Asymptotic behavior of the unbounded solutions to some degenerate boundary layer equations revisited

摘要

We reconsider the boundary-layer flow of a non-Newtonian fluid corresponding to the classical Ostwald de Waele power-law model. The physical problem can be described in terms of solutions of the degenerate differential equation (vertical bar f ''vertical bar(n-1) f '')' + ff '' - beta f'(2) = 0, posed on the interval (0,infinity), in which beta < 0 and the real number (the power law index) n >= 1. This paper deals with the asymptotic behavior of any global unbounded solution; that is a solution satisfying lim(eta ->infinity) vertical bar f(n)vertical bar = infinity.