Title: Role of aspiration to enhance MHD convection in protruded heater cavity

Authors: Nirmalendu Biswas; Nirmal K. Manna; Aparesh Datta; Dipak Kumar Mandal; Ali Cemal Benim

Addresses: Department of Power Engineering, Jadavpur University, Salt Lake, Kolkata, 700106, India ' Department of Mechanical Engineering, Jadavpur University, Kolkata, 700032, India ' Department of Mechanical Engineering, NIT Durgapur, West Bengal, 713209, India ' Department of Mechanical Engineering, College of Engineering and Management, Kolaghat, 721171, India ' Faculty of Mechanical and Process Engineering, Duesseldorf University of Applied Sciences, Germany

Abstract: The implementation of aspiration (without fans/pumps) of the working medium can significantly intensify heat transfer in low power magneto-hydrodynamic (MHD) thermal applications. To explore its effectiveness over no-aspiration condition, a classical thermal cavity with protruded-heater (centrally mounted at bottom) is considered along with magnetic fields. The aspiration openings are provided at the bottom of the sidewalls (for passive partial suction) and in the middle of the top wall (for partial venting). For different strengths of magnetic fields and buoyancy, and heater sizes, the simulations are performed using an in-house code for a range of Rayleigh number (Ra), Hartmann number (Ha), and heater aspect ratio (A). The evolved results indicate substantial augmentation of heat transfer (up to 46%) from free aspiration. The imposed magnetic field prominently controls temperature and convective-flow fields. The aspiration plays a positive role in heat transfer enhancement under natural convection with and without a magnetic field.

Keywords: magneto-hydrodynamic flow; magneto-hydrodynamic; MHD; aspiration; natural convection; protruded heater; heat transfer augmentation.

DOI: 10.1504/PCFD.2020.111408

Progress in Computational Fluid Dynamics, An International Journal, 2020 Vol.20 No.6, pp.363 - 378

Received: 10 Sep 2019
Accepted: 17 Jun 2020

Published online: 20 Oct 2020 *

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