19 August 2018 03:16:02 PM FEM2D_NAVIER_STOKES C++ version: Compiled on Aug 19 2018 at 14:18:58. Finite element solution of the steady incompressible Navier Stokes equations on a triangulated region in 2 dimensions.' - nu * ( Uxx + Uyy ) + UUx + VUy + dPdx = F1(x,y) - nu * ( Vxx + Vyy ) + UVx + VVy + dPdy = F2(x,y) Ux + Vy = F3(x,y). Boundary conditions may be of Dirichlet type: U(x,y) = U_BC(x,y) V(x,y) = V_BC(x,y) P(x,y) = P_BC(x,y) or of Neumann type with zero right hand side: dU/dn(x,y) = 0 dV/dn(x,y) = 0 dP/dn(x,y) = 0 The finite element method uses Taylor-Hood triangular elements which are linear for pressure and quadratic for velocity. Maximum number of Newton iterations IT_MAX = 5 Quadrature order = 7 The kinematic viscosity NU = 1 Current status: * testing zero Neumann condition option. Node file is "nodes6.txt". Element file is "triangles6.txt". Number of nodes = 65 First 10 nodes Row: 1 2 Col 1 0 0 2 0 0.25 3 0 0.5 4 0 0.75 5 0 1 6 0.25 0 7 0.25 0.25 8 0.25 0.5 9 0.25 0.75 10 0.25 1 Element order = 6 Number of elements = 24 First 10 elements Row: 1 2 3 4 5 6 Col 1 1 11 3 6 7 2 2 13 3 11 8 7 12 3 3 13 5 8 9 4 4 15 5 13 10 9 14 5 11 21 13 16 17 12 6 23 13 21 18 17 22 7 13 23 15 18 19 14 8 25 15 23 20 19 24 9 21 31 23 26 27 22 10 33 23 31 28 27 32 Dirichlet boundary condition on pressure will be applied at node 1 Number of Neumann conditions added = 6 Boundary conditions per node: Node U_cond V_cond P_cond 0 2 2 2 1 2 2 0 2 2 2 1 3 2 2 0 4 2 2 1 5 2 2 0 6 1 1 0 7 1 1 0 8 1 1 0 9 2 2 0 10 2 2 1 11 1 1 0 12 1 1 1 13 1 1 0 14 2 2 1 15 2 2 0 16 1 1 0 17 1 1 0 18 1 1 0 19 2 2 0 20 2 2 1 21 1 1 0 22 1 1 1 23 1 1 0 24 2 2 1 25 2 2 0 26 1 1 0 27 1 1 0 28 1 1 0 29 2 2 0 30 2 2 1 31 1 1 0 32 1 1 1 33 1 1 0 34 2 2 1 35 2 2 0 36 1 1 0 37 1 1 0 38 1 1 0 39 2 2 0 40 2 2 1 41 1 1 0 42 1 1 1 43 1 1 0 44 2 2 1 45 2 2 0 46 1 1 0 47 1 1 0 48 1 1 0 49 2 2 0 50 2 2 1 51 1 1 0 52 1 1 1 53 1 1 0 54 2 2 1 55 2 2 0 56 1 1 0 57 1 1 0 58 1 1 0 59 2 2 0 60 2 2 1 61 3 3 0 62 3 3 1 63 3 3 0 64 2 2 1 Total number of variables is 151 Variable indices per node: Node U_index V_index P_index 1 1 2 3 2 4 5 -1 3 6 7 8 4 9 10 -1 5 11 12 13 6 14 15 -1 7 16 17 -1 8 18 19 -1 9 20 21 -1 10 22 23 -1 11 24 25 26 12 27 28 -1 13 29 30 31 14 32 33 -1 15 34 35 36 16 37 38 -1 17 39 40 -1 18 41 42 -1 19 43 44 -1 20 45 46 -1 21 47 48 49 22 50 51 -1 23 52 53 54 24 55 56 -1 25 57 58 59 26 60 61 -1 27 62 63 -1 28 64 65 -1 29 66 67 -1 30 68 69 -1 31 70 71 72 32 73 74 -1 33 75 76 77 34 78 79 -1 35 80 81 82 36 83 84 -1 37 85 86 -1 38 87 88 -1 39 89 90 -1 40 91 92 -1 41 93 94 95 42 96 97 -1 43 98 99 100 44 101 102 -1 45 103 104 105 46 106 107 -1 47 108 109 -1 48 110 111 -1 49 112 113 -1 50 114 115 -1 51 116 117 118 52 119 120 -1 53 121 122 123 54 124 125 -1 55 126 127 128 56 129 130 -1 57 131 132 -1 58 133 134 -1 59 135 136 -1 60 137 138 -1 61 139 140 141 62 142 143 -1 63 144 145 146 64 147 148 -1 65 149 150 151 The matrix half bandwidth is 25 The matrix bandwidth is 51 The storage bandwidth is 76 Order 6 nodes plotted in "nodes6.eps". Order 6 triangles plotted in "triangles6.eps". Pressure nodes written to "nodes3.txt". Pressure triangles written to "triangles3.txt". l2-norm of FEM residual = 1.28019 l2-norm of adjusted FEM residual = 2.61618e-14 Convergence. Solution to the NAVIER STOKES Equations: Node U V P 0 0 0 10 1 0.1875 8.32667e-17 2 0.25 -0 10 3 0.1875 -2.498e-16 4 0 0 10 5 0 0 6 0.1875 5.74193e-13 7 0.25 1.40628e-14 8 0.1875 -4.05925e-15 9 0 0 10 0 -0 9 11 0.1875 -3.07431e-14 12 0.25 2.87237e-14 9 13 0.1875 7.47903e-14 14 0 0 9 15 4.996e-16 0 16 0.1875 -8.29512e-14 17 0.25 2.70516e-14 18 0.1875 4.23138e-14 19 0 0 20 0 0 8 21 0.1875 -1.69508e-14 22 0.25 -6.6602e-15 8 23 0.1875 -1.25081e-14 24 0 0 8 25 -0 0 26 0.1875 1.06638e-15 27 0.25 -1.04145e-14 28 0.1875 -1.34215e-14 29 0 0 30 0 0 7 31 0.1875 7.97169e-15 32 0.25 2.28377e-16 7 33 0.1875 -2.59113e-17 34 0 0 7 35 -0 0 36 0.1875 4.11128e-15 37 0.25 2.01857e-15 38 0.1875 2.49373e-15 39 0 0 40 0 0 6 41 0.1875 -1.72547e-15 42 0.25 6.34575e-16 6 43 0.1875 1.50216e-15 44 0 0 6 45 -0 0 46 0.1875 -1.78911e-15 47 0.25 5.66503e-17 48 0.1875 4.45544e-16 49 0 0 50 0 0 5 51 0.1875 -4.77301e-16 52 0.25 -4.06083e-16 5 53 0.1875 -4.53386e-16 54 0 0 5 55 1.66533e-16 0 56 0.1875 1.38481e-16 57 0.25 -5.26027e-17 58 0.1875 -2.28813e-16 59 0 0 60 0 0 4 61 0.1875 4.04259e-16 62 0.25 1.70221e-16 4 63 0.1875 6.5553e-17 64 0 0 4 Navier Stokes pressures written to "pressure3.txt". Navier Stokes velocities written to "velocity6.txt". FEM2D_NAVIER_STOKES: Normal end of execution. 19 August 2018 03:16:02 PM