Showing papers by "S.V. Prabhu published in 2018"
TL;DR: In this paper, a theoretical study is introduced to predict the hydrodynamic performance of a vertical axis Savonius turbine with semicircular vanes, based on the concept of stagnation pressure rise at the turbine vanes and Newton's second law of impulse momentum principle.
33 citations
TL;DR: In this article, the mass burning rate, puffing frequency, flame height, optical thickness, spatial distribution of emissivity and temperature, irradiance and fire safety distance were determined for pool fires.
27 citations
TL;DR: In this article, a single head full cone simplex nozzle with X-type swirl-insert and an orifice diameter of 1.2mm is used to produce water mist.
26 citations
TL;DR: In this paper, the authors compared the wall temperature and heat transfer coefficient distribution on the inner side and the outer side of helical coils at different diameter ratios and density ratios, and concluded that the circumferential wall temperature variation in a helical coil decreases with increase in a diameter ratio and with decrease in a density ratio.
24 citations
TL;DR: In this paper, the heat transfer characteristics of a single flame jet impinging on convex and concave surfaces of a semi-cylindrical target plate are investigated, and the uniformity of the heat flux distribution and the overall thermal efficiency are determined from the local heat flux distributions.
15 citations
TL;DR: The influence of Reynolds number and blockage ratio on the vortex dynamics of a trapezoidal bluff body placed inside a circular pipe is studied experimentally and numerically in this article, where four different flow regimes are defined based on the distinct features of Strouhal number (St)-ReD relation: steady, laminar irregular, transition and turbulent.
Abstract: The influence of Reynolds number and blockage ratio on the vortex dynamics of a trapezoidal bluff body placed inside a circular pipe is studied experimentally and numerically. Low aspect ratio, high blockage ratio, curved end conditions (junction of pipe and bluff body), axisymmetric upstream flow with shear and turbulence are some of the intrinsic features of this class of bluff body flows which have been scarcely addressed in the literature. A large range (200:200,000) of Reynolds number (ReD) is covered in this study, encompassing all the three pipe flow regimes (laminar, transition and turbulent). Four different flow regimes are defined based on the distinct features of Strouhal number (St)–ReD relation: steady, laminar irregular, transition and turbulent. The wake in the steady regime is stationary with no oscillations in the shear layer. The laminar regime is termed as irregular owing to irregular vortex shedding. The vortex shedding in this regime is observed to be symmetric. The emergence ...
13 citations
TL;DR: In this paper, the influence of curvature on local heat transfer coefficient, two-phase pressure drop and CHF in helical coils is investigated. But, very little information is available on the effect of curvatures on flow boiling system.
11 citations
TL;DR: In this paper, a single phase heat transfer in a partially-filled, rotating horizontal pipe with axial liquid (water) flow is studied and thermal imaging is used to capture outer wall temperature of the partially filled rotating heated pipe.
10 citations
TL;DR: In this paper, the authors investigated the behavior of overall heat transfer coefficient with randomized packing of uniformly sized spheres inside the concentric tube heat exchangers at the laboratory scale and found that the reduction in length in comparison to heat exchanger without packing is ∼95%.
8 citations
TL;DR: In this paper, a minimization technique that makes use of the Nelder-Mead algorithm is developed to solve for the over-determined system of equations, which is capable of separating the convective and radiative heat transfer components from impinging diffusion flames.
8 citations
TL;DR: In this article, the exact nature of diffusion of heat in the plate is investigated via solution to multidimensional heat conduction problem, and two procedures have been employed: Duhamel theorem and three dimensional transient analytical IHCP.
TL;DR: In this paper, the effect of different spray parameters such as nozzle geometry, spray mass flow rate, and Sauter mean diameter on vessel pressure and temperature is measured, and experiments are carried out in a vessel of 500'mm diameter and 1200'mm height.
TL;DR: In this paper, the authors studied the two-phase pressure drop in helical coils and suggested that the influence of a helical coil is completely included in the single phase pressure drop correlation for helical coarsens.
Abstract: The objective of the present work is to study the two-phase pressure drop in helical coils. Literature on the two-phase pressure drop in a helical coil suggests the complexity in flow boiling inside a helical coil due to secondary flow. Most of correlations reported in the literature on the two-phase pressure drop in a helical coil are limited to a specific operating range. No general correlation is available for a helical coil which is applicable for all fluids. In the present study, an experimental databank collected containing a total of 832 data points includes the data from the present study and from the literature. The data includes diabatic pressure drop of two fluids namely water and R123. Data covers a range of parameters namely a mass flux of 120–2058 kg/m2 s, a heat flux of 18–2831 kW/m2, an exit quality of 0.03–1, a density ratio of 32–1404 and a coil to tube diameter ratio of 14–58. The databank is compared with eighteen empirical correlations which include well referred correlations of straight tubes and the available correlations of helical coils. The straight tube correlations are not working well for the present data set. The helical coil correlations work reasonably well for the present databank. A correlation is suggested to predict the two-phase pressure drop in helical coils. The present study suggests that the influence of a helical coil is completely included in the single phase pressure drop correlation for helical coils.
TL;DR: In this article, a partially-filled, rotating inclined pipe with water flowing through it is experimentally investigated and a generalised correlation to predict the average Nusselt number is developed in terms of four dimensionless numbers.
TL;DR: In this paper, the authors reported the heat transfer characteristics of convex shaped surface burners with 49 inline ports arranged in an array of 7 each and impinged the pre-characterised air jets of various flow rates on the rear surface and captured the wall temperature.