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Friction factor evaluation in tidal rivers and estuaries
Evgeniya Panchenko1,2, Andrei Alabyan1,2
1Lomonosov Moscow State University, Moscow, Russia.
Methodsx
|April 11, 2022
Summary
This study introduces a new method to analyze friction factors in tidal rivers, crucial for improving hydrodynamic models. Accurately measuring friction variations enhances simulations of unsteady flow in estuaries and tidal rivers.
Area of Science:
- Hydraulics and Fluid Dynamics
- Environmental Engineering
- Coastal Engineering
Background:
- The Saint-Venant equations are fundamental for simulating unsteady flow in hydraulic environments like tidal rivers and estuaries.
- Tidal rivers exhibit high variability in hydraulic resistance due to changing forces (gravity, inertia, friction) during a tidal cycle.
- Current hydrodynamic models often use uniform flow resistance parameters for unsteady currents, potentially limiting accuracy.
Purpose of the Study:
- To develop and present a novel method for measuring, calculating, and analyzing friction factor variations in tidal rivers and estuaries.
- To evaluate the contribution of different forces to water movement within the Saint-Venant momentum equation during a tidal cycle.
- To improve the accuracy of one-dimensional hydrodynamic models for tidal river systems.
Main Methods:
- Development of a method to measure and calculate the friction factor in tidal rivers with reverse flow.
- Analysis of the range and variation of the friction factor throughout a tidal cycle.
- Evaluation of the contribution of each term in the Saint-Venant momentum equation.
Main Results:
- The proposed method enables the identification of the range for each term in the Saint-Venant momentum equation.
- It allows for the quantitative evaluation of forces driving water movement during tidal cycles.
- Experimental determination of the friction factor's variation is demonstrated as critical for accurate modeling.
Conclusions:
- Accurate hydrodynamic modeling of tidal rivers necessitates experimental evaluation of the friction factor and its variations.
- The developed method provides key insights into the dynamics of unsteady flow in tidal environments.
- Understanding friction factor variability is essential for reliable simulation of tidal estuaries and rivers.
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