Seminar
Title: |
EHD of a bubble rise |
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Speaker: |
Prof. S. Vengadesan |
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Affiliation: |
IIT Madras |
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When: |
Thursday, November 21, 2024 at 11:00:00 AM |
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Where: |
MRDC Building, Room 4211 |
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Host: |
Alexander Alexeev | |
Abstract The bubble-rising phenomenon is crucial in diverse industries such as petroleum, pharmaceuticals, polymers, chemical processing, and wastewater treatment. Manipulating bubble behavior, notably through externally applied electric fields, holds significant promise for various applications. The present study focuses on establishing a foundational understanding of bubble rising under the influence of an electric field. To conduct simulations, we developed an in-house electrohydrodynamic solver integrated with an open-source finite volume method (FVM) within the OpenFOAM framework. The solver is meticulously validated against the literature and found to be robust in calculating electrical force and capturing interface in the presence of the electric field. In this talk, I will explain the phenomena of bubble rise due to the effect of electric capillary number (CaE)â , electrical conductivity ratio (R), and permittivity ratio (S). The electrical force comprises dielectrophoretic force (DEF) and Coulomb force, which increases with higher values of CaE, R, and S. As the bubble begins to ascend in the presence of an electric field, the tangential component of the electrical force induces vortices in the vicinity of the bubble, which interact with the bubble's motion. These interactions result in various phenomena: the ascent of undeformed and deformed bubbles, the ascent of wall-attached bubbles, bubble ascent with path instability, and bubble breakup. In the absence of an electric field, a small spherical bubble exhibits various shapes, including ellipsoidal, ellipsoidal cap, bi-oblate, dimpled ellipsoidal, or retains its original spherical form. |
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Biography Professor Vengadesan has been working with Department of Applied Mechanics and Biomedical Engineering, IIT Madras, Chennai, India for the last 21 years. He specializes in CFD, Multiphase Flow and Unsteady Aerodynamics. He has supervised so far 11 PhD and 31 MS, and currently supervising 9 PhD and 6 MS. He has published 97 journal articles and equal number of conference presentation. Details are available in https://home.iitm.ac.in/vengades/ |
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