The phenomenon of pressure drop and the heat transfer for single-phase microelectronic pin fin heat sinks has been analyzed numerically for many varying pin fin shapes. The present study is based on cooling the pin fins by forced air convection using ANSYS Fluent software. The primary intents of this study focus on maximum heat transfer and minimum flow resistance in pin fins. The aerodynamic efficiency of fins with varying shapes is analyzed to obtain the best-optimized shape for pin fins of heat sinks. The staggered rounded leading edges pin fin has a better quality factor (QF) with low pumping power and the pressure drop for the inlet flow velocities are higher than 4 m/s. Conic sections of pin fins with staggered configurations have been observed to provide better aerodynamic efficiency for Reynolds number ranging 450–900 whereas rounded leading edge of pin fin of heat sinks provides better aerodynamics efficiency for Reynolds numbers above 900.

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A numerical study has been carried out on the two-dimensional flow past a circular cylinder. In this case, a splitter plate is provided at the rear stagnation point in the downstream direction. ansys fluent has been used to carry out the numerical simulations based on finite volume method approach. Grid independence was achieved and the numerical model was validated with results available in open literature at Reynolds numbers of 100, 5000, and 100,000 respectively. In the present investigation, the characteristics of vortex shedding due to the presence of splitter plate in the circular cylinder were investigated. The main focus of this research was to find the optimal splitter plate length for low, moderate, and high Reynolds numbers. It was observed that at low, moderate, and high Reynolds numbers, the drag coefficient (cd) for optimal plate length decreased drastically as compared to the baseline circular cylinder case. Moreover, the fluctuating nature of lift coefficient (cl) had also ceased. This research work has a good potential to decrease time-varying structural loads on bluff bodies by decreasing the vortex shedding frequency and consequently decreasing drag. The scope of our research extends to structures of bridges and large vehicles, radiator pipes of heat exchangers, landing gears of aircraft, and many more.@en

Rayleigh Taylor instability has been investigated numerically and experimentally by many researchers for more than a century for studying various properties. The unstable interface between the two fluids of varying density with the fluid of higher density being superposed over the fluid with lower density has been studied using various experiments and numerical models. In the recent decades the analysis was more focused on internal conditions, properties and turbulence as the experiments could be designed with more precision and advanced technologies. Lot of research has been done at varying Atwood number which is ratio of difference in the densities of fluids to the sum of fluid densities. This phenomenon happens on the surface of an expanding bubble deep-water, in nuclear explosion, astrophysics. In this review, authors have discussed the understanding of the instability and research done by some of the researchers and also have discussed some of topics which could be investigated further.

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Finite volume method for solving the Navier stokes equation is employed for studying 2D incompressible flow around an array of three cylinders placed in a staggered arrangement at two Reynolds numbers 100 and 200. Numerical simulations have been performed for the configurations having three cylinders of equal diameter for varying the longitudinal and transverse gaps. The transverse gap is varied in the first case (T = 0.75D, 1.5D, and 3D) to study the effects on the wake of the cylinders. The second analysis has been performed for the configurations having three cylinders of unequal diameters (D = 0.5D and 1.5D) by varying the diameter of the cylinders in staggered arrangement. The coefficient of forces has been analyzed for this configuration and compared with the results of the simulation of isolated cylinder. The authors have tried to understand the flow behavior in the simulation from the vorticity contours and the streamlines. The complex flow pattern due to mutual interaction between the wakes of the cylinders has been studied based on the varying transverse and the longitudinal distance.

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