Hello Guillaume, Thank you so much for you help.
Can I extend the same boundary layer into wake region? I tried doing the same by drawing a line from trailing edge to farfield and creating boundary layer around it. But I have not succeeded yet. -- With Regards Ashish On Tue, Jul 12, 2016 at 12:36 PM, DILASSER Guillaume < [email protected]> wrote: > Hello Ashish, > > > > You can add to the BoundaryLayer definition the property > “Field[1].FanNodesList = {1,n} ;” to get rid of the weird behavior of the > mesh around the tips of the foil. Somehow, the 2D blossom recombination > algorithm does not like when you do that so replace it with the standard > one using “Mesh.RecombinationAlgorithm = 0 ;”. Both modifications are done > in the enclosed file. Finally, you may want to increase the mesh density at > the front of the foil to better match the geometry there. > > > > Sincerely Yours, > > > > Guillaume DILASSER > > Doctorant SACM / LEAS > > CEA - Centre de Saclay - Bât.123 - PC 319c > > 91191 Gif sur Yvette Cedex - France - > > > > [email protected] > > > > > > *De :* gmsh [mailto:[email protected]] *De la part > de* ashish bhole > *Envoyé :* lundi 11 juillet 2016 19:02 > *À :* [email protected] > *Objet :* [Gmsh] Problem with Boundary Layer around 2D airfoil with sharp > trailing edge > > > > Hello All, > > I am new at using gmsh. I want to generate a mesh (unstructured) around 2D > airfoil with sharp trailing edge. When I use Boundary Layer field in gmsh, > it generates boundary layer but with undesirable intersections. I have > attached my .geo file here. Currently, I have commented Boundary Layer > field lines in the script. > > Please share idea how can I make it work correctly. > > Thank you. > > ------------------------------------ > Mesh.RecombineAll = 1; > > Li = 50.0; // distance of inflow boundary from origin > Lo = 50.0; // distance of outflow boundary from origin > > n = 50; // points on upper/lower surface of airfoil used to define airfoil > // These points may not appear in the mesh. > > lc1 = 10.0; > lc2 = 0.05; > > m = 2*n - 2; // total number of points on airfoil without repetition > // LE and TE points are common to upper/lower surface > > nle = n; // point number of LE = no. of points on upper surface > // Point(1) is trailing edge > > // NACA0012 profile > // formula taken from http://turbmodels.larc.nasa.gov/naca0012_val.html > Macro NACA0012 > x2 = x * x; > x3 = x * x2; > x4 = x * x3; > y = 0.594689181*(0.298222773*Sqrt(x) > - 0.127125232*x - 0.357907906*x2 + 0.291984971*x3 - 0.105174606*x4); > Return > > // put points on upper surface of airfoil > For i In {1:n} > theta = Pi * (i-1) / (n-1); > x = 0.5 * (Cos(theta) + 1.0); > Call NACA0012; > Point(i) = {x, y, 0.0, lc2}; > xx[i] = x; > yy[i] = y; > EndFor > > // put points on lower surface of airfoil, use upper surface points and > reflect > For i In {n+1:m} > Point(i) = {xx[2*n-i], -yy[2*n-i], 0.0, lc2}; > EndFor > > Spline(1) = {1:n}; > Spline(2) = {n:m, 1}; > > Point(1000) = {1.0, Li, 0.0,lc1}; > Point(1001) = {0.0, Li, 0.0,lc1}; > Point(1002) = {-Li, 0.0, 0.0,lc1}; > Point(1003) = {0.0, -Li, 0.0,lc1}; > Point(1004) = {1.0, -Li, 0.0,lc1}; > > Point(1005) = {Lo, 0.0, 0.0,lc1}; > Point(1006) = {Lo, Li, 0.0,lc1}; > Point(1007) = {Lo, -Li, 0.0,lc1}; > > Line(5) = {1000, 1001}; > Circle(6) = {1001, nle, 1002}; > Circle(7) = {1002, nle, 1003}; > Line(8) = {1003, 1004}; > Line(13) = {1005, 1006}; > Line(14) = {1005, 1007}; > Line(15) = {1006, 1000}; > Line(16) = {1007, 1004}; > > Line Loop(1) = {1,2}; > Line Loop(2) = {5,6,7,8,-16,-14,13,15}; > > Plane Surface(201) = {2,1}; > > /* > //Define Boundary Layer > Field[1] = BoundaryLayer; > Field[1].EdgesList = {1,2}; > Field[1].NodesList = {1,m}; > Field[1].hfar = 0.05; > Field[1].hwall_n = 0.009; > Field[1].thickness = 0.2; > Field[1].ratio = 1.1; > Field[1].AnisoMax = 10; > Field[1].Quads = 1; > Field[1].IntersectMetrics = 0; > BoundaryLayer Field = 1; > */ > ------------------------------------ > > -- With Reagrds > > Ashish Bhole >
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