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Retarding viscous Rayleigh-Taylor mixing by an optimized additional mode
1CAPT-HEDPS, IFSA Collaborative Innovation Center of MoE, SKLTCS, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China.
Physical Review. E
|March 17, 2017
Summary
Numerical simulations show that adding an optimized mode to random interface disturbances can significantly slow down Rayleigh-Taylor (RT) mixing in viscous fluids. This finding may apply to diffusion processes like concentration and thermal diffusion.
Area of Science:
- Fluid Dynamics
- Computational Physics
Background:
- Rayleigh-Taylor (RT) mixing occurs at the interface of accelerated fluids with different densities.
- Random interface disturbances typically enhance mixing, leading to complex interfacial structures.
Purpose of the Study:
- To investigate the effect of superimposed modes on RT mixing dynamics.
- To identify an optimized mode that can suppress RT mixing.
Main Methods:
- Numerical simulation of incompressible viscous fluid mixing.
- Analysis of ensemble-averaged spike velocity under modified interface conditions.
Main Results:
- Superimposing an optimized mode significantly retards the ensemble-averaged spike velocity.
- The optimal mode's wavenumber balances suppression of long-wavelength modes with sufficient velocity for effective density-gradient layer growth.
Conclusions:
- An optimized suppressing mode can effectively control RT mixing.
- This principle may extend to RT mixing phenomena involving diffusion processes like concentration and thermal diffusion.
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