ABSTRACT
The closed system of linearized equations of fluid dynamics (2.8)-(2.12) allows us, in principle, to describe the propagation of sound waves in moving media. But this system is rather complicated and hence, it is inconvenient for solving particular problems. On the other hand, for arbitrary ambient quantities P, e, V.L, Sand Ci , this system of equations cannot be reduced rigorously to a single equation which would be more simple for analysis than the starting system. Scientists have been trying to reduce it to a single equation, by using various approximations or assumptions about a moving medium, during the whole period of the study of sound propagation in moving media.
