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ME 602

Computational Fluid Dynamics

Assignment 02

Submitted By:

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#include

#include#include

#include

usingnamespacestd;

enum{imax=129,jmax=129,Re=100,itr_si_max=10,itr_w_max =2,U=1};

//imax = max grid pt. starting frm 1 in x dir//jmax=max grid pt. starting frm 1 in y dir

//U =non dimentional vel of lid (at the top wall)

//Re=reynolds no fr the expt.

//itr_si_ma=no of itr for si//itr_w_max=no of itr fr omega

longdoublesi[150][150], u[150][150], v[150][150], omeg[150][150], Er,dx, dy, omeg_prev,si_prev;

inti, j,itr_si, itr_w, counter=0;

//calc the grid spacing

voidcalc_grid_spacing(){

dx = 1.0/(imax-1);

dy = 1.0/(jmax-1);

}

//setting the initial boundry conditions

voidinitialize_BC()

{for(i=1;i

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for(j=1;j

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Er += fabs(si[i][j]) - fabs(si_prev);

}

}

}

//iterating for the value of u & vfor(j=jmax-1;j>1;j--){

for(i=imax-1;i>1;i--)

{u[i][j] = (si[i][j+1] - si[i][j-1])/(2*dy);

v[i][j] = (si[i-1][j] - si[i+1][j])/(2*dx);

}

}

//iteration for the value of omega over the domain

for(itr_w=0;itr_w1;j--)

{

for(i=imax-1;i>1;i--){

omeg_prev = omeg[i][j];

omeg[i][j] = (omeg[i+1][j]*(1-(u[i][j]*dx*Re)/2) + omeg[i-1][j]*(1+(u[i][j]*dx*Re)/2) +\

omeg[i][j+1]*(1-(v[i][j]*dx*Re)/2) + omeg[i][j-1]*(1+(v[i][j]*dx*Re/2)))/4;}

}

}

//updating the boundry cond. over the wallsfor(i=2;i

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}

voidoutput(void){

FILE *fp_u, *fp_tab, *fp_v, *fp_si;

fp_u = fopen("u.txt", "w");

fp_v = fopen("v.txt", "w");

fp_si = fopen("si.txt", "w");fp_tab = fopen("table.txt", "w");

printf("no of itr=%d\n", counter);

//printing the required values to file

//for printing u along vertical line through geometric centre of the cavity

fprintf(fp_u,"y\t\tu\n\n");for(j=1;j

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fclose(fp_u);fclose(fp_v);

fclose(fp_si);

//printing the output for comparison with ghia et al.

fprintf(fp_tab," u-velocity\n\n");

fprintf(fp_tab,"129\t%lf\t\n",u[65][129]);fprintf(fp_tab,"126\t%lf\t\n",u[65][126]);

fprintf(fp_tab,"125\t%lf\t\n",u[65][125]);

fprintf(fp_tab,"124\t%lf\t\n",u[65][124]);

fprintf(fp_tab,"123\t%lf\t\n",u[65][123]);fprintf(fp_tab,"110\t%lf\t\n",u[65][110]);

fprintf(fp_tab,"95\t%lf\t\n",u[65][95]);

fprintf(fp_tab,"80\t%lf\t\n",u[65][80]);fprintf(fp_tab,"65\t%lf\t\n",u[65][65]);

fprintf(fp_tab,"59\t%lf\t\n",u[65][59]);

fprintf(fp_tab,"37\t%lf\t\n",u[65][37]);

fprintf(fp_tab,"23\t%lf\t\n",u[65][23]);fprintf(fp_tab,"14\t%lf\t\n",u[65][14]);

fprintf(fp_tab,"10\t%lf\t\n",u[65][10]);

fprintf(fp_tab,"9\t%lf\t\n",u[65][9]);fprintf(fp_tab,"8\t%lf\t\n",u[65][8]);

fclose(fp_tab);

}

voidmain()

{

calc_grid_spacing();initialize_BC();

init_sol_domain();

stream();output();

system("PAUSE");

}