Application of Nano Technique in Measuring Supersonic/Hypersonic Flow

ABSTRACT Turbulence, universally exist in nature and human activities, is a kind of three-dimensional, irregular, unsteady flow. Ever since 19 th century when people started to investigated turbulent flow technically, they have never dropped the potent and intuitionistic experimental method. Recently, with the development of aviation and aerospace industry， especially with the increase desire of supersonic and hypersonic flight, the mechanism of high speed and compressible flow has become hot topic of fluid research, resulting in development of measurement method and technique. When encountering compressible high flow, traditional techniques, such as schilieren, shadow and interference, cannot measure fine flow structures. Fortunately, multiple-discipline integration of nano technique, laser technique and imaging technique provides a new design for fluid measurement。Nano-tracer planar laser scattering (NPLS) is a new flow visualization technique, which was developed by the authors' group in 2005, and it can visualize time correctional flow structure in a cross-section of instantaneous 3D supersonic flow at high spatiotemporal resolution. Many studies have demonstrated that NPLS is a powerful tool to study supersonic turbulence