Complex results in experimental and numerical flow dynamics research and spectra signals of gas pressure pulsations in annular and linear dual-slotted nozzles are presented. Experiments are performed in a pulsed aerodynamic setup using acetylene-air mixture combustion products as working gas. Viscous flow calculations are based on the Navier-Stokes equations for multicomponent reactive gaseous medium using single-temperature chemical nonequilibrium model. As a result, the frequency Fourier spectrum of pressure pulsation at the thrust wall center is determined. Typical pulsed pressure signals obtained in the calculations and detected in the experiments are presented.