Non-linear Topographic Effects in Two-Layer Flows

Frontiers in Digital Humanities

Baines, Peter G.¹  Johnson, Edward R.² 

[1] Department of Infrastructure Engineering, The University of Melbourne, Melbourne, VIC, Australia;Department of Mathematics, University College London, London, UK

关键词: 2-layer flow;    Non-Boussinesq;    topography;    Froude number;    hydraulic jump;   

DOI  :  10.3389/feart.2016.00009

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

We consider the nature of non-linear flow of a two-layer fluid with a rigid lid over a long obstacle, such that the flow may be assumed to be hydrostatic. Such flows can generate hydraulic jumps upstream, and the model uses a new model of internal hydraulic jumps, which results in corrections to flows that have been computed using earlier models of jumps that are now known to be incorrect. The model covers the whole range of ratios of the densities of the two fluids, and is not restricted to the Boussinesq limit. The results are presented in terms of flow types in various regions of a Froude number-obstacle height (F0 – Hm) diagram, in which the Froude number F0 is based on the initial flow conditions. When compared with single-layer flow, and some previous results with two layers, some surprising and novel patterns emerge on these diagrams. Specifically, in parts of the diagram where the flow may be supercritical (F0 > 1), there are regions where hysteresis may occur, implying that the flow may have two and sometimes three multiple flow states for the same conditions (i.e. values of F0 and Hm).

【 授权许可】

CC BY