A Centre Manifold Description of Contaminant Dispersion in Channels with Varying Flow Properties

Autor:	A. J. Roberts, G. N. Mercer
Rok vydání:	1990
Předmět:	Physics::Fluid Dynamics Diffusion equation Advection Turbulence Applied Mathematics Mathematical analysis Fluid dynamics Shaping Thermal diffusivity Hagen–Poiseuille equation Open-channel flow Mathematics
Zdroj:	SIAM Journal on Applied Mathematics. 50:1547-1565
ISSN:	1095-712X 0036-1399
DOI:	10.1137/0150091
Popis:	High-order asymptotic approximations to the equation governing the longitudinal dispersion of a passive contaminant in Poiseuille channel flow are derived, and their validity discussed. The derivation uses centre manifold theory, which provides a systematic and near rigorous approach to calculating each successive approximation. It also enables the derivation of the correct initial conditions for the Taylor model of shear dispersion. Approximations that are valid when the channel is of a varying cross section are systematically derived via this approach, and the effects of time-dependent flow and variable diffusivity are also investigated. The resultant modifications to the effective advection velocity and the effective dispersion coefficient are calculated and some general trends indicated.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::b9b3c76ea15e7593d0b246a553099d50 https://doi.org/10.1137/0150091 Zobrazit plný text záznamu