Magnetohydrodynamic Effect on Thermal Transport by Silver Nanofluid Flow in Enclosure with Central and Lower Heat Sources

Abstract

A numerical investigation into the magneto-convection heat transfer performance of Ag-based nanofluid (i.e., silver nanoparticles dispersed in fluid) filled square enclosure containing a thin central heater and a lower heated wall section is performed. The analysis focuses particularly on the effects of the magnetic field strength, central heater orientation and length, lower heated wall section length, Rayleigh number, and Ag nanoparticle volume fraction on the average Nusselt number along the cool, vertical sidewalls of the enclosure. It is found that the heat transfer performance improves as the lengths of the central heater and lower heated wall section increase. Also, the average Nusselt number increases given a vertical orientation of the central heater. Regardless of the heater orientation, the heat transfer performance decreases with increasing magnetic field strength. As Ag nanoparticle volume fraction increases, the average Nusselt number increases with increasing values of Rayleigh number. Finally, the heat transfer performance improves for increasing nanoparticle volume fraction (0.00, 0.03, 0.06, 0.09) at high Rayleigh numbers of 10⁶ and 10⁷.

Acknowledgments

The authors gratefully acknowledge the financial support provided to this study by the Ministry of Science and Technology of Taiwan under Project Nos. MOST-107-2221-E-006-126-MY3 and MOST-108-2811-E-006-506. The authors are grateful to Dr. S. Kogularasu, Postdoctoral Research Faculty, Department of Photonics, NCKU, Taiwan, for the provision of the TEM images of the nanofluid.

Additional information

Notes on contributors

Mahalakshmi Thangavelu

Mahalakshmi Thangavelu received her Ph.D. in computational fluid dynamics from Bharathiar University, India. She was a Post-Doctoral Research Fellow in the Department of Engineering Science at National Cheng Kung University, Taiwan. Her research work concerns numerical analysis of heat transfer enhancement in enclosures with heat sources utilizing nanofluids.

Nithyadevi Nagarajan

Nithyadevi Nagarajan is an Assistant Professor in the Department of Applied Mathematics, Bharathiar University, India. She received her Ph.D. in computational fluid dynamics from Bharathiar University, India and Post-Doctoral Research Fellowship in National Cheng Kung University, Taiwan. She specializes in analyzing convective heat transfer inside enclosures with obstructions.

Ruey-Jen Yang

Ruey-Jen Yang is a Chair Professor at National Cheng Kung University, Tainan, Taiwan. He received the Ph.D. degree from the University of California at Berkeley, USA in 1982. He is the recipient of three outstanding scholar awards from the Ministry of Science and Technology (MOST) in Taiwan. He is a fellow of ASME and research fellow of MOST. His research activities include thermal/fluid sciences, micro-/nano-fluidics, energy conversion, and computational physics.