Modified Eddy Viscosity Model in Fully Developed Asymmetric Channel Flows

• Published in: Journal of engineering mechanics 1994-04, Vol.120 (4), p.720-732
• Main Authors: Tsai, Whey-Fone, Ettema, Robert
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fundamental areas of phenomenology (including applications); Physics; TECHNICAL PAPERS; Turbulence simulation and modeling; Turbulent flows, convection, and heat transfer
• ISSN: 0733-9399; 1943-7889
• DOI: 10.1061/(ASCE)0733-9399(1994)120:4(720)

This study presents a modified eddy viscosity model for describing vertical distribution of turbulent eddy viscosity in one-dimensional fully developed asymmetric channel flows, which cannot be obtained by the traditional eddy viscosity model. A two-power law expression, used to describe vertical distribution of flow velocity, is shown to account quite well for the major characteristics of flow in channels of asymmetric roughness. The modified eddy viscosity model, utilizing the two-power law expression, enables formulation of a continuous distribution of eddy viscosity with positive magnitudes of turbulent eddy viscosity for asymmetric channel flows. Examples are given showing that the distribution of eddy viscosity obtained by using the modified eddy viscosity model is comparable with that obtained using Launder and Spalding's k‐ε turbulence model. This modified eddy viscosity model can, therefore, provide a relatively simple means for estimation of turbulent eddy viscosity in asymmetric channel flows.