32 research outputs found
Computational Study of the Dynamics of the Flow-Field Induced by Vortex Generators
No full textVortex Generators (VGs) are one of the most commonly used passive flow control devices. Recent studies have shown that it is beneficial to use sub-boundary layer vortex generators (SBVGs). The height of these generators varies between 10% - 50% of the boundary layer thickness. However, the reduced height causes the induced vortices to be substantially weaker. Therefore, using SBVG is beneficial only when the regions of flow separation are well defined. To better understand and comprehensively predict the effectiveness of these devices for flow control over a range of operating conditions, two different SBVG profile: rectangular vortex generators (RVGs) and triangular vortex generators (TVGs) are analysed when subjected to a laminar boundary layer. The topics of interest are instantaneous flow, mean flow, far-field acoustic properties and influence of the angle of attack on the VG vane. The results emphasise the unsteady nature of the induced vortices for both the VG profiles. For RVGs, mean flow visualisation indicates the presence of local re-circulation zones in between the vanes with an increase in angle of attack. Additionally, secondary vortices are noted for both the VGs. These secondary vortices significantly influence the properties of the primary vortices thereby, suggesting that, effectively managing the secondary vortices using suitable design changes to VG profile could be one of the possible ways to accomplish better flow control.Aerospace Engineerin
Fruit peel waste as a novel low-cost bio adsorbent
No full textFruit peel waste (FPW) is abundantly available from the agricultural and food processing industry and has been studied in recent past as an adsorbent. This paper critically reviews the reported work and investigates various FPW-pollutant systems. The study includes statistics of FPW generation, modification, characterization, adsorption ability, recovery/regeneration, and modeling (isotherms, kinetics, and thermodynamics) of batch adsorption. It is found that orange and banana peels are the most extensively studied adsorbents, whereas Pb2+ and methylene blue are the most efficiently removed pollutants, the Langmuir and Freundlich adsorption isotherms provide the best fit in most of the cases, and in general, pseudo-second-order kinetics is followed. There are very limited column studies and no report on commercial plant. Though the reproducibility of the results is poor, FPW has a great potential in the wastewater treatment due to its abundant and cheap availability. FPW can be used for removal of heavy metals and dyes; however, removal of organic and gaseous impurities needs further investigation
Performance analysis of dual-hop optical wireless communication systems over k-distribution turbulence channel with pointing error
No full textUtilization of banana peel for the removal of benzoic and salicylic acid from aqueous solutions and its potential reuse
No full textWe report on the adsorptive removal of benzoic acid (BA) and salicylic acid (SA) using banana peel (BP), an abundantly available agricultural waste material, for the first time. BP was characterized by proximate analysis, FT-IR, scanning electron microscopy, BET surface area, and XRF. The number of basic sites on BP (4.9 mmol g−1) is relatively more than acidic sites (0.75 mmol g−1). The Langmuir uptake capacity values obtained are 6.62 mg g−1 for BA and 9.80 mg g−1 for SA. A mechanism for binding acid molecule to the BP surface is proposed
Fruit peel waste: characterization and its potential uses
No full textGlobally, India is the leading producer of fruits. Fruits after consumption leave a peel which is a nuisance to the environment as a solid waste. In this article, commonly available large volume-fruit peels (FP) (viz. banana, orange, citrus, lemon and jackfruit) were investigated for surface, physical and chemical characteristic with a view to propose their valorization in detail. Each FP was characterized by proximate and ultimate analysis, porosity, particle density, bulk density, point of zero charge (pHpac), surface pH, surface charges, water absorption capacity, BET surface area, scanning electron microscopy, Fourier transform infrared spectroscopy and TGA/derivative of thermogravimetric. The BET surface area of FP is very less, between 0.60 and 1.2 m2/g. The pHpac and surface pH values of orange peel (OP), citrus peel (CP), lemon peel (LP) and jackfruit peels (JFP) are in the range of 3-4. The pHpac value and surface pH of banana peel (BP) is closer to 7. The order of surface acidity is OP > LP > CP > JFP > BP. From TG curves it is clear that FPs are stable below 150°C. The results will be useful for rational design, when FP is used as a substrate for bioactive compounds, phenolic antioxidants, organic acids, enzymes, biofertilizer, production of energy and as absorbents
