基于相干反斯托克斯拉曼散射的等离子体流场热力学非平衡特性表征方法研究OA

Temperature is considered to be one of the most concerned parameters to quantitatively describe flow characteristics,of which the measurement accuracy directly affects the prediction of aerodynamic,aerothermal and thermal protection performance of hypersonic vehicles.Based on the principles of Coherent Anti-Stokes Raman Scattering(CARS),a CARS spectral computation and vib-rotational temperature inversion program is proposed for characterizing the thermodynamic non-equilibrium properties of the high-temperature gas flow field.And corresponding accuracy from 1 000 K to 2 300 K is verified in a static environment.A non-equilibrium microwave plasma flow is built and its vibrational temperature and rotational temperature with different pressures,N2 volumetric flow rate,and compositions are obtained by using the developed program.The results show that within the range of experimental conditions,with pressure increasing,the vibrational temperature and rotational temperature decrease,while the thermodynamic non-equilibrium degree increases but corresponding increase rate decreases.With N2 volumetric flow rate increasing,the vibrational temperature and rotational temperature first increase and then decrease,while the thermodynamic non-equilibrium degree exhibits an opposite trend.With Ar volume fraction increasing,the vibrational temperature first increases and then decreases,and the rotational temperature increases,while the thermodynamic non-equilibrium degree decreases.