We give an asymptotic equivalent at infinity of the unbounded solutions of some boundary layer equations arising in fluid mechanics. Let us consider the following boundary layer differential equation f ′′′ + ff ′′ − βf ′2 = 0 (1) where β < 0. We are interested in non constant solutions (that we will simply call solutions) of (1) defined on some interval [t0,∞) and such that f (∞) := lim t→∞ f (...

Our concern is with the evolution of large amplitude Tollmien-Schlichting waves in boundary layer ows. In fact the disturbances we consider are of a comparable size to the unperturbed state. We shall describe two-dimensional disturbances which are locally periodic in time and space. This is achieved using a phase equation approach of the type discussed by Howard and Kopell (1977) in the context...

The foundational differences of steady and unsteady jets issued into a laminar boundary layer crossflow are considered. Jets have been used widely for flow control applications, due to their ability enhance mixing mitigate separation, but it is unclear what role jet steadiness plays in effectiveness. Here we compare experimentally (synthetic) rectangular flat-plate with varying orifice pitch sk...

In the present paper, a numerical method has been demonstrated which works on an overall NewtonRaphson type algorithm and is capable of solving the “inverse” problem for turbulent, fullydeveloped, pulsating pipe flows, where the mass flow rate, rather than the pressure gradient is prescribed as a periodic function of time. The momentum equation, governing the transient, fullydeveloped pulsating...