Oscillatory instability of Rayleigh-Marangoni-Bénard convection in two-layer liquid system
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Q.S. Liu
Abstract
The oscillatory behaviour of the Rayleigh–Marangoni–Bénard convective instability (R-M-B instability) regarding two combinations of two-layer fluid systems has been investigated theoretically and numerically. For the two-layer system of Silicone oil (10cSt) over Fluorinert (FC70), both linear instability analysis and 2D numerical simulation show that the instability of the system depends strongly on the depth ratio Hr = H1/H2 of the two-layer liquid. The oscillatory regime at the onset of R-M-B convection enlarges with reducing Γ = Ra /Ma values. In the two-layer system of Silicone oil (2cSt) over water, it loses its stability and onsets to steady convection at first, then the steady convection bifurcates to oscillatory convection with increasing Rayleigh number Ra. This behaviour was found through numerical simulation above the onset of steady convection in the case of Γ = 2.9, ε = (Ra − Rac ) / Rac = 1.0, and Hr = 0.5. Our findings are different from the previous study of the Rayleigh–Bénard instability and show the strong effects of the thermocapillary force at the interface on the time-dependent oscillations at or after the onset of convection. We propose a secondary oscillatory instability mechanism to explain the experimental observation of Degen et al. [Phys. Rev. E, 57 (1998), 6647–6659].
Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- Editorial
- Linear Marangoni and Rayleigh-Taylor instabilities of a ferrofluid thick layer in a vertical magnetic field
- Free surface shear flows induced by Marangoni and alternating electromagnetic forces
- Instability of two-phase mixing layers: analysis of exact and approximate base flows from boundary layer theory
- Thermocapillarity-induced vortexes and liquid film dynamics on structured heated walls
- Numerical strategies for the simulation of dissolution kinetics and fluid-dynamic instabilities in liquid couples with a miscibility gap
- A study of heat transfer in liquid bridges near onset of instability
- Experimental and numerical study of the Marangoni convection due to localized laser heating
- Oscillatory instability of Rayleigh-Marangoni-Bénard convection in two-layer liquid system
Articles in the same Issue
- Editorial
- Linear Marangoni and Rayleigh-Taylor instabilities of a ferrofluid thick layer in a vertical magnetic field
- Free surface shear flows induced by Marangoni and alternating electromagnetic forces
- Instability of two-phase mixing layers: analysis of exact and approximate base flows from boundary layer theory
- Thermocapillarity-induced vortexes and liquid film dynamics on structured heated walls
- Numerical strategies for the simulation of dissolution kinetics and fluid-dynamic instabilities in liquid couples with a miscibility gap
- A study of heat transfer in liquid bridges near onset of instability
- Experimental and numerical study of the Marangoni convection due to localized laser heating
- Oscillatory instability of Rayleigh-Marangoni-Bénard convection in two-layer liquid system
