Experimental research on characteristic of turbulent kinetic energy at the interface between compressible mixing layer and free stream

Using PIV (particle image velocimetry) and schliren technique, the characteristic of interface, specially growth rate of turbulent kinetic energy, between free stream and compressible mixing layer at convective Mach number Mc =0.38 has been investigated. The results show that the increase or decrease of turbulent kinetic energy mainly derivates from the compressibility of fluid particle near the interface. The work resulting from streamwise linear strain of averaged velocity plays an important role of turbulent kinetic energy near the interface. It seems that the existence of largescale structure suppresses the change of turbulent kinetic energy near the interface.