Talk · Journal of Physics Conference Series · November 1, 2017

The electron beam diagnostic of the clustered supersonic nitrogen jets

Svetlana V. Avtaeva, T. S. Yakovleva, V. V. Kalyada, A. Е. Зарвин

Abstract

Axial and radial distributions of the rotational temperature and density of N 2 molecules in supersonic nitrogen jets formed with conic nozzles (critical diameters d cr of 0.17 and 0.21 mm) were studied using the electron beam fluorescence technique at stagnation pressures P 0 of 0.1-0.6 MPa. A rotational temperature T r , equaling a gas temperature T g owing to fast RT relaxation, was obtained using the rotational line relative intensity distribution in (0-1) vibrational band of the N 2 first negative system. Gas density profiles in the jets were obtained using the integral intensity of the band. It is found, T r at the nozzle outlet is of the order of a few tens of Kelvin and at further expansion T r drops up to 15-20K at distance of (100-200) d cr . The gas temperature and density distributions in the studied supersonic nitrogen jets are not similar to the isentropic distributions. It is shown that the lower is the stagnation pressure the faster the gas density and temperature decrease with distance from the nozzle. Increase in P 0 leads to elevating T g in the jets. A reason for this effect may be cluster formation in the jets. Estimations of cluster mean sizes in the jets using Hagena's parameter show presence of large clusters (M≥200) at P 0 = 0.4-0.6 MPa.

Gas Dynamics and Kinetic TheoryLow-Pressure Plasma Processing and DiagnosticsMolecular Spectroscopy and Structuregas clustersrotational temperaturegas density profile

The electron beam diagnostic of the clustered supersonic nitrogen jets

Abstract

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