An experimental and numerical study was carried out to investigate the heat transfer by natural convection in a three dimensional annulus enclosure filled with porous media (silica sand) between two inclined concentric cylinders with (and without) annular fins attached to the inner cylinder under steady state condition. The experiments were carried out for a range of modified Rayleigh number (0.2 ≤Ra*≤ 11) and extended to Ra*=500 for numerical study and for annulus inclination angle of (δ = 0˚, 30˚, 60˚ and 90˚). The numerical study was to give the governing equation under assumptions that used Darcy law and Boussinesq’s approximation and then it was solved numerically using finite difference approximation. It was found that the average Nusselt number depends on (Ra*, Hf, δ and Rr ). The results showed that the increasing of the fin length increases the heat transfer rate for any fin pitch unless the area of the inner cylinder exceeds that of the outer one; then the heat will be stored in the porous media. A comparison was made between the results of the present work and those of other researches for the case without fins and excellent agreement was obtained.
Hydrocarbon displacement at the pore scale is mainly controlled by the wetness properties of the porous media. Consequently, several techniques including nanofluid flooding were implemented to manipulate the wetting behavior of the pore space in oil reservoirs. This study thus focuses on monitoring the displacement of oil from artificial glass porous media, as a representative for sandstone reservoirs, before and after nanofluid flooding. Experiments were conducted at various temperatures (25 – 50° C), nanoparticles concentrations (0.001 – 0.05 wt% SiO2 NPs), salinity (0.1 – 2 wt% NaCl), and flooding time. Images were taken via a high-resolution microscopic camera and analyzed to investigate the displacement of the oil
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The present paper concerns with peristaltic analysis of MHD viscous fluid in a two dimensional channel with variable viscosity through a porous medium under the effect of slip condition. Along wave length and low Reynolds number assumption is used in the problem formulation. An analytic solution is presented for the case of hydrodynamic fluid while for magneto hydrodynamic fluid a series solution is obtained in the small power of viscosity parameter. The salient features of pumping and trapping phenomena are discussed in detail through a numerical integration. The features of the flow characteristics are analyzed by plotting graphs and discussed in detail. When .
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The influence of anodization time with the electrochemical cell design on the fabrication process of porous silicon (PS) nanostructures based on two electrochemical anodization cells (designed single tank cell and double tank cell) with two anodization times (10 and 30 minutes) was studied. Atomic force Microscopy (AFM) characterization had revealed three types of pores, mesopores, mesopore fill of mesopores, and macropore fill of mesopores were obtained from designed single tank cell with (10 and 30 minutes) of anodization time, whilst for double tank cell has not revealed precise information about the size and type of pores. Pores formation have been further approved by current-voltage (I-V) measurement and pho
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In this research for each positive integer integer and is accompanied by connecting that number with the number of Bashz Attabq result any two functions midwives to derive a positive integer so that there is a point
The inner wasteland can be observed in Samuel Beckett’s early and later plays. His characters suffer from loss of identity, emotions, and sense of time. They lead a life of failure, repetition, inaction, loneliness, doubt, suffering, and nothingness. The inner wasteland includes many aspects, such as the multi and split identity, the habitual repetitive element of life, the dark sorrowful life the characters lead, lack of communication and relations among them, their unfree, inactive condition, their foggy terrible recollections, loneliness, dryness of love, and uncertainty. The analysis and the illustration of each aspect will show how the inner wasteland is intensified in the selected later plays of Beckett.
The heat transfer and flow resistance characteristics for air flow cross over circular finned tube heat exchanger has been studied numerically and experimentally. The purpose of the study was to improve the heat transfer characteristics of an annular finned-tube heat exchanger for better performance. The study has concentrated on the effect of the number of perforations and perforations shapes on the heat transfer and pressure drop across a staggered finned tube heat exchanger. The Numerical part of present study has been performed using ANSYS Fluent 14.5 using SST Turbulent model, while the experimental study consist from a test rig with different models of heat exchangers and all required measurement devices were build
... Show MoreDue to the potential cost saving and minimal temperature stratification, the energy storage based on phase-change materials (PCMs) can be a reliable approach for decoupling energy demand from immediate supply availability. However, due to their high heat resistance, these materials necessitate the introduction of enhancing additives, such as expanded surfaces and fins, to enable their deployment in more widespread thermal and energy storage applications. This study reports on how circular fins with staggered distribution and variable orientations can be employed for addressing the low thermal response rates in a PCM (Paraffin RT-35) triple-tube heat exchanger consisting of two heat-transfer fluids flow in opposites directions throug
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