A mixing length model for estimating channel conveyance

Autor:	Nigel Wright, Matthew S. Horritt
Rok vydání:	2013
Předmět:	Numerical analysis Mathematical analysis Prandtl number Boundary (topology) Fluid mechanics Manning formula Open-channel flow symbols.namesake Mixing length model symbols Statistical physics Mixing (physics) Water Science and Technology Mathematics
Zdroj:	Proceedings of the Institution of Civil Engineers - Water Management. 166:165-174
ISSN:	1751-7729 1741-7589
DOI:	10.1680/wama.11.00066
Popis:	This paper describes a simple, physically based mixing length model that explains the functional form of Manning's equation for mean velocity in open channels. Manning's equation has been used to describe mean velocity for over 100 years and is essentially an empirical result rather than being based on an understanding of physical processes. The model described in this paper uses Prandtl's mixing length hypothesis, with mixing length modelled at each point within the cross-section being proportional to the distance to the nearest solid boundary. The model solves equations for the along-stream velocity field using a simple numerical method on regular and irregular finite-difference meshes. The results of the model are compared with Manning's equation and the Colebrook–White formula, giving good agreement across a range of channel sizes, roughnesses and geometries. The results and comparison are used to draw useful insights into open channel flows.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::930b576ee98e0bcaf16a99167dc41324 https://doi.org/10.1680/wama.11.00066 Zobrazit plný text záznamu