Search results for: perforated metal
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2528

Search results for: perforated metal

2528 Air Flows along Perforated Metal Plates with the Heat Transfer

Authors: Karel Frana, Sylvio Simon

Abstract:

The objective of the paper is a numerical study of heat transfer between perforated metal plates and the surrounding air flows. Different perforation structures can nowadays be found in various industrial products. Besides improving the mechanical properties, the perforations can intensify the heat transfer as well. The heat transfer coefficient depends on a wide range of parameters such as type of perforation, size, shape, flow properties of the surrounding air etc. The paper was focused on three different perforation structures which have been investigated from the point of the view of the production in the previous studies. To determine the heat coefficients and the Nusselt numbers, the numerical simulation approach was adopted. The calculations were performed using the OpenFOAM software. The three-dimensional, unstable, turbulent and incompressible air flow around the perforated surface metal plate was considered.

Keywords: perforations, convective heat transfers, turbulent flows, numerical simulations

Procedia PDF Downloads 580
2527 A Numerical Study on the Flow in a Pipe with Perforated Plates

Authors: Myeong Hee Jeong, Man Young Kim

Abstract:

The use of perforated plate and tubes is common in applications such as vehicle exhaust silencers, attenuators in air moving ducts and duct linings in jet engines. Also, perforated plate flow conditioners designed to improve flow distribution upstream of an orifice plate flow meter typically have 50–60% free area but these generally employ a non-uniform distribution of holes of several sizes to encourage the formation of a fully developed pipe flow velocity distribution. In this study, therefore, numerical investigations on the flow characteristics with the various perforated plates have been performed and then compared to the case without a perforated plate. Three different models are adopted such as a flat perforated plate, a convex perforated plate in the direction of the inlet, and a convex perforated plate in the direction of the outlet. Simulation results show that the pressure drop with and without perforated plates are similar each other. However, it can be found that that the different shaped perforated plates influence the velocity contour, flow uniformity index, and location of the fully developed fluid flow. These results can be used as a practical guide to the best design of pipe with the perforated plate.

Keywords: perforated plate, flow uniformity, pipe turbulent flow, CFD (Computational Fluid Dynamics)

Procedia PDF Downloads 691
2526 Multi-Factor Optimization Method through Machine Learning in Building Envelope Design: Focusing on Perforated Metal Façade

Authors: Jinwooung Kim, Jae-Hwan Jung, Seong-Jun Kim, Sung-Ah Kim

Abstract:

Because the building envelope has a significant impact on the operation and maintenance stage of the building, designing the facade considering the performance can improve the performance of the building and lower the maintenance cost of the building. In general, however, optimizing two or more performance factors confronts the limits of time and computational tools. The optimization phase typically repeats infinitely until a series of processes that generate alternatives and analyze the generated alternatives achieve the desired performance. In particular, as complex geometry or precision increases, computational resources and time are prohibitive to find the required performance, so an optimization methodology is needed to deal with this. Instead of directly analyzing all the alternatives in the optimization process, applying experimental techniques (heuristic method) learned through experimentation and experience can reduce resource waste. This study proposes and verifies a method to optimize the double envelope of a building composed of a perforated panel using machine learning to the design geometry and quantitative performance. The proposed method is to achieve the required performance with fewer resources by supplementing the existing method which cannot calculate the complex shape of the perforated panel.

Keywords: building envelope, machine learning, perforated metal, multi-factor optimization, façade

Procedia PDF Downloads 224
2525 Development and Evaluation of Removable Shear Link with Perforated Web

Authors: Daniel Y. Abebe, Jaehyouk Choi

Abstract:

The objective of this paper is to investigate, through an analytical study, the behavior of both stiffened and un-stiffened removable shear link with perforated web considering different number and size of web openings. Removable shear link with perforated web is a novel shear link beam proposed to be used in eccentrically braced frame (EBF). The proposed link overcomes the difficulties during construction slab due to less cross-sectional areas of the link to control the plastic deformation on the conventional EBF with removable shear link. Finite element analyses were conducted under both cyclic and monotonic loading and from the results obtained design equations are developed.

Keywords: eccentrically braced frame, removable shear link, perforated web, non-linear FE analysis

Procedia PDF Downloads 363
2524 Comparison of ANN and Finite Element Model for the Prediction of Ultimate Load of Thin-Walled Steel Perforated Sections in Compression

Authors: Zhi-Jun Lu, Qi Lu, Meng Wu, Qian Xiang, Jun Gu

Abstract:

The analysis of perforated steel members is a 3D problem in nature, therefore the traditional analytical expressions for the ultimate load of thin-walled steel sections cannot be used for the perforated steel member design. In this study, finite element method (FEM) and artificial neural network (ANN) were used to simulate the process of stub column tests based on specific codes. Results show that compared with those of the FEM model, the ultimate load predictions obtained from ANN technique were much closer to those obtained from the physical experiments. The ANN model for the solving the hard problem of complex steel perforated sections is very promising.

Keywords: artificial neural network (ANN), finite element method (FEM), perforated sections, thin-walled Steel, ultimate load

Procedia PDF Downloads 352
2523 Flexural Test of Diversing Foam Core Sandwich Composites

Authors: Santhana Krishnan R, Preetha C

Abstract:

Sandwich construction with strong and stiffness facing and light weight cores is increasingly cores being used in structures where the predominant loads are flexural. The objective of this study is to improve the flexural performances of foam core sandwich composite via structural core modifications considering the ease of application. The performances of single core perforated and divided core perforated sandwich composites are compared with each other. The future demands of sandwich composites in recent years on aeronautics and marine industries are being increasing in their research needs and these materials has their superior properties for upgrading engineering products.

Keywords: sandwich composites, perforated cores, flexural test, single and divided core perforated

Procedia PDF Downloads 160
2522 Biological Optimization following BM-MSC Seeding of Partially Demineralized and Partially Demineralized Laser-Perforated Structural Bone Allografts Implanted in Critical Femoral Defects

Authors: S. AliReza Mirghasemi, Zameer Hussain, Mohammad Saleh Sadeghi, Narges Rahimi Gabaran, Mohamadreza Baghaban Eslaminejad

Abstract:

Background: Despite promising results have shown by osteogenic cell-based demineralized bone matrix composites, they need to be optimized for grafts that act as structural frameworks in load-bearing defects. The purpose of this experiment is to determine the effect of bone-marrow-mesenchymal-stem-cells seeding on partially demineralized laser-perforated structural allografts that have been implanted in critical femoral defects. Materials and Methods: P3 stem cells were used for graft seeding. Laser perforation in four rows of three holes was achieved. Cell-seeded grafts were incubated for one hour until they were planted into the defect. We used four types of grafts: partially demineralized only (Donly), partially demineralized stem cell seeded (DST), partially demineralized laser-perforated (DLP), and partially demineralized laser-perforated stem cell seeded (DLPST). histologic and histomorphometric analysis were performed at 12 weeks. Results: Partially demineralized laser-perforated had the highest woven bone formation within graft limits, stem cell seeded demineralized laser-perforated remained intact, and the difference between partially demineralized only and partially demineralized stem cell seeded was insignificant. At interface, partially demineralized laser-perforated and partially demineralized only had comparable osteogenesis, but partially demineralized stem cell seeded was inferior. The interface in stem cell seeded demineralized laser-perforated was almost replaced by distinct endochondral osteogenesis with higher angiogenesis in the vicinity. Partially demineralized stem cell seeded and stem cell seeded demineralized laser-perforated graft surfaces had extra vessel-ingrowth-like porosities, a sign of delayed resorption. Conclusion: This demonstrates that simple cell-based composites are not optimal and necessitates the supplementation of synergistic stipulations and surface changes.

Keywords: structural bone allograft, partial demineralization, laser perforation, mesenchymal stem cell

Procedia PDF Downloads 416
2521 Investigation of the Flow Characteristics in a Catalytic Muffler with Perforated Inlet Cone

Authors: Gyo Woo Lee, Man Young Kim

Abstract:

Emission regulations for diesel engines are being strengthened and it is impossible to meet the standards without exhaust after-treatment systems. Lack of the space in many diesel vehicles, however, make it difficult to design and install stand-alone catalytic converters such as DOC, DPF, and SCR in the vehicle exhaust systems. Accordingly, those have been installed inside the muffler to save the space, and referred to the catalytic muffler. However, that has complex internal structure with perforated plate and pipe for noise and monolithic catalyst for emission reduction. For this reason, flow uniformity and pressure drop, which affect efficiency of catalyst and engine performance, respectively, should be examined when the catalytic muffler is designed. In this work, therefore, the flow uniformity and pressure drop to improve the performance of the catalytic converter and the engine have been numerically investigated by changing various design parameters such as inlet shape, porosity, and outlet shape of the muffler using the three-dimensional turbulent flow of the incompressible, non-reacting, and steady state inside the catalytic muffler. Finally, it can be found that the shape, in which the muffler has perforated pipe inside the inlet part, has higher uniformity index and lower pressure drop than others considered in this work.

Keywords: catalytic muffler, perforated inlet cone, catalysts, perforated pipe, flow uniformity, pressure drop

Procedia PDF Downloads 327
2520 Experimental Study of the Sound Absorption of a Geopolymer Panel with a Textile Component Designed for a Railway Corridor

Authors: Ludmila Fridrichová, Roman Knížek, Pavel Němeček, Katarzyna Ewa Buczkowska

Abstract:

The design of the sound absorption panel, which consists of three layers, is presented in this study. The first layer of the panel is perforated and provides sound transmission to the inner part of the panel. The second layer is composed of a bulk material whose purpose is to absorb as much noise as possible. The third layer of the panel has two functions: the first function is to ensure the strength of the panel, and the second function is to reflect the sound back into the bulk layer. Experimental results have shown that the size of the holes in the perforated panel affects the sound absorption of the required frequency. The percentage of filling of the perforated area affects the quantity of sound absorbed.

Keywords: sound absorption, railway corridor, health, textile waste, natural fibres, concrete

Procedia PDF Downloads 19
2519 Performance Analysis of Solar Air Heater with Fins and Perforated Twisted Tape Insert

Authors: Rajesh Kumar, Prabha Chand

Abstract:

The present paper deals with the analytical investigation on the thermal and thermo-hydraulic performance of the solar air collector fitted with fins and perforated twisted tapes (PTT) of twist ratio 2 with different axial pitch ratio. The mathematical models are presented, and the effect of mass flow rate and axial pitch ratios on the thermal and effective efficiency has been discussed. The results obtained are compared with the results of the solar air heater without fins and twisted tapes. Results conveyed that the collectors with fins and perforated twisted tape perform better but at the expense of increased pressure drop. Also, twisted tape with minimum axial pitch ratio is found to be more efficient than others.

Keywords: solar air heater, thermal efficiency, twisted tape, twist ratio

Procedia PDF Downloads 267
2518 Design and Simulation of MEMS-Based Capacitive Pressure Sensors

Authors: Kirankumar B. Balavalad, Bhagyashree Mudhol, B. G. Sheeparamatti

Abstract:

MEMS sensor have gained popularity in automotive, biomedical, and industrial applications. In this paper, the design and simulation of conventional, slotted, and perforated MEMS capacitive pressure sensor is proposed. Polysilicon material is used as diaphragm material that deflects due to applied pressure. Better sensitivity is the main advantage of conventional pressure sensor as compared with other two sensors and perforated pressure sensor achieves large operating pressure range. The proposed MEMS sensor demonstrated with diaphragm length 50um, gap depth 3um is being modelled. The simulation is carried out for different types of MEMS capacitive pressure sensor using COMSOL Multiphysics and Coventor ware.

Keywords: MEMS, conventional pressure sensor, slotted and perforated diaphragm, COMSOL multiphysics, coventor ware

Procedia PDF Downloads 508
2517 Experimental Verification of Similarity Criteria for Sound Absorption of Perforated Panels

Authors: Aleksandra Majchrzak, Katarzyna Baruch, Monika Sobolewska, Bartlomiej Chojnacki, Adam Pilch

Abstract:

Scaled modeling is very common in the areas of science such as aerodynamics or fluid mechanics, since defining characteristic numbers enables to determine relations between objects under test and their models. In acoustics, scaled modeling is aimed mainly at investigation of room acoustics, sound insulation and sound absorption phenomena. Despite such a range of application, there is no method developed that would enable scaling acoustical perforated panels freely, maintaining their sound absorption coefficient in a desired frequency range. However, conducted theoretical and numerical analyses have proven that it is not physically possible to obtain given sound absorption coefficient in a desired frequency range by directly scaling only all of the physical dimensions of a perforated panel, according to a defined characteristic number. This paper is a continuation of the research mentioned above and presents practical evaluation of theoretical and numerical analyses. The measurements of sound absorption coefficient of perforated panels were performed in order to verify previous analyses and as a result find the relations between full-scale perforated panels and their models which will enable to scale them properly. The measurements were conducted in a one-to-eight model of a reverberation chamber of Technical Acoustics Laboratory, AGH. Obtained results verify theses proposed after theoretical and numerical analyses. Finding the relations between full-scale and modeled perforated panels will allow to produce measurement samples equivalent to the original ones. As a consequence, it will make the process of designing acoustical perforated panels easier and will also lower the costs of prototypes production. Having this knowledge, it will be possible to emulate in a constructed model panels used, or to be used, in a full-scale room more precisely and as a result imitate or predict the acoustics of a modeled space more accurately.

Keywords: characteristic numbers, dimensional analysis, model study, scaled modeling, sound absorption coefficient

Procedia PDF Downloads 196
2516 Numerical Analysis of a Strainer Using Porous Media Technique

Authors: Ji-Hoon Byeon, Kwon-Hee Lee

Abstract:

Strainer filter serves to block the inflow of impurities while mixed fluid is entering or exiting the piping. The filter of the strainer has a perforated structure, so that the pressure drop and the velocity change necessarily occur when the mixed fluid passes through the filter. It is possible to predict the pressure drop and velocity change of the strainer by numerical analysis by implementing all the perforated plates. However, if the size of the perforated plate exceeds a certain size, it is difficult to perform the numerical analysis, and sometimes we cannot guarantee its accuracy. In this study, we tried to predict the pressure drop and velocity change by using the porous media technique to obtain the equivalent resistance without actual implementation of the perforation shape of the strainer. Ansys-CFX, a commercial software, is used to perform the numerical analysis. The analysis procedure is as follows. Firstly, the unit pattern of the perforated plate is modeled, and the pressure drop is analyzed by varying the velocity by symmetry of the wall surface. Secondly, since the equation for obtaining resistance is a quadratic equation of pressure having unknown velocity, the viscous resistance and the inertia resistance of the perforated plate are obtained from the relationship between pressure and speed. Thirdly, by using the calculated resistance values, the values are substituted into the flat plate implemented as a two-dimensional porous media, and the accuracy is verified by comparing the pressure drop and the velocity change. Fourthly, the pressure drop and velocity change in the whole strainer are analyzed by using the resistance values obtained on the perforated plate in the actual whole strainer model. Using the porous media technique, it is found that pressure drop and velocity change can be predicted in relatively short time without modeling the overall shape of the filter. Acknowledgements: This work was supported by the Valve Center from the Regional Innovation Center(RIC) Program of Ministry of Trade, Industry & Energy (MOTIE).

Keywords: strainer, porous media, CFD, numerical analysis

Procedia PDF Downloads 374
2515 Comparison of Storage Facilities on Different Varieties of Orange Fleshed Sweet Potato Grown in Rwanda

Authors: Jean Paul Hategekimana, Dukuzumuremyi Yvonne, Mukeshimana Marthe, Alexandre Niyonshima

Abstract:

Sweet potato (Ipomoea batatas) is a very important staple food crop in Rwanda due to its high growth and consumption in all parts of the country. The effect of seven different storage conditions on the quality and nutritional composition of the three most grown and consumed varieties of orange-fleshed sweet potato (OFSP), namely Kabode, Terimbere, and Vita, were studied over a period of six weeks at Postharvest Service and Training Center of University Rwanda, Busogo Campus. The potato stored under the following conditions (zero energy cooling chamber, ground washed sweet potato, ground unwashed sweet potato, perforated washed sweet potato, perforated unwashed sweet potato, non-perforated washed sweet potato, and non-perforated unwashed sweet potato) were assessed in this study. These storage conditions are the modifications of existing methods currently used in Rwanda for suitable local climatic conditions. Hence, 30kgs of freshly harvested OFSP for each variety were bought from farmers of Gakenke and Rulindo districts and then transported to the postharvest training and service center UR-CAVM, Busogo Campus. 2.5kg of each potato sample was selected and stored under the above-mentioned storage conditions after pretreatment. Data were collected for six weeks on percent weight loss, shrinkability and the general appearance at interval of three days. The stored samples were also analyzed for moisture, crude ash, crude fiber, and reduced sugar levels during the entire storage period. Results showed the difference among the various storage conditions. It was shown that ZECC and non-perforated sacs (in the open air) storage techniques had good potential for storage of orange flesh sweet potato for up to six weeks without considerable change in physical and nutritional parameters compared to other considered conditions and, therefore, can be recommended as more useful for OSFP at farm level and during transport and market storage.

Keywords: ZECC, orange fleshed sweet potato, perforated sacs, storage conditions

Procedia PDF Downloads 68
2514 Terminal Ballistic Analysis of Non-Filled and Water-Filled Tank

Authors: M. R. Aziz, W. Kuntjoro, N. V. David

Abstract:

This paper presents the ballistic terminal study of the non-filled and water-filled aluminum tank. The objective was to determine the failure stages for both cases. The tank was impacted by fragment simulating projectile (FSP) with 260 m/s for non-filled and 972 m/s for water-filled. The aluminum tank was 3 mm thick, 150 mm wide and 750 mm long. The ends of the tank were closed with two polymethyl methacrylate (PMMA) windows. The test was conducted at the Science and Technology Research Institute for Defense (STRIDE) Batu Arang, Selangor, Malaysia. The results showed four main stages for non-filled tank, which were first contact between FSP and the tank, partially perforated, fully perforated with FSP and plug still intact and lastly fully perforated with FSP and plug separated. Meanwhile, for the water-filled tank, there were seven main stages, which were first contact between FSP and the tank, partial perforation, full perforation, drag phase, cavity phase, bounce wave event and the collapse of the cavity.

Keywords: fragment simulating projectile, high speed camera, tensile test, terminal ballistic

Procedia PDF Downloads 305
2513 Device for Mechanical Fragmentation of Organic Substrates Before Methane Fermentation

Authors: Marcin Zieliński, Marcin Dębowski, Mirosław Krzemieniewski

Abstract:

This publication presents a device designed for mechanical fragmentation of plant substrate before methane fermentation. The device is equipped with a perforated rotary cylindrical drum coated with a thermal layer, connected to a substrate feeder and driven by a motoreducer. The drum contains ball- or cylinder-shaped weights of different diameters, while its interior is mounted with lateral permanent magnets with an attractive force ranging from 100 kg to 2 tonnes per m2 of the surface. Over the perforated rotary drum, an infrared radiation generator is mounted, producing 0.2 kW to 1 kW of infrared radiation per 1 m2 of the perforated drum surface. This design reduces the energy consumption required for the biomass destruction process by 10-30% in comparison to the conventional ball mill. The magnetic field generated by the permanent magnets situated within the perforated rotary drum promotes this process through generation of free radicals that act as powerful oxidants, accelerating the decomposition rate. Plant substrate shows increased susceptibility to biodegradation when subjected to magnetic conditioning, reducing the time required for biomethanation by 25%. Additionally, the electromagnetic radiation generated by the radiator improves substrate destruction by 10% and the efficiency of the process. The magnetic field and the infrared radiation contribute synergically to the increased efficiency of destruction and conversion of the substrate.

Keywords: biomass pretreatment, mechanical fragmentation, biomass, methane fermentation

Procedia PDF Downloads 581
2512 Mesenteric Vasculitis Causing Perforated Diverticulitis Mimicking Abdominal Sepsis

Authors: Christopher Leung, Assad Zahid

Abstract:

Mesenteric vasculitis can often mimic abdominal sepsis in a postoperative setting leading to a predicament where steroids could improve mesenteric vasculitis whilst worsening abdominal sepsis. Here this study presents a unique and rare case of perforated sigmoid diverticulitis secondary to systemic vasculitis. A 68-year-old gentleman presented with perforated sigmoid diverticulitis requiring an emergency Hartmann’s procedure. Early in his postoperative course, he had painful and asymmetrical neuropathy that, after a careful history and examination, revealed a patient with mono neuritis multiplex on a background history of longstanding rheumatoid arthritis. On day seven of his postoperative course, he had rising inflammatory markers and a CT abdomen and pelvis showing fluid around the mesentery. Whilst contamination from sigmoid perforation was somewhat congruent with these signs, a diagnosis of polyarteritis nodosa, a common cause of mononeuritis multiplex, is also possible, although involvement of the large bowel in polyarteritis nodosa is extremely rare. The histopathology from the initial Hartmann’s procedure was re-examined, showing medium vessel disease vasculitis. Given his lack of fevers, absence of abdominal pain, and worsening neurology, he was given a provisional diagnosis of polyarteritis nodosa and was treated successfully, not on IV antibiotics but on steroids. Large bowel involvement of polyarteritis nodosa is extremely rare and this is the first case of polyarteritis nodosa causing perforated diverticulitis. The learning point here is to obtain a good clinical picture of a patient to identify mesenteric vasculitis as compared to abdominal sepsis as the treatment of one worsens the other.

Keywords: abdominal sepsis, diverticulitis, mesenteric vasculitis, polyarteritis nodosa

Procedia PDF Downloads 253
2511 Acute Peritonitis Caused by Perforated Appendicitis Accompanied by Synchronous Encephalopathy: A Rare Primary Presentation of Varicella Zoster Infection

Authors: Shahla Afshar Paiman, Sedigheh Madani, Zahra Hosseininezhad

Abstract:

Introduction: The most common causes of appendix luminal obstruction are fecaliths and lymphoid follicle hyperplasia. Appendicitis is a very rare Gastrointestinal complication of varicella zosterand it is mostly observed in immune-compromised patient. Case presentation: Here we reported a case of varicella zoster-related perforated appendicitis with synchronous encephalopathy as a first presentation of chickenpox in a 10-year-old boy. He had no history of immunodeficiency or predisposing factors and his diagnosis is confirmed by both serological lab tests and abdominal fluid (peritoneal secretion) PCR. Conclusion: Varicella zoster could cause appendicitis as first presentation, along with other critical complications look likes encephalopathy.

Keywords: Varicella zoster, appendicitis, encephalitis, children

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2510 Facile Synthesis of Metal Nanoparticles on Graphene via Galvanic Displacement Reaction for Sensing Application

Authors: Juree Hong, Sanggeun Lee, Jungmok Seo, Taeyoon Lee

Abstract:

We report a facile synthesis of metal nano particles (NPs) on graphene layer via galvanic displacement reaction between graphene-buffered copper (Cu) and metal ion-containing salts. Diverse metal NPs can be formed on graphene surface and their morphologies can be tailored by controlling the concentration of metal ion-containing salt and immersion time. The obtained metal NP-decorated single-layer graphene (SLG) has been used as hydrogen gas (H2) sensing material and exhibited highly sensitive response upon exposure to 2% of H2.

Keywords: metal nanoparticle, galvanic displacement reaction, graphene, hydrogen sensor

Procedia PDF Downloads 427
2509 Propane Dehydrogenation with Better Stability by a Modified Pt-Based Catalyst

Authors: Napat Hataivichian

Abstract:

The effect of transition metal doping on Pt/Al2O3 catalyst used in propane dehydrogenation reaction at 500˚C was studied. The preparation methods investigated were sequential impregnation (Pt followed by the 2nd metal or the 2nd metal followed by Pt) and co-impregnation. The metal contents of these catalysts were fixed as the weight ratio of Pt per the 2nd metal of around 0.075. These catalysts were characterized by N2-physisorption, TPR, CO-chemisorption and NH3-TPD. It was found that the impregnated 2nd metal had an effect upon reducibility of Pt due to its interaction with transition metal-containing structure. This was in agreement with the CO-chemisorption result that the presence of Pt metal, which is a result from Pt species reduction, was decreased. The total acidity of bimetallic catalysts is decreased but the strong acidity is slightly increased. It was found that the stability of bimetallic catalysts prepared by co-impregnation and sequential impregnation where the 2nd metal was impregnated before Pt were better than that of monometallic catalyst (undoped Pt one) due to the forming of Pt sites located on the transition metal-oxide modified surface. Among all preparation methods, the sequential impregnation method- having Pt impregnated before the 2nd metal gave the worst stability because this catalyst lacked the modified Pt sites and some fraction of Pt sites was covered by the 2nd metal.

Keywords: alumina, dehydrogenation, platinum, transition metal

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2508 Behaviours of Energy Spectrum at Low Reynolds Numbers in Grid Turbulence

Authors: Md Kamruzzaman, Lyazid Djenidi, R. A. Antonia

Abstract:

This paper reports an experimental investigation of the energy spectrum of turbulent velocity fields at low Reynolds numbers ( Rλ ) in grid turbulence. Hot wire measurements are carried out in grid turbulence with subjected to a 1.36:1 contraction of the wind tunnel. Three different grids are used: (i) large square perforated grid (mesh size 43.75 mm), (ii) small square perforated grid (mesh size 14 and (iii) woven mesh grid (mesh size 5mm). The results indicate that the energy spectrum at small Rλ does not follow Kolmogorov’s universal scaling. It is further found that the critical Reynolds number,Rλ,ϲ below which the scaling breaks down is around 25.

Keywords: energy spectrum, Taylor microscale, Reynolds number, turbulent kinetic energy, decay exponent

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2507 Preparation of Porous Metal Membrane by Thermal Annealing for Thin Film Encapsulation

Authors: Jaibir Sharma, Lee JaeWung, Merugu Srinivas, Navab Singh

Abstract:

This paper presents thermal annealing dewetting technique for the preparation of porous metal membrane for thin film encapsulation application. Thermal annealing dewetting experimental results reveal that pore size in porous metal membrane depend upon i.e. 1. The substrate on which metal is deposited for formation of porous metal cap membrane, 2. Melting point of metal used for porous metal cap layer membrane formation, 3. Thickness of metal used for cap layer, 4. Temperature used for porous metal membrane formation. Silver (Ag) was used as a metal for preparation of porous metal membrane by annealing the film at different temperature. Pores in porous silver film were analyzed using Scanning Electron Microscope (SEM). In order to check the usefulness of porous metal film for thin film encapsulation application, the porous silver film prepared on amorphous silicon (a-Si) was release using XeF2. Finally, guide line and structures are suggested to use this porous membrane for thin film encapsulation (TFE) application.

Keywords: dewetting, themal annealing, metal, melting point, porous

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2506 The Road to Tunable Structures: Comparison of Experimentally Characterised and Numerical Modelled Auxetic Perforated Sheet Structures

Authors: Arthur Thirion

Abstract:

Auxetic geometries allow the generation of a negative Poisson ratio (NPR) in conventional materials. This behaviour allows materials to have certain improved mechanical properties, including impact resistance and altered synclastic behaviour. This means these structures have significant potential when it comes to applications as chronic wound dressings. To this end, 6 different "perforated sheet" structure types were 3D printed. These structures all had variations of key geometrical features included cell length and angle. These were tested in compression and tension to assess their Poisson ratio. Both a positive and negative Poisson ratio was generated by the structures depending on the loading. The a/b ratio followed by θ has been shown to impact the Poisson ratio significantly. There is still a significant discrepancy between modelled and observed behaviour.

Keywords: auxetic materials, 3D printing, negative Poisson's ratio, tunable Poisson's ratio

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2505 Heavy Metal Concentration in Orchard Area, Amphawa District, Samut Songkram Province, Thailand

Authors: Sisuwan Kaseamsawat, Sivapan Choo-In

Abstract:

A study was conducted in May to July 2013 with the aim of determination of heavy metal concentration in orchard area. 60 samples were collected and analyzed for Cadmium (Cd), Copper (Cu), Lead (Pb), and Zinc (Zn) by Atomic Absorption Spectrophotometer (AAS). The heavy metal concentrations in sediment of orchards, that use chemical for Cd (1.13 ± 0.26 mg/l), Cu (8.00 ± 1.05 mg/l), Pb (13.16 ± 2.01) and Zn (37.41 ± 3.20 mg/l). The heavy metal concentrations in sediment of the orchards, that do not use chemical for Cd (1.28 ± 0.50 mg/l), Cu (7.60 ± 1.20 mg/l), Pb (29.87 ± 4.88) and Zn (21.79 ± 2.98 mg/l). Statistical analysis between heavy metal in sediment from the orchard, that use chemical and the orchard, that not use chemical were difference statistic significant of 0.5 level of significant for Cd and Pb while no statistically difference for Cu and Zn.

Keywords: heavy metal, orchard, pollution and monitoring, sediment

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2504 Use of Microbial Fuel Cell for Metal Recovery from Wastewater

Authors: Surajbhan Sevda

Abstract:

Metal containing wastewater is generated in large quintiles due to rapid industrialization. Generally, the metal present in wastewater is not biodegradable and can be accumulated in living animals, humans and plant tissue, causing disorder and diseases. The conventional metal recovery methods include chemical, physical and biological methods, but these are chemical and energy intensive. The recent development in microbial fuel cell (MFC) technology provides a new approach for metal recovery; this technology offers a flexible platform for both reduction and oxidation reaction oriented process. The use of MFCs will be a new platform for more efficient and low energy approach for metal recovery from the wastewater. So far metal recover was extensively studied using chemical, physical and biological methods. The MFCs present a new and efficient approach for removing and recovering metals from different wastewater, suggesting the use of different electrode for metal recovery can be a new efficient and effective approach.

Keywords: metal recovery, microbial fuel cell, wastewater, bioelectricity

Procedia PDF Downloads 218
2503 Development of Locally Fabricated Honey Extracting Machine

Authors: Akinfiresoye W. A., Olarewaju O. O., Okunola, Okunola I. O.

Abstract:

An indigenous honey-extracting machine was designed, fabricated and evaluated at the workshop of the department of Agricultural Technology, Federal Polytechnic, Ile-Oluji, Nigeria using locally available materials. It has the extraction unit, the presser, the honey collector and the frame. The harvested honeycomb is placed inside the cylindrical extraction unit with perforated holes. The press plate was then placed on the comb while the hydraulic press of 3 tons was placed on it, supported by the frame. The hydraulic press, which is manually operated, forces the oil out of the extraction chamber through the perforated holes into the honey collector positioned at the lowest part of the extraction chamber. The honey-extracting machine has an average throughput of 2.59 kg/min and an efficiency of about 91%. The cost of producing the honey extracting machine is NGN 31, 700: 00, thirty-one thousand and seven hundred nairas only or $70 at NGN 452.8 to a dollar. This cost is affordable to beekeepers and would-be honey entrepreneurs. The honey-extracting machine is easy to operate and maintain without any complex technical know-how.

Keywords: honey, extractor, cost, efficiency

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2502 Investigation of Cylindrical Multi-Layer Hybrid Plasmonic Waveguides

Authors: Prateeksha Sharma, V. Dinesh Kumar

Abstract:

Performances of cylindrical multilayer hybrid plasmonic waveguides have been investigated in detail considering their structural and material aspects. Characteristics of hybrid metal insulator metal (HMIM) and hybrid insulator metal insulator (HIMI) waveguides have been compared on the basis of propagation length and confinement factor. Necessity of this study is to understand newer kind of waveguides that overcome the limitations of conventional waveguides. Investigation reveals that sub wavelength confinement can be obtained in two low dielectric spacer layers. This study provides gateway for many applications such as nano lasers, interconnects, bio sensors and optical trapping etc.

Keywords: hybrid insulator metal insulator, hybrid metal insulator metal, nano laser, surface plasmon polariton

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2501 A Systamatic Review on Experimental, FEM Analysis and Simulation of Metal Spinning Process

Authors: Amol M. Jadhav, Sharad S. Chudhari, S. S. Khedkar

Abstract:

This review presents a through survey of research paper work on the experimental analysis, FEM Analysis & simulation of the metal spinning process. In this literature survey all the papers being taken from Elsevier publication and most of the from journal of material processing technology. In a last two decade or so, metal spinning process gradually used as chip less formation for the production of engineering component in a small to medium batch quantities. The review aims to provide include into the experimentation, FEM analysis of various components, simulation of metal spinning process and act as guide for research working on metal spinning processes. The review of existing work has several gaps in current knowledge of metal spinning processes. The evaluation of experiment is thickness strain, the spinning force, the twisting angle, the surface roughness of the conventional & shear metal spinning process; the evaluation of FEM of metal spinning to path definition with sufficient fine mesh to capture behavior of work piece; The evaluation of feed rate of roller, direction of roller,& type of roller stimulated. The metal spinning process has the more flexible to produce a wider range of product shape & to form more challenge material.

Keywords: metal spinning, FEM analysis, simulation of metal spinning, mechanical engineering

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2500 Reduction in Hot Metal Silicon through Statistical Analysis at G-Blast Furnace, Tata Steel Jamshedpur

Authors: Shoumodip Roy, Ankit Singhania, Santanu Mallick, Abhiram Jha, M. K. Agarwal, R. V. Ramna, Uttam Singh

Abstract:

The quality of hot metal at any blast furnace is judged by the silicon content in it. Lower hot metal silicon not only enhances process efficiency at steel melting shops but also reduces hot metal costs. The Hot metal produced at G-Blast furnace Tata Steel Jamshedpur has a significantly higher Si content than Benchmark Blast furnaces. The higher content of hot metal Si is mainly due to inferior raw material quality than those used in benchmark blast furnaces. With minimum control over raw material quality, the only option left to control hot metal Si is via optimizing the furnace parameters. Therefore, in order to identify the levers to reduce hot metal Si, Data mining was carried out, and multiple regression models were developed. The statistical analysis revealed that Slag B3{(CaO+MgO)/SiO2}, Slag Alumina and Hot metal temperature are key controllable parameters affecting hot metal silicon. Contour Plots were used to determine the optimum range of levels identified through statistical analysis. A trial plan was formulated to operate relevant parameters, at G blast furnace, in the identified range to reduce hot metal silicon. This paper details out the process followed and subsequent reduction in hot metal silicon by 15% at G blast furnace.

Keywords: blast furnace, optimization, silicon, statistical tools

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2499 A Review on Aluminium Metal Matric Composites

Authors: V. Singh, S. Singh, S. S. Garewal

Abstract:

Metal matrix composites with aluminum as the matrix material have been heralded as the next great development in advanced engineering materials. Aluminum metal matrix composites (AMMC) refer to the class of light weight high performance material systems. Properties of AMMCs can be tailored to the demands of different industrial applications by suitable combinations of matrix, reinforcement and processing route. AMMC finds its application in automotive, aerospace, defense, sports and structural areas. This paper presents an overview of AMMC material systems on aspects relating to processing, types and applications with case studies.

Keywords: aluminum metal matrix composites, applications of aluminum metal matrix composites, lighting material processing of aluminum metal matrix composites

Procedia PDF Downloads 465