!--------------------------------------------------------------------------
   !---------------------------- caldyn_slow_hydro ----------------------------------
   DO l = ll_begin, ll_end
      !DIR$ SIMD
      DO ij=ij_begin_ext, ij_end_ext
         uu = .5*(rhodz(ij,l)+rhodz(ij+t_right,l))*u(ij+u_right,l)
         hflux(ij+u_right,l) = uu*le_de(ij+u_right)
         uu = .5*(rhodz(ij,l)+rhodz(ij+t_lup,l))*u(ij+u_lup,l)
         hflux(ij+u_lup,l) = uu*le_de(ij+u_lup)
         uu = .5*(rhodz(ij,l)+rhodz(ij+t_ldown,l))*u(ij+u_ldown,l)
         hflux(ij+u_ldown,l) = uu*le_de(ij+u_ldown)
      END DO
   END DO
   DO l = ll_begin, ll_end
      !DIR$ SIMD
      DO ij=ij_begin, ij_end
         ke=0.d0
         ke = ke + le_de(ij+u_rup)*u(ij+u_rup,l)**2
         ke = ke + le_de(ij+u_lup)*u(ij+u_lup,l)**2
         ke = ke + le_de(ij+u_left)*u(ij+u_left,l)**2
         ke = ke + le_de(ij+u_ldown)*u(ij+u_ldown,l)**2
         ke = ke + le_de(ij+u_rdown)*u(ij+u_rdown,l)**2
         ke = ke + le_de(ij+u_right)*u(ij+u_right,l)**2
         BERNI(ij,l)=ke*(.25/Ai(ij))
      END DO
   END DO
   IF(zero) THEN
      DO l = ll_begin, ll_end
         !DIR$ SIMD
         DO ij=ij_begin, ij_end
            du(ij+u_right,l) = ne_right*(berni(ij,l)-berni(ij+t_right,l)) ! minus gradient
            du(ij+u_lup,l) = ne_lup*(berni(ij,l)-berni(ij+t_lup,l)) ! minus gradient
            du(ij+u_ldown,l) = ne_ldown*(berni(ij,l)-berni(ij+t_ldown,l)) ! minus gradient
         END DO
      END DO
   ELSE
      DO l = ll_begin, ll_end
         !DIR$ SIMD
         DO ij=ij_begin, ij_end
            du(ij+u_right,l) = du(ij+u_right,l) + ne_right*(berni(ij,l)-berni(ij+t_right,l)) ! minus gradient
            du(ij+u_lup,l) = du(ij+u_lup,l) + ne_lup*(berni(ij,l)-berni(ij+t_lup,l)) ! minus gradient
            du(ij+u_ldown,l) = du(ij+u_ldown,l) + ne_ldown*(berni(ij,l)-berni(ij+t_ldown,l)) ! minus gradient
         END DO
      END DO
   END IF
   !---------------------------- caldyn_slow_hydro ----------------------------------
   !--------------------------------------------------------------------------