Velocity history measurement of hypersonic tunnel driver based on photon Doppler velocimeter

The research of hypersonic process is limited by the transition model, turbulence and computational complexity. At present tunnel test still a better way to investigate than fluid dynamic (CFD) method. In this work, principle structure all-fiber photon Doppler velocimeter (PDV) are introduced. PDV based on laser effect consists an Mach Zehnder interferometer optical antenna. measurement accuracy distance tested, showing that error can be controlled within 0.17 m/s when velocity piston below 40 m/s. same time, measured reach 26.3 m. continuous free using in high enthalpy expansion China aerodynamics development center (CARDC). During tests, placed next tunnel, antenna installed behind observation window connected circulator fiber. When driving pressure 1.3 MPa, maximum numerical simulation 88.981 m/s, 88.810 with relative deviation –0.19%; 2.7 125.100 123.843 –1.00%. reaches before impacting then decelerates rapidly under joint action compression wave. Therefore, soft landing proves feasible, which put forward Stallkerin 1960s. Finally, reasons why missed impact discussed. Through analysis received intensity, it believed absorption, scattering beam caused strong main reason.