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Motion of a density current head in a diverging channel
H Torabi Poudeh1, M Fathi-Moghadam, M Ghomesi
1School of Water Sciences Engineering, Shahid Chamran University, Ahvaz, Iran.
Journal of Environmental Science & Engineering
|February 6, 2009
Summary
Density current head velocity increases with channel divergence and bed slope. Beyond 12 degrees of divergence, the velocity increase is minimal, with a new model predicting these effects.
Area of Science:
- Environmental fluid dynamics
- Sediment transport dynamics
- River engineering
Background:
- Density currents form when rivers meet reservoirs, influencing sediment distribution.
- Understanding density current head velocity is crucial for reservoir management and sediment control.
Purpose of the Study:
- To experimentally investigate the impact of channel divergence on density current head velocity.
- To develop a predictive model for density current head velocity in diverging channels.
Main Methods:
- Experiments were conducted in a laboratory flume with varying channel slopes and divergence angles.
- Head velocity was measured for different discharges and compared between uniform and diverging channels.
- Dimensional analysis and experimental data were used to formulate a mathematical model.
Main Results:
- Density current head velocity was higher in diverging channels than in uniform channels.
- Head velocity increased with the degree of channel divergence up to 12 degrees.
- Increased bed slope led to higher head velocities, consistent with prior research.
Conclusions:
- Channel divergence significantly influences density current head velocity, with diminishing returns beyond 12 degrees.
- The developed mathematical model can predict head velocity across various slopes and divergence angles.
- Findings aid in managing sediment transport and deposition in reservoir environments.
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