метод Галеркина.

Optical systems with two-dimensional feedback demonstrate wide possibilities for emergence of dissipative structures. Feedback allows to influence on dynamics of the optical system by controlling the transformation of spatial variables performed by prisms, lenses, dynamic holograms and other devices.

The Galerkin method together with the method of small parameter is applied for study of Routh­like equations describing the dynamics of two­dimensional inviscid incom­pressible fluid flows. A set of simple models for some vortical flows of such fluid in rectangular area has been derived and analysed.