ИСТИНА

Numerical and experimental study of spectrum signals of pressure pulsations on thrust wall in the annular and dual slotted linear nozzles were performed. For the basic configuration of the annular nozzle was experimentally established the main dominant spectrum frequency (22 kHz), qualitatively confirmed by calculations (30 kHz). The numerical research of dependence of frequency and oscillation amplitude of flow parameters in these nozzles showed that the management of the main dominant frequency can most effectively be carried out as due to of a proportional increase in nozzle scale (frequency decreases proportionally), and the size of critical section and height of the deflector, regardless of flight altitude – backpressure in the space of outflow. Usage these adjustments helped to demonstrate the variation ability the main dominant pressure pulsation in the studied nozzles in the range of 7 to 30 kHz. In calculations first were predicted the existence quasi-periodic pulsating regimes of laminar gas flow in dual slotted linear nozzles and was established the dominant pulsation frequency (≈ 25 kHz) of pressure on the nozzle thrust wall.