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Turbulent viscosity variability in self-preserving far wake with zero net momentum
Katya Dubrovin1, Ephim Golbraikh, Michael Gedalin
1Physics Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 21, 2011
Summary
This study enhances the turbulent viscosity model for self-preserving far wakes. A new model accounts for radius-dependent viscosity, yielding a broader range of self-similar wake profiles.
Area of Science:
- Fluid Dynamics
- Turbulence Modeling
Background:
- Far wake profiles are crucial in fluid dynamics.
- Current models assume uniform turbulent viscosity, limiting predictive accuracy.
- Observed wake widths deviate from predictions (W∝z(α), α≤1/5).
Purpose of the Study:
- To generalize the self-preserving far wake model.
- To incorporate a radius-dependent turbulent viscosity coefficient.
- To derive new self-similar wake profiles.
Main Methods:
- Developed a generalized turbulent viscosity model.
- Introduced additional integrals of motion.
- Analyzed self-similar wake profiles.
Main Results:
- The generalized model accommodates radius-dependent turbulent viscosity.
- New self-similar profiles were derived, matching observed wake width dependencies (α≤1/5).
- The model's predictions align better with experimental observations.
Conclusions:
- The assumption of uniform turbulent viscosity is a limitation.
- Radius-dependent viscosity is essential for accurate far wake modeling.
- The new model provides a more comprehensive understanding of turbulent wakes.
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