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Anais da Academia Brasileira de Ciências

Print version ISSN 0001-3765

Abstract

MIKHAILOV, MIKHAIL D.  and  FREIRE, ATILA P. SILVA. Feasible domain of Walker's unsteady wall-layer model for the velocity profile in turbulent flows. An. Acad. Bras. Ciênc. [online]. 2014, vol.86, n.4, pp.2121-2136. ISSN 0001-3765.  http://dx.doi.org/10.1590/0001-3765201420130528.

The present work studies, in detail, the unsteady wall-layer model of Walker et al. (1989, AIAA J., 27, 140 – 149) for the velocity profile in turbulent flows. Two new terms are included in the transcendental non-linear system of equations that is used to determine the three main model parameters. The mathematical and physical feasible domains of the model are determined as a function of the non-dimensional pressure gradient parameter (p+). An explicit parameterization is presented for the average period between bursts (), the origin of time () and the integration constant of the time dependent equation (A0) in terms of p+. In the present procedure, all working systems of differential equations are transformed, resulting in a very fast computational procedure that can be used to develop real-time flow simulators.

Keywords : law of the wall; turbulent boundary layer; unsteady model; feasible domain; asymptotic theory.

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