Coronal mass ejections are the main results of powerful solar activity. These activities are capable of generating shock waves in the interplanetary medium. The shock waves happen when the solar particles change their velocities from supersonic to subsonic. Since the interaction of shock waves with viscosity is one of the central problems in the supersonic regime of compressible gas flow, investigations of these events play a crucial role in space weather research . The main purpose of this study is to study the effects of viscosity on the shock waves observed after the CMEs of 20/11/2003 and CME11/04/2010.