boxlen = 2.0; boxwidth = 0.8; cylinderradius = 0.07; cylinderxpos = 0.25; // Tiny misalignment: cylinderypos = boxwidth/2 + boxwidth/1000; lc = 0.02; lcfine = 0.002; Point(1) = {0,0,0, lc}; Point(2) = {boxlen,0,0, lc}; Point(3) = {boxlen,boxwidth,0, lc}; Point(4) = {0,boxwidth,0, lc}; Point(5) = {cylinderxpos,cylinderypos,0, lcfine}; Point(6) = {cylinderxpos+cylinderradius,cylinderypos,0, lcfine}; Point(7) = {cylinderxpos,cylinderypos+cylinderradius,0, lcfine}; Point(8) = {cylinderxpos-cylinderradius,cylinderypos,0, lcfine}; Point(9) = {cylinderxpos,cylinderypos-cylinderradius,0, lcfine}; Line(1) = {1, 2}; Line(2) = {2, 3}; Line(3) = {3, 4}; Line(4) = {4, 1}; Circle(5) = {6, 5, 7}; Circle(6) = {7, 5, 8}; Circle(7) = {8, 5, 9}; Circle(8) = {9, 5, 6}; Line Loop(1) = {4, 1, 2, 3}; Line Loop(2) = {6, 7, 8, 5}; Plane Surface(1) = {1, 2}; Plane Surface(2) = {2}; fluid = 1; cylinder = 2; inlet = 3; outlet = 4; Physical Surface(fluid) = 1; Physical Surface(cylinder) = 2; Physical Line(inlet) = 4; Physical Line(outlet) = 2;