
| Dr. Surapati Pramanik | |
| Affiliation | Assistant Professor, Department of mathematics,Nandalal Ghosh B.T. College,Panpur, Narayanpur,India. |
| Email-Id: | sura_pati@yahoo.co.in |
Publication: Books:
Publications:
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| Dr. Surapati Pramanik | |
| Affiliation | Assistant Professor, Department of mathematics,Nandalal Ghosh B.T. College,Panpur, Narayanpur,India. |
| Email-Id: | sura_pati@yahoo.co.in |
Publication: Books:
Publications:
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Authors: Avinash M, Manjunath S.H, Vikram C.K
Abstract: The turbulent flow past square cylinders is a fundamental problem in fluid mechanics because it governs aerodynamic loading, vortex-induced vibration, drag, and heat transfer in engineering systems such as high-rise buildings, bridge piers, offshore structures, heat exchangers, and electronic cooling devices. Despite extensive research, accurately predicting flow separation, wake development, and thermal transport under varying operating conditions remains challenging. This review critically synthesizes recent advances in both experimental and numerical investigations of turbulent flow past square cylinders. Experimental techniques, including Particle Image Velocimetry, Laser Doppler Velocimetry, hot-wire anemometry, pressure measurements, and flow visualization, are assessed alongside Computational Fluid Dynamics approaches based on Reynolds-Averaged Navier–Stokes, Large Eddy Simulation, Detached Eddy Simulation, Scale-Adaptive Simulation, and Direct Numerical Simulation. The influence of Reynolds number, blockage ratio, corner modifications, thermal boundary conditions, and multiple-cylinder arrangements on wake dynamics and heat transfer is systematically evaluated. The review shows that Large Eddy Simulation provides the most accurate prediction of vortex shedding, wake structures, and aerodynamic forces, whereas Reynolds-Averaged Navier–Stokes models remain computationally efficient for engineering applications. Corner rounding, chamfering, and passive flow-control techniques consistently reduce drag and suppress wake instability while improving thermal performance. Remaining challenges include high-Reynolds-number simulations, coupled thermo-fluid analysis, turbulence model accuracy, and systematic experimental validation. The review identifies current research gaps and highlights future opportunities in advanced turbulence modelling, high-performance computing, and data-driven approaches to support the design of safer, more efficient, and thermally optimized bluff-body engineering systems.
Authors: Dr. G. Sugendran, Surinder Kumar
Abstract: The continuing shrinking trend of electronics along with growing power densities has resulted in many heat dissipation difficulties. Microchannel heat sinks are promising and compact heat sinks but limited by thermal performance due to thermal capabilities of traditional coolant fluids. This work examines the prospect of using hybrid nanofluids, i.e., a mixture of several different nanoparticles, to improve the convective heat transfer coefficients of microchannel flow. A detailed numerical analysis based on the two-phase Eulerian-Eulerian approach is performed to assess the thermohydrodynamic properties of aluminum oxide-copper/water hybrid nanofluid through rectangular microchannels under Reynolds numbers between 200 and 1000 and nanoparticle volume fractions between 0.5% and 2.0%. The simulations reveal a considerable heat transfer enhancement where the Nusselt number rises up to 38.4% at 1.0% volume fraction while reducing the thermal resistance by 29.6% and achieving the highest thermal efficiency ratio of 1.31. Although there is an increased pressure drop (18.7%), the thermal-hydraulic performance proves the feasibility of hybrid nanofluids as a new coolant.