Marneni Narahari

Bio: Marneni Narahari is an academic researcher from Universiti Teknologi Petronas. The author has contributed to research in topics: Nusselt number & Nanofluid. The author has an hindex of 14, co-authored 45 publications receiving 655 citations. Previous affiliations of Marneni Narahari include Petronas.

Hall effects on MHD flow in a rotating system with heat transfer characteristics

Abstract: Closed-form solutions are derived for the steady magnetohydrodynamic (MHD) viscous flow in a parallel plate channel system with perfectly conducting walls in a rotating frame of reference, in the presence of Hall currents, heat transfer and a transverse uniform magnetic field A mathematical analysis is described to evaluate the velocity, induced magnetic field and mass flow rate distributions, for a wide range of the governing parameters Asymptotic behavior of the solution is analyzed for large M 2 (Hartmann number squared) and K 2 (rotation parameter) The heat transfer aspect is considered also with Joule and viscous heating effects present Boundary layers arise close to the channel walls for large K 2, ie strong rotation of the channel For slowly rotating systems (small K 2), Hall current parameter (m) reduces primary mass flow rate (Q x /R ρ v) Heat transfer rate at the upper plate (d θ/d η) η=1 decreases, while at the lower plate (d θ/d η) η=−1 increases, with increase in either K 2 or m For constant values of the rotation parameter, K 2, heat transfer rate at both plates exhibits an oscillatory pattern with an increase in Hall current parameter, m The response of the primary and secondary velocity components and also the primary and secondary induced magnetic field components to the control parameters is also studied graphically Applications of the study arise in rotating MHD induction machine energy generators, planetary and solar plasma fluid dynamics systems, magnetic field control of materials processing systems, hybrid magnetic propulsion systems for space travel etc

A review on preparation methods, stability and applications of hybrid nanofluids

Abstract: Hybrid nanofluid is a new class of nanofluids engineered by dispersing two different nanoparticles into conventional heat transfer fluid. Hybrid nanofluids are potential fluids that offer better heat transfer performance and thermo-physical properties than convectional heat transfer fluids (oil, water and ethylene glycol) and nanofluids with single nanoparticles. Scientific findings have indicated that hybrid nanofluid can replace single nanofluid since it provides more heat transfer enhancement especially in the areas of automobile, electro-mechanical, manufacturing process, HVAC and solar energy. In this paper, we summarized the recent progress related to preparation methods of hybrid nanofluids, factors affecting their stability, methods of enhancing thermal properties and current applications of hybrid nanofluids. Finally, some challenging issues that need to be solved for future research are discussed.