Charge injection in horizontal eccentric annuli filled with a dielectric liquid

• Published in: European journal of mechanics, B, Fluids Vol. 72; pp. 691 - 700
• Main Authors: Hassen, Walid, Elkhazen, Mohamed Issam, Traore, Philippe, Borjini, Mohamed Naceur
• Format: Journal Article
• Language: English
• Published: Elsevier Masson SAS 01.11.2018; Elsevier
• Subjects: Acoustics; Automatic; Biomechanics; Chemical Sciences; Computational fluid mechanics; Dielectric liquid; Eccentric annular space; Electric power; Electro-convection; Electro-hydro-dynamic (EHD); Electromagnetism; Engineering Sciences; Fluid mechanics; Material chemistry; Materials and structures in mechanics; Mathematical Physics; Mechanics; Multicellular flow; Numerical simulation; Physics; Polymers; Quantum Physics; Reactive fluid environment; Thermics; Vibrations; Computational fluid mechanics; Eccentric annular space; Numerical simulation; Multicellular flow; Electro-hydro-dynamic (EHD); Electro-convection; Dielectric liquid; Dielectric liquids
• ISSN: 0997-7546; 1873-7390
• DOI: 10.1016/j.euromechflu.2018.08.009

In this paper, we carry out a numerical study of the Coulomb-driven electro-convection flow in a dielectric liquid using the finite volume method (FVM). The system under study consists of an eccentric annulus layer subjected to strong unipolar injection from an inner cylinder. All equations are written in bi-cylindrical coordinate system and are expressed using the vorticity–stream function method. The behavior of the fluid for different system parameters is well studied. The taken parameters are in the range of eccentricity 0 ≤ e ≤ 80%, injection strength in the range of 0.5 ≤ C ≤ 10 and electric Rayleigh number in the range of 30 ≤ T ≤ 1600. The distributions of the electric charge density and stream function are carefully examined. The computations highlight a significant effect of the eccentricity value on the flow topography. Indeed, increasing the eccentricity value leads to a significant reduction in electro-plumes as well as circulation cells number. Furthermore, an intensification in cells rotation, of about 116%, was recorded when eccentricity reaches 80%. Depending on torque values e-T, we observe the existence of multicellular regime made of counter-rotating vortexes.