.0063238,1.0};
//+
Point(59) = {0.9716559,0.0051685,1.0};
//+
Point(60) = {0.9791229,0.0041519,1.0};
//+
Point(61) = {0.9854709,0.0032804,1.0};
//+
Point(62) = {0.990685,0.0025595,1.0};
//+
Point(63) = {0.9947532,0.0019938,1.0};
//+
Point(64) = {0.9976658,0.001587,1.0};
//+
Point(65) = {0.9994161,0.0013419,1.0};
//+
Point(66) = {1,0.00126,1.0};
//+
Point(68) = {0,0,1.0};
//+
Point(69) = {0.0005839,-0.0042603,1.0};
//+
Point(70) = {0.0023342,-0.0084289,1.0};
//+
Point(71) = {0.0052468,-0.0125011,1.0};
//+
Point(72) = {0.0093149,-0.0164706,1.0};
//+
Point(73) = {0.0145291,-0.02033,1.0};
//+
Point(74) = {0.0208771,-0.0240706,1.0};
//+
Point(75) = {0.0283441,-0.0276827,1.0};
//+
Point(76) = {0.0369127,-0.0311559,1.0};
//+
Point(77) = {0.0465628,-0.0344792,1.0};
//+
Point(78) = {0.057272,-0.0376414,1.0};
//+
Point(79) = {0.0690152,-0.040631,1.0};
//+
Point(80) = {0.0817649,-0.0434371,1.0};
//+
Point(81) = {0.0954915,-0.0460489,1.0};
//+
Point(82) = {0.1101628,-0.0484567,1.0};
//+
Point(83) = {0.1257446,-0.0506513,1.0};
//+
Point(84) = {0.1422005,-0.0526251,1.0};
//+
Point(85) = {0.1594921,-0.0543715,1.0};
//+
Point(86) = {0.1775789,-0.0558856,1.0};
//+
Point(87) = {0.1964187,-0.057164,1.0};
//+
Point(88) = {0.2159676,-0.0582048,1.0};
//+
Point(89) = {0.2361799,-0.0590081,1.0};
//+
Point(90) = {0.2570083,-0.0595755,1.0};
//+
Point(91) = {0.2784042,-0.0599102,1.0};
//+
Point(92) = {0.3003177,-0.0600172,1.0};
//+
Point(93) = {0.3226976,-0.0599028,1.0};
//+
Point(94) = {0.3454915,-0.0595747,1.0};
//+
Point(95) = {0.3686463,-0.0590419,1.0};
//+
Point(96) = {0.3921079,-0.0583145,1.0};
//+
Point(97) = {0.4158215,-0.0574033,1.0};
//+
Point(98) = {0.4397317,-0.05632,1.0};
//+
Point(99) = {0.4637826,-0.0550769,1.0};
//+
Point(100) = {0.4879181,-0.0536866,1.0};
//+
Point(101) = {0.5120819,-0.052162,1.0};
//+
Point(102) = {0.5362174,-0.0505161,1.0};
//+
Point(103) = {0.5602683,-0.0487619,1.0};
//+
Point(104) = {0.5841786,-0.0469124,1.0};
//+
Point(105) = {0.6078921,-0.0449802,1.0};
//+
Point(106) = {0.6313537,-0.0429778,1.0};
//+
Point(107) = {0.6545085,-0.0409174,1.0};
//+
Point(108) = {0.6773025,-0.0388109,1.0};
//+
Point(109) = {0.6996823,-0.03667,1.0};
//+
Point(110) = {0.7215958,-0.0345058,1.0};
//+
Point(111) = {0.7429917,-0.0323294,1.0};
//+
Point(112) = {0.7638202,-0.0301515,1.0};
//+
Point(113) = {0.7840324,-0.0279828,1.0};
//+
Point(114) = {0.8035813,-0.0258337,1.0};
//+
Point(115) = {0.8224211,-0.0237142,1.0};
//+
Point(116) = {0.8405079,-0.0216347,1.0};
//+
Point(117) = {0.8577995,-0.0196051,1.0};
//+
Point(118) = {0.8742554,-0.0176353,1.0};
//+
Point(119) = {0.8898372,-0.0157351,1.0};
//+
Point(120) = {0.9045085,-0.0139143,1.0};
//+
Point(121) = {0.9182351,-0.0121823,1.0};
//+
Point(122) = {0.9309849,-0.0105485,1.0};
//+
Point(123) = {0.942728,-0.0090217,1.0};
//+
Point(124) = {0.9534372,-0.0076108,1.0};
//+
Point(125) = {0.9630873,-0.0063238,1.0};
//+
Point(126) = {0.9716559,-0.0051685,1.0};
//+
Point(127) = {0.9791229,-0.0041519,1.0};
//+
Point(128) = {0.9854709,-0.0032804,1.0};
//+
Point(129) = {0.990685,-0.0025595,1.0};
//+
Point(130) = {0.9947532,-0.0019938,1.0};
//+
Point(131) = {0.9976658,-0.001587,1.0};
//+
Point(132) = {0.9994161,-0.0013419,1.0};
//+
Point(133) = {1,-0.00126,1.0};
//+
Point(134) = {1.005, 0, 1, 1.0};
//+
Line(1) = {10,9,8,7,6,5,4,3,2,1,69,70,69,70,71,72,73,74,75,7 6,77};
Line(2) = {10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,2 6,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42, 43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59 ,60,61,62,63,64,65,66,134};
Line(3) = {77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,9 3,94,95,96,97,98,99,100,101,102,103,104,105,106,10 7,108,109,110,111,112,113,114,115,116,117,118,119, 120,121,122,123,124,125,126,127,128,129,130,131,13 2,133,134};

Hii,
I suppose the number of divisions on the leading edge part is not equal to the number of divisions in c inlet (guessing from the photograph). If you use transfinite on the leading edge and make the no. of divisions equal, then the problem will be solved.

Regards,
Gaurav