  We simulate solid particles moving in the two-dimensional channel with the
Poiseuille flow. We found that the collective chain excitation emerges with the
increasing number of particles in the chain. We measured the spectrum of the
chain oscillations varying the width of the channel and found the spectrum
intensity became sharper for the more significant confinement ratio. The
simulations were done using the Immersed boundary and Lattice Boltzmann
methods. We compare our results with the experiments of the drop movement in
the quasi-two-dimensional channel and with the simulations of other groups. The
paper's main result is that the combination of the velocity gradient in
Poiseuille flow and the proximity of the particle to the wall can induce the
collective excitations in the chain of the particles moving in the
two-dimensional channel.
