Аннотация:http://icders2017.com/wp-content/uploads/26th_ICDERS_Program/Oral/26th%20ICDERS_submission_769.pdf
Annular and dual slotted linear nozzles with the internal deflector are considered as perspective for realization a pulsing, including the detonation regime of fuels combustion [1]. The study of pressure pulsation signals are topical to determination the dependence the spectral composition of pulsations from geometric nozzles parameters and the flow conditions in them in order to govern by frequency of a process. Also of interest is clarification the degree of influence of gas pressure pulsations in the flow on the thrust characteristics of these nozzles. The paper presents the results of computational and experimental study of dependences of frequency and oscillations amplitude of flow parameters in annular and dual slotted linear nozzles from the conditions at the inlet and the outlet of the nozzle and its geometry. Experiments with annular nozzles were conducted in a pulsed aerodynamic setup using as the working gas the combustion products of acetylene-air mixture. Calculations were made on the basis of the Navier-Stokes equations for multicomponent reactive gaseous medium using a single-temperature chemical nonequilibrium model including all main products of the combustion of a stoichiometric mixture of acetylene in air. As a result of investigation the dependences frequencies and oscillations amplitudes of the flow parameters in annular and equivalent gas flow dual slotted linear nozzles from the governing parameters were established. We dealt with different pressures at the inlet and exit of nozzles, different sizes of the critical cross-section and different diameters of the annular nozzle. Presented the comparison results of computational and measured spectral composition of quasi-periodic pulsating signal of pressure on the thrust wall of the annular nozzle obtained by the discrete Fourier transform on the time interval 0.5 to 2.5 ms. The calculation predicted the existence of quasi-periodic pulsating regimes of gas flow in a dual slotted linear nozzle and defined the spectral composition of pressure pulsations on the thrust wall and the thrust force developed by the such nozzle.