الفهرس | Only 14 pages are availabe for public view |
Abstract Effect of nonthermality of ions on the propagation of dust-acoustic waves (DAWs) in unmagnetized plasma having electrons, singly charged ions, hot and cold dust grains have been investigated. The reductive perturbation method is employed to reduce the basic set of fluid equations to the Kortewege-de Vries (KdV) equation. At the critical hot dusty plasma density, the KdV equation is not appropriate for describing the system. Hence, a set of stretched coordinates is considered to derive the modified KdV equation. It is found that the presence of nonthermality of ions does not only significantly modify the basic properties of solitary structure, but also changes the polarity of the solitary profiles. In the vicinity of the critical hot dusty plasma density, neither KdV nor mKdV equation is appropriate for describing the DAWs. Therefore, a further modified KdV (fmKdV) equation is derived, which admits both soliton and double layer solutions. A theoretical investigation for the energy of two temperatures charged dusty grains were computed. It is found that, the grains energy are very sensitive to the plasma parameters. In the presence of kinematic viscosity, The KdV-Burgers equation is derived. It is found that solitary and shock (oscillatory and monotonic) waves can be produced in this medium. The effects of important parameters such as hot and cold dust charge and density parameters on the properties of shock waves are discussed. The present investigation can be of relevance to the electrostatic solitary structures observed in various space plasma environments such as Saturn F-ring’s. |