added subdomain indexing for outer edges, for use in robin BC
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jakob.schratter
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5 changed files with 143 additions and 33 deletions
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@ -761,24 +761,25 @@ const std::vector<int> Mesh::BoundaryEdges() const
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// Only the outer edges for Robin BC
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const std::vector<int> Mesh::OuterEdges() const
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void Mesh::InitializeOuterEdges()
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{
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vector<int> outerEdges;
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for (int k = 0; k < _ebedges.size()/2; ++k)
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assert(EdgeSubdomains.size() == 2*_ebedges.size());
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for (size_t k = 0; k < _ebedges.size(); ++k) // loop over all boundary edges
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{
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if (EdgeSubdomains[k] == 0 || EdgeSubdomains[k + 1] == 0)
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outerEdges.push_back(_ebedges[k]);
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if (EdgeSubdomains[2*k] == 0)
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{
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OuterEdges.push_back(_ebedges[k]);
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OuterEdgesSubdomains.push_back(EdgeSubdomains[2*k + 1]);
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}
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if (EdgeSubdomains[2*k + 1] == 0)
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{
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OuterEdges.push_back(_ebedges[k]);
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OuterEdgesSubdomains.push_back(EdgeSubdomains[2*k]);
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}
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}
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cout << "All boundary edges: " << _ebedges.size() << endl;
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cout << "Outer boundary edges: " << outerEdges.size() << endl;
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// cout << _ebedges;
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// cout << endl;
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// cout << outerEdges << endl;
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return outerEdges;
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cout << "Outer boundary edges: " << OuterEdges.size() << endl;
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}
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@ -1017,6 +1018,7 @@ Mesh::Mesh(std::string const &fname)
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Mesh::Mesh(std::string const &filename, std::string const &subdomain_filename) : Mesh(filename)
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{
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ElementSubdomains = ReadElementSubdomains(subdomain_filename);
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InitializeOuterEdges();
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}
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@ -326,10 +326,15 @@ public:
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private:
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void Write_ascii_paraview_2D(std::string const &fname, std::vector<double> const &v) const;
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void Write_ascii_paraview_3D(std::string const &fname, std::vector<double> const &v) const;
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void InitializeOuterEdges();
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public:
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const std::vector<int> BoundaryEdges() const;
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const std::vector<int> OuterEdges() const;
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std::vector<int> OuterEdgesSubdomains;
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std::vector<int> OuterEdges;
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/**
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@ -565,8 +570,6 @@ public:
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*/
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[[nodiscard]] const std::vector<int> ReadElementSubdomains(std::string const &dname) const;
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[[nodiscard]] const std::vector<int> ReadEdgeSubdomains(std::string const &filename) const;
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/**
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* Calculates the largest inner angle in element @p idx.
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@ -412,7 +412,7 @@ void FEM_Matrix::CalculateLaplaceMult(vector<double> &f)
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auto subdomain = sd_vec[i];
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double lambda = ThermalConductivity(subdomain);
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cout << subdomain << endl;
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//cout << subdomain << endl;
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CalcElemSpecific(ia.data() + 3 * i, xc.data(), lambda, ske);
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//AddElem(ia.data()+3 * i, ske, fe, _id.data(), _ik.data(), _sk.data(), f.data()); // GH: deprecated
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@ -423,9 +423,6 @@ void FEM_Matrix::CalculateLaplaceMult(vector<double> &f)
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cout << "finished in " << duration << " sec. ########\n"; // ToDo: change to systemclock
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//Debug();
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return;
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}
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@ -583,6 +580,99 @@ void FEM_Matrix::ApplyDirichletBC(std::vector<double> const &u, std::vector<doub
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}
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void FEM_Matrix::ApplyRobinBC_mult(std::vector<double> const &u, std::vector<double> &f, const double u_out)
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{
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auto const RobinEdges = _mesh.OuterEdges;
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auto const RobinEdgesSubdomains = _mesh.OuterEdgesSubdomains;
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for (int i = 0; i < RobinEdges.size(); ++i)
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{
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cout << "Edge number " << RobinEdges[i] << ", subdomain: " << RobinEdgesSubdomains[i] << endl;
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}
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// Jakob Todo
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auto const idx = _mesh.Index_DirichletNodes(); // ALL boundary nodes
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const vector<int> sd_vec = _mesh.ElementSubdomains;
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for (int i = 0; i < idx.size(); ++i) {
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int const row = idx[i];
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int subdomain = sd_vec[row];
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// cout << "row: " << row;
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// cout << ", subdomain: " << subdomain << endl;
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double alpha = Heat_transfer_coefficient(subdomain);
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f[row] += u_out*alpha/2;
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for (int ij = _id[row]; ij < _id[row + 1]; ++ij)
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{
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int const col = _ik[ij];
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if(col == row)
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{
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_sk[ij] += alpha/3;
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}
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else
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{
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int const id1 = fetch(col, row); // Find entry (col,row)
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assert(id1 >= 0);
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_sk[id1] += alpha/6;
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}
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}
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}
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return;
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}
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double FEM_Matrix::Heat_transfer_coefficient(const int subdomain)
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{
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int matlab_sd_index = subdomain - 1;
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double alpha = 0.0;
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switch (matlab_sd_index)
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{
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// outside
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case 0:
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alpha = 1.0;
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break;
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// ceramic
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case 1:
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alpha = 1.0;
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break;
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// water
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case 2:
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alpha = 1.0;
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break;
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// air
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case 3:
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alpha = 1.0;
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break;
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default:
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alpha = 1.0;
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break;
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}
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return alpha;
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}
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void FEM_Matrix::AddElem_3(int const ial[3], double const ske[3][3], double const fe[3], vector<double> &f)
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{
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@ -394,6 +394,20 @@ class FEM_Matrix: public CRS_Matrix
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*/
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void ApplyDirichletBC(std::vector<double> const &u, std::vector<double> &f);
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/**
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* Applies Robin boundary conditions to stiffness matrix and to load vector @p f
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* for multiple subdomains
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* The <a href="https://www.jstor.org/stable/2005611?seq=1#metadata_info_tab_contents">penalty method</a>
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* is used for incorporating the given values @p u.
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*
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* @param[in] u (global) vector with Dirichlet data
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* @param[in] u_out outside temperature
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* @param[in,out] f load vector
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*/
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void ApplyRobinBC_mult(std::vector<double> const &u, std::vector<double> &f, const double u_out);
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double Heat_transfer_coefficient(const int subdomain);
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/**
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* Extracts the diagonal elements of the sparse matrix.
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*
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@ -20,24 +20,24 @@ int main(int argc, char **argv )
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#undef MG
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#ifndef MG
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// Jacobi iteration
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int nrefine = 0;
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if (argc > 1) nrefine = atoi(argv[1]);
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//int nrefine = 0;
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//if (argc > 1) nrefine = atoi(argv[1]);
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// generating the mesh
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Mesh const mesh_c("../generate_mesh/coffee_cup.txt", "../generate_mesh/coffee_cup_sd.txt");
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//Mesh const mesh_c("square_tiny.txt");
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bool ba = mesh_c.checkObtuseAngles();
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if (ba) cout << "mesh corrected" << endl;
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//mesh_c.DebugEdgeBased();
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gMesh_Hierarchy ggm(mesh_c, nrefine);
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const Mesh &mesh = ggm.finest();
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//gMesh_Hierarchy ggm(mesh_c, nrefine);
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//const Mesh &mesh = ggm.finest();
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//mesh.Debug();
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//mesh.DebugEdgeBased();
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// Initializing FEM matrix !pattern! (only zero entries now)
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FEM_Matrix SK(mesh); // CRS matrix
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FEM_Matrix SK(mesh_c); // CRS matrix
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//SK.writeBinary("sparseMatrix.bin");
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//SK.Debug();
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@ -50,19 +50,20 @@ int main(int argc, char **argv )
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//SK.Debug();
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// Calculate RHS
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SK.CalculateRHS(fv, [](double x, double y) { // rhs
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return std::sin(M_PI * 2.5 * y) * (M_PI * M_PI * 2.5 * 2.5 * x * x - 2); });
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// SK.CalculateRHS(fv, [](double x, double y) { // rhs
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// return std::sin(M_PI * 2.5 * y) * (M_PI * M_PI * 2.5 * 2.5 * x * x - 2); });
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SK.CalculateRHS(fv, [](double x, double y) {return 0;});
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//SK.CheckRowSum();
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SK.CheckMatrix();
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// Initialize temperature
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vector<double> uv(SK.Nrows(), 0.0); // temperature
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mesh.Init_Solution_mult(uv, 0, [](double x, double y) -> double { return 18; }); // mug
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mesh.Init_Solution_mult(uv, 1, [](double x, double y) -> double { return 80; }); // fluid
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mesh.Init_Solution_mult(uv, 2, [](double x, double y) -> double { return 18; }); // air
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mesh_c.Init_Solution_mult(uv, 0, [](double x, double y) -> double { return 18; }); // mug
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mesh_c.Init_Solution_mult(uv, 1, [](double x, double y) -> double { return 80; }); // fluid
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mesh_c.Init_Solution_mult(uv, 2, [](double x, double y) -> double { return 18; }); // air
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// Apply BC
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SK.ApplyDirichletBC(uv, fv);
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SK.ApplyRobinBC_mult(uv, fv, 18.0);
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// Solve
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@ -83,7 +84,7 @@ int main(int argc, char **argv )
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auto [val, idx] = findLargestAbsError(exact_sol, uv, 1e+6, 100);
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//mesh.Visualize(getAbsError(exact_sol, uv));
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mesh.Visualize(uv);
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mesh_c.Visualize(uv);
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#else
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// multigrid iteration
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