The triple-deck stage of marginal separation.

Unlabelled: The method of matched asymptotic expansions is applied to the investigation of transitional separation bubbles. The problem-specific Reynolds number is assumed to be large and acts as the primary perturbation parameter. Four subsequent stages can be identified as playing key roles in the characterization of the incipient laminar-turbulent transition process: due to the action of an adverse pressure gradient, a classical laminar boundary layer is forced to separate marginally (I).

Linear and nonlinear propagation of higher order modes in hard-walled circular ducts containing a real gas.

This paper deals with the linear and nonlinear propagation of sound waves through a real gas contained in a circular tube with rigid, isothermal walls. Special emphasis is placed on the asymptotically correct treatment of the higher order modes and their interaction with the acoustic boundary layer. In the first part, a linear perturbation analysis is carried out to calculate the correction terms arising from the viscothermal damping mechanisms present in the system.

On the calculation of the transmission line parameters for long tubes using the method of multiple scales.

The present paper deals with the classical problem of linear sound propagation in tubes with isothermal walls. The perturbation technique of the method of multiple scales in combination with matched asymptotic expansions is applied to derive the first-order solutions and, in addition, the second-order solutions representing the correction due to boundary layer attenuation. The propagation length is assumed to be so large that in order to obtain asymptotic solutions which extend over the whole spatial range the first-order corrections to the classical attenuation rates of the different modes come into play as well.