| Abstract: | A study is made of the propagation in channels of forced oscillations generated by harmonic variation of the boundary conditions at the entrance and exit sections. Linear theory is used to find classes of boundary conditions and frequencies of the forced oscillations corresponding to the greatest gain or attenuation of high-frequency oscillations in a channel of variable section and of oscillations of arbitrary frequency in a channel of constant section. The resonance phenomenon that arises in channels when the frequencies of the forced oscillations and the fundamental oscillations are equal is studied. The wave process in a channel of variable section is investigated numerically, its characteristics found, and a comparison made with the linear theory. It is shown that the results of the calculations and the data of the linear analysis agree well.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 127–135, September–October, 1980.We thank A. B. Vatazhin for helpful discussions. |
