Steady and Unsteady Dynamics of Magneto-Nanofluidic Flow in a Bottom-Heated Top-Cooled Recto-Triangular Thermal System

Abstract

This work numerically explores the evolution flow features during the journey through unsteady to steady dynamics in a magneto-nanofluidic thermal system of recto-triangular shape. This system, which is partially heated using the triangular surface and employs a top-cooling configuration, features an upper rectangular and a lower triangular part. The study addresses laminar flow for various Rayleigh numbers (Ra) up to 10⁵ considering uniform magnetic fields at different inclination angles and utilizing a 0.1% nanoparticle concentration (fixed) CuO-water nanofluid along with a finite element-based solver. The results reveal the formation of multi-vortical structures with varying numbers of circulation cells. The most important observation is the transformation of cells from a four-cell configuration to a one-cell configuration, and finally to a two-cell configuration as Ra changes from 10³ to 10⁴ to 10⁵ without a magnetic field. The one-cell structure sustains over a narrow range of Ra and is sensitive to the Hartmann number (Ha). The inclined magnetic fields have a severe impact on the flow structure. Starting from a quiescent state and progressing through the unsteady flow stages, the system rapidly reaches a steady state under different temperature differences (simulated by Ra), except for a few exceptions of Ra and Ha values. The analysis of the unsteady stages of flow development provides deeper insights into the dynamics of multi-cellular flows.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Nirmal K. Manna

Nirmal K. Manna completed his Ph.D. (Mechanical Engineering) from Jadavpur University in 2005, and his master’s degree in Heat Power from Bengal Engineering Deemed University (presently known as Indian Institute of Engineering Science and Technology) in 1996. He has 4 years of industrial experience and has been working as a professor in the Mechanical Engineering Department of Jadavpur University in India since 2007. His research interests are the development of CFD code on single and multiphase flows, bio-fluid mechanics, free and forced convection, spool valves of HCS, FCI, and premixing. He has published several of research papers in international journals and conference proceedings.

Nirmalendu Biswas

Nirmalendu Biswas graduated from Jadavpur University and did a master’s in mechanical engineering from Jadavpur University. He received his Ph.D. in Engineering from Jadavpur University, Kolkata in 2016. He has more than ten years of industrial experience. Presently he is an Assistant Professor in the Department of Power Engineering, Jadavpur University, Kolkata, India since 2019. His research interests include heat transfer, microfluidics, multiphase flow, energy storage, phase-change material, and bio-fluid mechanics. He has published a several research papers in international journals and conference proceedings. He is an INAE fellow recipient. He is a life member of the ISHMT, FMFP, and IEI.

Dipak Kumar Mandal

Dipak Kumar Mandal graduated in Mechanical Engineering from the Institution of Engineers, in 1997. He received his master’s degree from the IIEST, Shibpur, in 1999. He completed his Ph.D. from the same university in 2010. His research areas are CFD, heat transfer, porous media, and bio-fluid mechanics. He has written two books, Fluid Mechanics and Hydraulic Machines, published by Vikash Publishing House, and Power Plant Engineering: Theory and Practice by Wiley India. He has worked in the thermal power plant for 12 years. Presently, he is working as an Associate Professor at Department of Mechanical Engineering, Government Engineering College, Samastipur, Bihar 848127, India. He has published several research papers in international journals and conference proceedings. He is a life member of the IEI.

Chandan Kumar Yadav

Chandan Kumar Yadav completed his master’s (fluid mechanics & hydraulics engineering) from Jadavpur University in 2022, bachelor’s (Mechanical Engineering) in 2013, has 2 years of industrial experience, and presently pursuing Ph.D. in the Aerospace Engineering Department of IIT Kanpur in India since 2022. His research interests are free and mixed MHD convection, nano-fluids, CFD, and turbomachinery. He has published a few research papers in international conference proceedings.