UDF对边界附近的单元赋值

[zzZZZ]

请教各位，该怎么对边界附近的单元赋值，比如下面这个UDF.我想将一个区域的 C_UDMI(c, tt, 0)全部设置为0，然后边界附近的 C_UDMI(c, tt, 0)设置为1，该怎么操作？谢谢！

void set_zone(Thread* t)
{
    cell_t c;
    real vol;
    Thread *tt = THREAD_SUPER_THREAD(t);
    begin_c_loop(c, t)
    {
        if (THREAD_ID(t) == 1047) { 
            C_UDMI(c, tt, 0) = 1;
    }
    end_c_loop(c, lct)
}


void set_cells(Thread *t)
{


    Thread *tt = THREAD_SUPER_THREAD(t);
    face_t f;
    Thread *t_nbr;
    cell_t c0, c1;
    Domain *mix_domain = Get_Domain(1);

    for (int i = 0; i < num_boundaries; i++) {
        t_nbr = Lookup_Thread(mix_domain, 1);

        begin_f_loop(f, t_nbr){
            c0 = F_C0(f, t_nbr);
            c1 = F_C1(f, t_nbr);
            if (c0 != -1 && THREAD_ID(THREAD_T0(t_nbr)) == 1047) {
                C_UDMI(c0, tt, 1) = 0.0; 
            }

            if (c1 != -1 && THREAD_ID(THREAD_T1(t_nbr)) == 1047) {
                C_UDMI(c1, tt, 1) = 0.0;
            }
        }
        end_f_loop(f, t_nbr)
    }
}

DEFINE_ADJUST(aaa, mix_domain)
{
    Thread* mix_thread;
    int phase_domain_index = 0;

    thread_loop_c(mix_thread, mix_domain)
    {
        Thread* t = THREAD_SUB_THREAD(mix_thread, phase_domain_index);
        if (t != NULL) {
            set_capillary_pressure_sources(t);
            set_boundary_cells(t);
        }
    }
}