sandbox/bugs/essai_discharge.h.c

    The goal of this script is to give an input discharge on the upstream boundary (left) thanks to “discharge.h”, with a one-dimensional grid. Unfortunately, it seems that “foreach_boundary()” (called by “discharge.h”) does not work together with “grid/cartesian-1D.h”, which causes a bug. Other bugs exist in this script, but the are apparently not linked with the bug caused by “discharge.h”. I published this bug report because I found out that someone had the same problem on the forum : [https://groups.google.com/g/basilisk-fr/c/AdkEEEVTXno/m/32Dxwc-XBQAJ].

    #include <math.h>
    
    #include "grid/cartesian1D.h"
    #include "saint-venant.h"
    
    #include "discharge.h"
    
    #define TMAX 12500. // time length of the simulation
    #define QBASE 1.65 // base flow
    
    #define MAX(a,b) (a > b ? a :b)

    Main constants and call to the solver.

    int main()
    {
        G  = 9.81;
        L0 = 3000.;
        X0 = 0.;
        N  = 256; 
        run();
    }

    The initial conditions : base flow ; the boundary conditions : closed upstream, open downstream.

    event init(t=0)
    {
    
        double h_base = 1.0291;
    
        foreach()
        {
            zb[]  = 0.;
            h[]   = h_base;
            u.x[] = QBASE / h_base;
         }
    
        h[left] = dirichlet(0);
        u.n[left] = dirichlet(0);
    
        h[right] = neumann(0);
        u.n[right] = neumann(0);
    
        boundary(all);
    
    }

    This paragraph gives the sinusoidal input discharge (left boundary). It uses “eta_b” from “discharge.h”, which itself calls “foreach_boundary()” and causes the main bug.

    event flows(i++) // mise a jour des CL
    {
    variable ‘eta_inj’ set but not used [-Wunused-but-set-variable]
        double q_inj, eta_inj;
        q_inj = QBASE + 0.8 * cos(t*6.28/50.);
    ‘eta_inj’ undeclared (first use in this function)
        eta_inj = eta_b(q_inj, left);
        h[left] = MAX(eta_inj - zb[], 0.);
    subscripted value is neither array nor pointer nor vector
    expected expression before ‘]’ token
        u.x[left] = q_inj / h[];
    
    }

    The next paragraphs are the outputs.

    event outputs_jx(i=1)
    {
        static FILE * tab_j_x = fopen( "compScilabDischarge.h.tab-j-x.csv", "write");
    
        int j = 0; // indice d'espace, j = 1:N
    
        foreach()
        {
            j += 1;
            fprintf(tab_j_x, "%d; %g;\n", j, x); // tableau avec le temps et les nos. d'iteration
        }
    
    
    }
    
    event outputs_tab(i++)
    {
        int j; // indice d'espace, j = 1:N
    
        static FILE * tab_i_t = fopen( "compScilabDischarge.h.tab-i-t.csv", "write");
    
        fprintf(tab_i_t, "%d; %g;\n", i, t); // tableau avec le temps et les nos. d'iteration
    
        static FILE * tab_h = fopen( "compScilabDischarge.h.tab-h.csv", "write");
    
        // ecriture des abscisses
        j = 0;
        foreach()
        {
            j += 1;
            fprintf(tab_h, (j < N ? "%g; " : "%g") , h[]);
        }
        fprintf(tab_h, "%s", "\n");
    
        static FILE * tab_u = fopen( "compScilabDischarge.h.tab-u.csv", "write");
    
        // ecriture des abscisses
        j = 0;
        foreach()
        {
            j += 1;
            fprintf(tab_u, (j < N ? "%g; " : "%g"), u.x[]);
        }
        fprintf(tab_u, "%s", "\n");
    
    
        static FILE * tab_zb = fopen( "compScilabDischarge.h.tab-zb.csv", "write");
    
        // ecriture des abscisses
        j = 0;
        foreach()
        {
            j += 1;
            fprintf(tab_zb, (j < N ? "%g; " : "%g"), zb[]);
        }
        fprintf(tab_zb, "%s", "\n");
    }

    End of the program.

    event end(t = TMAX)
    {
        printf("Programme termine : iteration no. %d ; temps : %g\n", i, t);
    }