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Nonlinear flows in nearly incompressible hydrodynamic fluids
1Institute of Geophysics and Planetary Physics, University of California, Riverside, California 92521, USA.
Summary
Nonlinear fluid simulations reveal that acoustic and fluid modes in nearly incompressible fluids drive instabilities. Reynolds stress forces generate saturated flows, dissipating long wavelengths through resonant conditions.
Area of Science:
- Fluid Dynamics
- Nonlinear Systems
- Acoustic Phenomena
Background:
- Nearly incompressible viscous hydrodynamic fluids exhibit complex behaviors.
- Acoustic modes arise from high-frequency fluctuations in subsonic flows.
- These modes interact with fluid modes, leading to instabilities.
Purpose of the Study:
- To investigate the dynamics of nearly incompressible viscous hydrodynamic fluids.
- To understand the role of acoustic and fluid modes in flow excitation.
- To analyze the generation and dissipation mechanisms of nonlinear flows.
Main Methods:
- Nonlinear fluid simulations were employed.
- Analysis focused on acoustic and fluid modes interactions.
- Comparison with analytic predictions was performed.
Main Results:
- Acoustic and fluid modes were found to drive linearly unstable modes.
- Nonlinear flows were excited and subsequently damped long wavelengths.
- Resonant dissipation occurred under specific nonlinear conditions.
Conclusions:
- Nonlinear flows in nearly incompressible fluids are generated by Reynolds stress forces.
- Simulation results align with analytic predictions.
- Understanding these dynamics is crucial for predicting fluid behavior.