In this paper, the problem of linear stability of viscous liquid films down an inclined plane is solved by finite difference method. It is applicable for moderate values of Reynolds and wave numbers. The obtained results by this method is compared with ones of some papers and with experimental data.

SurviMARY. The Hopf bifurcation of plane Poiseuille flows is studied numerically. On the base of the rigorous theory worked out by Joseph and Sattinger [1], a detailed effective and simple algorithm for numerical determination of the type of the above mentioned bifurcation is proposed. The obtained result shows that the bifurcation at the lower branch of the linear stability neutral curve is supercritical meantime at the upper branch the one is subscritical.