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#include<iostream>
#include<cmath>
#include <fstream>
using namespace std;
#define DimX 9 //number of X nodes
#define DimY 9 //number of Y nodes
#define Dimt 10000 //time step
typedef long double real;
real T[DimX][DimY][Dimt];
int k;
void save_array_to_TXT(std::string nazwaPliku)
{
std::fstream plik;
plik.open(nazwaPliku, std::ios::out);
plik.precision(10);
for (k = 0; k < Dimt; k++)
{
for (int j = 0; j < DimY + 1; j++)
{
for (int i = 0; i < DimX + 1; i++)
{
plik << T[i][j][k] << " ";
}
plik << endl;
}
}
plik << endl;
plik.close();
}
void show_MAP()
{
for (int j = 0; j < DimY + 1; j++)
{
for (int i = 0; i < DimX + 1; i++)
{
cout.precision(17);
cout << T[i][j][k] << " ";
}
cout << endl;
}
cout << "after your click the button current map will dissapear" << endl;
system("pause");
system("cls");
}
void The_BEGINNING_CONDITION()
{
//THE BEGINNING CONDITION FOR TIIME t=0 , each node has temperature T[i][j][k]=273K = 0 Celcius degree
for (int i = 0; i < DimX + 1; i++)
{
for (int j = 0; j < DimY + 1; j++)
{
T[i][j][0] = 273;
}
}
}
void numerical_method(real t, real alfa, real lambda1, real Cp1, real ro1, real LengthXandY, real Tair)
//alfa is convection coefficient , for air(natural convection) alfa=5-25 W/(K*m^2)
{
real a1 = lambda1 / (Cp1*ro1);
real dl = LengthXandY / (DimX - 1); //dl=dx=dy
real dt;
dt = t / Dimt;
cout << "dt= " << dt << endl;
system("pause");
//stability condition
if (((lambda1*dt) / (ro1*Cp1*dl*dl)) > 0.25) // aby warunek byl spelniony Dimt musi byc dostatecznie duzy
{
cout << "(lambda1*dt) / (ro1*Cp1*dh*dh)= " << (lambda1*dt) / (ro1*Cp1*dl*dl) << endl;
cout << "error" << endl;
system("pause");
}
The_BEGINNING_CONDITION();
show_MAP();
real tal;
tal = (dt*lambda1) / (dl*dl*ro1*Cp1);
for ( k = 0; k < Dimt+1 ; k++)
{
for (int j = 0; j < DimY+1; j++)
{
for (int i = 0; i < DimX+1; i++)
{
//LEFT TOP COURNER
if ((i == 0) && (j == 0))
{
T[0][0][k + 1] = T[0][0][k]+tal*(Tair+Tair+T[0][1][k]+T[1][0][k]-4*T[0][0][k]) ;
}
//RIGHT TOP COURNER
if ((i == DimX) && (j == 0))
{
T[DimX][0][k + 1] = T[DimX][0][k] + tal*(Tair + Tair + T[DimX-1][0][k] + T[DimX][1][k] - 4 * T[DimX][0][k]);
}
//LEFT BOT CURNER
if ((i == 0) && (j == DimY))
{
T[0][DimY][k + 1] = T[0][DimY][k] + tal*(Tair + Tair + T[0][DimY - 1][k] + T[1][DimY][k] - 4*T[0][DimY][k]);
//THIS IS HERE!!!!!!!!!!!!!!!!!!
cout << "T[0][DimY][k + 1]= " << T[0][DimY][k + 1] << endl;
cout << "T[1][0][k + 1]= " << T[1][0][k + 1] << endl;
T[0][DimY][k + 1] = 999;
if (T[1][0][k + 1] == 999)
{
//How is that possible that assigning for element T[0][DimY][k + 1] for example value 999 that value is also assigning for T[1][0][k + 1]?
cout << "blad" << endl;
cout << "T[0][DimY][k + 1]= " << T[0][DimY][k + 1] << endl;
cout << "T[1][0][k + 1]= " << T[1][0][k + 1] << endl;
system("pause");
}
//T[0][DimY][k + 1] = T[0][DimY][k] + tal*(Tair + Tair + T[0][DimY - 1][k] + T[1][DimY][k] - 4 * T[0][DimY][k]);
}
//RIGHT BOT COURNER
if ((i == DimX) && (j == DimY))
{
T[DimX][DimY][k + 1] = T[DimX][DimY][k] + tal*(Tair + Tair + T[DimX - 1][DimY][k] + T[DimX][DimY - 1][k] - 4 * T[DimX][DimY][k]);
}
//TOP LINE
if ((j == 0) && (i != 0) && (i != DimX))
{
T[i][0][k + 1] = T[i][0][k] + tal*(Tair + T[i - 1][0][k] + T[i + 1][0][k] + T[i][1][k] - 4 * T[i][0][k]);
}
//BOT LINE
if ((j == DimY) && (i != 0) && (i != DimX))
{
T[i][DimY][k + 1] = T[i][DimY][k] + tal*(Tair + T[i - 1][DimY][k] + T[i + 1][DimY][k] + T[i][DimY-1][k] - 4 * T[i][DimY][k]);
}
//LEFT LINE
if ((i == 0) && (j != 0) && (j != DimY))
{
T[0][j][k + 1] = T[0][j][k] + tal*(Tair + T[0][j - 1][k] + T[0][j + 1][k] + T[1][j][k] - 4 * T[0][j][k]);
}
//RIGHT LINE
if ((i == DimX) && (j != 0) && (j != DimY))
{
T[DimX][j][k + 1] = T[DimX][j][k] + tal*(Tair + T[DimX][j - 1][k] + T[DimX][j + 1][k] + T[DimX - 1][j][k] - 4 * T[DimX][j][k]);
}
//REST OF NODES BASED ON PLATE
if ((i < DimX) && (i>0) && (j < DimY) && (j>0))
{
T[i][j][k + 1] = T[i][j][k] + tal*( T[i][j - 1][k] + T[i][j + 1][k] + T[i- 1][j][k]+T[i+1][j][k] - 4 * T[i][j][k]);
/*cout << "node (" << i << ")(" << j << ")" << endl;
cout << "T[i][j][k]=" << T[i][j][k] << endl;
cout << "tal*( T[i][j - 1][k] + T[i][j + 1][k] + T[i- 1][j][k]+T[i+1][j][k] - 4 * T[i][j][k])" << tal*(T[i][j - 1][k] + T[i][j + 1][k] + T[i - 1][j][k] + T[i + 1][j][k] - 4 * T[i][j][k]) << endl;
system("pause");
*/
}
}
}
cout << "t= " << k*dt << endl;
show_MAP();
}
save_array_to_TXT("results2d.txt");
}
int main()
{
numerical_method(1000,0.025,0.03,1,1,10,300);
system("pause");
}
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