fixed subdomain indices, CHANGED thermalCondicutivity of ceramic

This commit is contained in:
jakob.schratter 2026-01-26 11:25:52 +01:00
commit 4c5aa92fdd
4 changed files with 5384 additions and 5388 deletions

View file

@ -799,14 +799,14 @@ void Mesh::InitializeOuterEdges()
assert(EdgeSubdomains.size() == 2*_ebedges.size()); assert(EdgeSubdomains.size() == 2*_ebedges.size());
for (size_t k = 0; k < _ebedges.size(); ++k) // loop over all boundary edges for (size_t k = 0; k < _ebedges.size(); ++k) // loop over all boundary edges
{ {
if (EdgeSubdomains[2*k] == 0) if (EdgeSubdomains[2*k] == -1)
{ {
OuterEdges.push_back(_ebedges[k]); OuterEdges.push_back(_ebedges[k]);
OuterEdgesSubdomains.push_back(EdgeSubdomains[2*k + 1]); OuterEdgesSubdomains.push_back(EdgeSubdomains[2*k + 1]);
OuterEdgesNodes.push_back(_bedges[2*k]); OuterEdgesNodes.push_back(_bedges[2*k]);
OuterEdgesNodes.push_back(_bedges[2*k + 1]); OuterEdgesNodes.push_back(_bedges[2*k + 1]);
} }
if (EdgeSubdomains[2*k + 1] == 0) if (EdgeSubdomains[2*k + 1] == -1)
{ {
OuterEdges.push_back(_ebedges[k]); OuterEdges.push_back(_ebedges[k]);
OuterEdgesSubdomains.push_back(EdgeSubdomains[2*k]); OuterEdgesSubdomains.push_back(EdgeSubdomains[2*k]);
@ -1155,6 +1155,7 @@ void Mesh::ReadVertexBasedMesh(std::string const &fname)
for (int k = 0; k < nbedges * 2; ++k) for (int k = 0; k < nbedges * 2; ++k)
{ {
ifs >> EdgeSubdomains[k]; ifs >> EdgeSubdomains[k];
EdgeSubdomains[k] -= OFFSET;
} }
} }
else else

View file

@ -428,12 +428,13 @@ void FEM_Matrix::CalculateLaplace_mult(vector<double> &f)
double FEM_Matrix::ThermalConductivity(const int subdomain) double FEM_Matrix::ThermalConductivity(const int subdomain)
{ {
// source: https://www.engineeringtoolbox.com/thermal-conductivity-d_429.html
double lambda = 0.0; double lambda = 0.0;
switch (subdomain) switch (subdomain)
{ {
// ceramic mug // ceramic mug
case 0: case 0:
lambda = 4.0; // anything from 1 to 4 lambda = 6.0; // anything from 1 to 4
break; break;
// water // water
@ -447,7 +448,7 @@ double FEM_Matrix::ThermalConductivity(const int subdomain)
break; break;
default: default:
lambda = 1.0; assert(false && "BAD subdomain");
break; break;
} }
@ -456,6 +457,7 @@ double FEM_Matrix::ThermalConductivity(const int subdomain)
double FEM_Matrix::VolumetricHeatCapacity(const int subdomain) double FEM_Matrix::VolumetricHeatCapacity(const int subdomain)
{ {
// source? https://en.wikipedia.org/wiki/Table_of_specific_heat_capacities
double c = 0.0; double c = 0.0;
switch (subdomain) switch (subdomain)
{ {
@ -475,7 +477,7 @@ double FEM_Matrix::VolumetricHeatCapacity(const int subdomain)
break; break;
default: default:
c = 1.0; assert(false && "BAD subdomain");
break; break;
} }
@ -630,13 +632,13 @@ void FEM_Matrix::ApplyRobinBC_mult(std::vector<double> &f, const double u_out)
int const subdomain = RobinEdgesSubdomains[i]; int const subdomain = RobinEdgesSubdomains[i];
double const alpha = Heat_transfer_coefficient(subdomain); double const alpha = Heat_transfer_coefficient(subdomain);
//int const EdgeNumber = RobinEdges[i]; int const EdgeNumber = RobinEdges[i];
int const EdgeNode1 = RobinEdgeNodes[2*i]; int const EdgeNode1 = RobinEdgeNodes[2*i];
int const EdgeNode2 = RobinEdgeNodes[2*i + 1]; int const EdgeNode2 = RobinEdgeNodes[2*i + 1];
//cout << "Edge number " << EdgeNumber << ", subdomain: " << subdomain << " "; cout << "Edge number " << EdgeNumber << ", subdomain: " << subdomain << " ";
//cout << "Node1: " << EdgeNode1 << " Node2: " << EdgeNode2 << " " << endl; cout << "Node1: " << EdgeNode1 << " Node2: " << EdgeNode2 << " " << endl;
double x_1 = Coordinates[2*EdgeNode1]; double x_1 = Coordinates[2*EdgeNode1];
double y_1 = Coordinates[2*EdgeNode1 + 1]; double y_1 = Coordinates[2*EdgeNode1 + 1];
@ -666,35 +668,25 @@ void FEM_Matrix::ApplyRobinBC_mult(std::vector<double> &f, const double u_out)
return; return;
} }
// source: https://www.engineeringtoolbox.com/overall-heat-transfer-coefficient-d_434.html
double FEM_Matrix::Heat_transfer_coefficient(const int subdomain) double FEM_Matrix::Heat_transfer_coefficient(const int subdomain)
{ {
int matlab_sd_index = subdomain - 1;
double alpha = 0.0; double alpha = 0.0;
switch (matlab_sd_index) switch (subdomain)
{ {
// outside // ceramic to air
case 0: case 0:
alpha = 10.0;
break;
// ceramic
case 1:
alpha = 1.0; alpha = 1.0;
break; break;
// water // air to air (Free Convection Gas - Free Convection Gas : U = 1 - 2 W/m2K (typical window, room to outside air through glass))
case 2: case 2:
alpha = 500.0; alpha = 1.0;
break;
// air
case 3:
alpha = 10.0;
break; break;
default: default:
alpha = 1.0; assert(false && "BAD subdomain");
break; break;
} }

View file

@ -31,7 +31,7 @@ int main(int argc, char **argv )
// ########################################## // ##########################################
double dt = 1.0; // time step double dt = 1.0; // time step
//int steps = 200; // number of time iterations int steps = 100; // number of time iterations
double u0_mug = 18.0; double u0_mug = 18.0;
double u0_fluid = 80.0; double u0_fluid = 80.0;
@ -80,7 +80,9 @@ int main(int argc, char **argv )
auto t3 = system_clock::now(); // start timer auto t3 = system_clock::now(); // start timer
double average_cup_temperature = u0_mug; double average_cup_temperature = u0_mug;
while (average_cup_temperature < 67)
double time_count = 0;
while (average_cup_temperature < 67.0)
//for (int step = 0; step < steps; ++step) //for (int step = 0; step < steps; ++step)
{ {
vector<double> G(Mdt.Nrows(), 0.0); vector<double> G(Mdt.Nrows(), 0.0);
@ -96,7 +98,8 @@ int main(int argc, char **argv )
// ----- SK ----- ------ H ------- // ----- SK ----- ------ H -------
average_cup_temperature = mesh_c.AverageVectorFunction_perSubdomain(uv, 0); average_cup_temperature = mesh_c.AverageVectorFunction_perSubdomain(uv, 0);
cout << "Average cup temperature: " << average_cup_temperature << endl; cout << "Average cup temperature: " << average_cup_temperature << " after " << time_count << " seconds. " << endl;
time_count += dt;
} }
auto t4 = system_clock::now(); // stop timer auto t4 = system_clock::now(); // stop timer

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