Numerical study of dust-ion-acoustic solitary waves in an inhomogeneous plasma

The hydrodynamic equations describing the propagation of nonlinear dust-ion-acoustic solitary waves in an inhomogeneous dusty plasma are solved numerically, taking into consideration dust charging process. Equilibrium plasma densities and dust charge are assumed to be spatially nonuniform, but dust number density is taken to be uniform. It is shown that wave evolutions depend sensitively on the plasma density distributions and electron-to-ion density ratios. Numerical results show that an initial solitary pulse evolves into a dispersive pulse with an oscillatory tail when the wave propagates from high- into low-density region and whereas the pulse can keep its shape when it propagates in the opposite direction. The dust charging process results in the damping of the solitary pulses.