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Fluctuation-induced force in homogeneous isotropic turbulence.
Vamsi Spandan1, Daniel Putt2, Rodolfo Ostilla-Mónico2
1Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
Science Advances
|April 15, 2020
Summary
We discovered a novel fluctuation-induced force between plates in turbulent fluids. This force, dependent on plate distance and fluid dynamics, offers new insights into Casimir forces in nonequilibrium systems.
Area of Science:
- Statistical Physics
- Fluid Dynamics
- Nonequilibrium Systems
Background:
- Understanding force generation in nonequilibrium systems is a significant challenge.
- Fluctuation-induced forces are crucial in statistical physics.
- Turbulence involves complex energy and vorticity distributions.
Purpose of the Study:
- To investigate the fluctuation-induced force between two plates in homogeneous isotropic turbulence.
- To elucidate the mechanism behind this force generation.
- To explore the relationship between fluid structures and Casimir forces.
Main Methods:
- Direct numerical simulations of fluid turbulence.
- Analysis of pressure variations between plates at different separations.
- Examination of energy and vorticity structures within the turbulent flow.
Main Results:
- A nonmonotonic fluctuation-induced force was observed between the plates.
- The force's behavior is linked to the exclusion and interaction of energy and vorticity structures.
- A complex dependence on the Reynolds number was identified.
Conclusions:
- Length scale-dependent distributions of energy and vortex structures dictate Casimir forces.
- The interaction of intense vorticity structures (worms) significantly influences the force.
- This study provides a new perspective on forces in turbulent nonequilibrium systems.
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