Boundary shear stress and apparent shear forces in compound channels with different floodplain widths

ABSTRACT

The present study has studied a model to predict depth-averaged velocity distribution and boundary shear stress in compound channels with different floodplain widths. The model was verified against three different data sets of the present experiments and two data used in the literature. The results indicate that the present model can predict the depth-averaged velocity and shear stress distributions, promising to simulate the flow field and related characteristics better. The results show that the non-dimensional coefficient plays a dominant role in portraying the variation of depth-averaged velocity and shear stress distributions in compound channels with different floodplain widths. In addition, the apparent shear forces were examined by dividing the channel cross-section into seven parts, and each element carried shear forces and acted on the horizontal and vertical interfaces for three different width-to-depth ratios were discussed and analyzed. In all configurations, the horizontal interface was negative, indicating that the upper region of flow accelerates the flow in the lower main channel. In contrast, the vertical interfaces were positive, suggesting that the slower floodplain flows retards the faster main channel flows.

KEYWORDS:

• Compound channels
• boundary shear stress
• apparent shear forces
• floodplain width
• depth-averaged velocity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Some or all data, models, or codes that support the findings of this study are available from the corresponding author upon reasonable request.

Author contributions

Ebissa Gadissa Kedir: Conceptualization, Data collection, Writing the first draft, Design, Editing, Formal Analysis and Validation; C. S. P. Ojha: Analysis, Review and Editing; K. S. Hari Prasad: Review and Editing.