Abstract
A three-dimensional hydrodynamic model has been applied to study the Mach cones in a three-dimensional complex plasma. Numerical results for the velocity distribution of dust particles showed the presence of compressional-wave Mach cones. The compressional Mach cones were excited when subjected to supersonic excitations. It was found that multi-cone structures became a single cone when the discharge pressure was increased. The experiment of Mach cones in a three-dimensional complex plasma under microgravity conditions on board the International Space Station was also reported. A single compressional-wave Mach cone in a three-dimensional complex plasma was observed and could also be obtained from our hydrodynamic model.