WAVE PROCESSES IN PIPELINES
Considered waveguide properties of the pipeline for liquid or gaseous media. The geometrical parameters of pipelines, the parameters of the environments their fill, working wavelengths determine the number of modes of waves can propagate. The movement of the medium filling the pipeline, leads to the non-reciprocity of wave parameters of all modes propagating in the duct in the forward and backward directions. The formulas for the calculation of wave numbers of forward and backward waves of different modes, formulas of the critical wavelengths depending on the speed of the media. Defined angles that apply partial waves in direct and opposite directions. It is established that the velocity of the medium is affected by the parameters of forward and backward waves, the number of modes of acoustic waves propagating in the pipe in forward and backward directions.