Numerical Study of the Dynamics of Non-Newtonian Carreau Droplets under Electrowetting Phenomenon

Document Type : Research Article

Authors

1 Mechanical Engineering, Sharif Institute University, Tehran, Iran Emission Expert, Megamotor Co., Tehran, Iran

2 Department of Mechanical Engineering-Sharif University of Technology

Abstract

Studying the dynamic behavior of droplets is very important in electrowetting phenomena. Due to the widespread application of non-Newtonian fluids, in the present study, the dynamics of non-Newtonian Carreau droplets have been investigated. The effects of the viscosity, the size and the applied voltage on the oscillations and the change in the height of the droplets have been inspected. The simulations have been conducted using the finite element method and in order to validate the method, the results have been compared with the available experimental and numerical results. The results indicate that by increasing the viscosity the amplitude of the oscillations increases but the frequency remains constant. These are similar to those of the Newtonian fluids with this difference that in Newtonian fluids the amplitude is larger but the frequency is smaller. Also, for Carreau fluids when the power index is smaller than one the results are similar to the Newtonian fluids but when the power index is larger than one the droplet reaches its final height faster and without any fluctuation. Increasing the height in the non-Newtonian fluid leads to an increase in the amplitude of the oscillations and decreases the amount of frequency in the fluid.

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References

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Amirkabir Journal of Mechanical Engineering
Volume 53, Issue 1 (Special Issue)
April 2021
Pages 319-338

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