ИСТИНА

One-dimensional axial movement of tensioned viscous material jet or fiber (no mass forces are taken into account) is considered. Applying the laws of a mass and motion quantity conservation it is shown, that the stationary flow is characterized by exponential decrease of jet width and corresponding increase of jet velocity. The problem of stability behavior of a moving viscous material is studied taking into account the axial stresses and also the representation of defining model variables as the sum of stationary distributions and small perturbations is used. Equations for perturbations of state variables are derived, which depend on the defining parameter (the inverse to the Reynolds number) characterizing the combined influence of viscosity, density, initial velocity and length of the considered interval. For small parameter values, a dynamic stability of one-dimensional material motion is established.