Search results for: knowledge flow
2544 Investigation of Buoyant Parameters of k-ε Turbulence Model in Gravity Stratified Flows
Authors: A. Majid Bahari, Kourosh Hejazi
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Different variants for buoyancy-affected terms in k-ε turbulence model have been utilized to predict the flow parameters more accurately, and investigate applicability of alternative k-ε turbulence buoyant closures in numerical simulation of a horizontal gravity current. The additional non-isotropic turbulent stress due to buoyancy has been considered in production term, based on Algebraic Stress Model (ASM). In order to account for turbulent scalar fluxes, general gradient diffusion hypothesis has been used along with Boussinesq gradient diffusion hypothesis with a variable turbulent Schmidt number and additional empirical constant c3ε.To simulate buoyant flow domain a 2D vertical numerical model (WISE, Width Integrated Stratified Environments), based on Reynolds- Averaged Navier-Stokes (RANS) equations, has been deployed and the model has been further developed for different k-ε turbulence closures. Results are compared against measured laboratory values of a saline gravity current to explore the efficient turbulence model.
Keywords: Buoyant flows, Buoyant k-ε turbulence model, saline gravity current.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 39092543 Investigating the Behavior of Underground Structures in the Event of an Earthquake
Authors: Davoud Beheshtizadeh, Farzin Malekpour
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The progress of technology and producing new machinery have made a big change in excavation operations and construction of underground structures. The limitations of space and some other economic, politic and military considerations gained the attention of most developed and developing countries towards the construction of these structures for mine, military, and development objectives. Underground highways, tunnels, subways, oil reservoir resources, fuels, nuclear wastes burying reservoir and underground stores are increasingly developing and being used in these countries. The existence and habitability of the cities depend on these underground installations or in other words these vital arteries. Stopping the flow of water, gas leakage and explosion, collapsing of sewage paths, etc., resulting from the earthquake are among the factors that can severely harm the environment and increase the casualty. Lack of sewage network and complete stoppage of the flow of water in Bam (Iran) is a good example of this kind. In this paper, we investigate the effect of wave orientation on structures and deformation of them and the effect of faulting on underground structures, and then, we study resistance of reinforced concrete against earthquake, simulate two different samples, analyze the result and point out the importance of paying attention to underground installations.
Keywords: Earthquake, underground structures, underground installations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9672542 CFD Study on the Effect of Primary Air on Combustion of Simulated MSW Process in the Fixed Bed
Authors: Rui Sun, Tamer M. Ismail, Xiaohan Ren, M. Abd El-Salam
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Incineration of municipal solid waste (MSW) is one of the key scopes in the global clean energy strategy. A computational fluid dynamics (CFD) model was established in order to reveal these features of the combustion process in a fixed porous bed of MSW. Transporting equations and process rate equations of the waste bed were modeled and set up to describe the incineration process, according to the local thermal conditions and waste property characters. Gas phase turbulence was modeled using k-ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The heterogeneous reaction rates were determined using Arrhenius eddy dissipation and the Arrhenius-diffusion reaction rates. The effects of primary air flow rate and temperature in the burning process of simulated MSW are investigated experimentally and numerically. The simulation results in bed are accordant with experimental data well. The model provides detailed information on burning processes in the fixed bed, which is otherwise very difficult to obtain by conventional experimental techniques.
Keywords: Computational Fluid Dynamics (CFD) model, Waste Incineration, Municipal Solid Waste (MSW), Fixed Bed, Primary air.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27182541 Public Art and Public Space in an Emerging Knowledge Economy: The Case of Doha
Authors: Anna Grichting, Sara Al Sada, Angelica Caccam, Urshi Khan
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Qatar, a Gulf country highly dependent on its oil and gas revenues – is looking to innovate, diversify, and ultimately reach its aim of creating a knowledge economy to prepare for its post-oil era. One area that the country is investing in is Contemporary Art, and world renowned artists such as Damien Hirst and Richard Serra – have been commissioned to design site-specific art for the public spaces of the city of Doha as well as in more remote desert locations. This research discusses the changing presence, role and context of public art in Doha, both from a historical and cultural overview, and the different forms and media as well as the typologies of urban and public spaces in which the art is installed. It examines the process of implementing site-specific artworks, looking at questions of scale, history, social meaning and formal aesthetics. The methodologies combine theoretical research on the understanding of public art and its role and placement in public space, as well as empirical research on contemporary public art projects in Doha, based on documentation and interviews and as well as site and context analysis of the urban or architectural spaces within which the art is situated. Surveys and interviews – using social media - in different segments of the contemporary Qatari society, including all nationalities and social groups, are used to measure and qualify the impacts and effects on the population.
Keywords: Contemporary Public Art, Knowledge Economy, Public Realm, Site Specific Art Works.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23732540 Financial Literacy of Students of Finance: An Empirical Study from the Czech Republic
Authors: Barbora Chmelíková
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Financial literacy is a widely discussed topic on the national and international level by governments, organizations and academia. For this reason, this study analyses financial knowledge, financial behavior, and financial attitudes of students of finance. The aim of the paper is to determine whether the financial literacy of university students studying finance differs from the level of financial literacy in selected OECD countries. The research was conducted at Masaryk University in the Czech Republic. The empirical study comprises questions related to several aspects of financial literacy, such as financial knowledge, personal finance behavior, or decisionmaking. The results indicate that improvement in financial literacy of university students is still required, even though their major is finance related.Keywords: Financial literacy, financial behavior, personal finance management, university students.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23932539 Study of Fire Propagation and Soot Flow in a Pantry Car of Railway Locomotive
Authors: Juhi Kaushik, Abhishek Agarwal, Manoj Sarda, Vatsal Sanjay, Arup Kumar Das
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Fire accidents in trains bring huge disaster to human life and property. Evacuation becomes a major challenge in such incidents owing to confined spaces, large passenger density and trains moving at high speeds. The pantry car in Indian Railways trains carry inflammable materials like cooking fuel and LPG and electrical fittings. The pantry car is therefore highly susceptible to fire accidents. Numerical simulations have been done in a pantry car of Indian locomotive train using computational fluid dynamics based software. Different scenarios of a fire outbreak have been explored by varying Heat Release Rate per Unit Area (HRRPUA) of the fire source, introduction of exhaust in the cooking area, and taking a case of an air conditioned pantry car. Temporal statures of flame and soot have been obtained for each scenario and differences have been studied and reported. Inputs from this study can be used to assess casualties in fire accidents in locomotive trains and development of smoke control/detection systems in Indian trains.Keywords: Fire propagation, flame contour, pantry fire, soot flow.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18142538 A PI Controller for Enhancing the Transient Stability of Multi Pulse Inverter Based Static Synchronous Series Compensator (SSSC) With Superconducting Magnetic Energy Storage(SMES)
Authors: S. Padma, Dr. R. Lakshmipathi, K. Ramash Kumar, P. Nandagopal
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The power system network is becoming more complex nowadays and it is very difficult to maintain the stability of the system. Today-s enhancement of technology makes it possible to include new energy storage devices in the electric power system. In addition, with the aid of power electronic devices, it is possible to independently exchange active and reactive power flow with the utility grid. The main purpose of this paper proposes a Proportional – Integral (PI) control based 48 – pulse Inverter based Static Synchronous Series Compensator (SSSC) with and without Superconducting Magnetic Energy Storage (SMES) used for enhancing the transient stability and regulating power flow in automatic mode. Using a test power system through the dynamic simulation in Matlab/Simulink platform validates the performance of the proposed SSSC with and without SMES system.Keywords: Flexible AC transmission system (FACTS), PIControl, Superconducting Magnetic Energy Storage (SMES), Static Synchronous Series Compensator (SSSC).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23542537 Sustainability Management for Wine Production: A Case of Thailand
Authors: Muthatakul Metasit, Setthasakko Watchaneeporn
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At present, increased concerns about global environmental problems have magnified the importance of sustainability management. To move towards sustainability, companies need to look at everything from a holistic perspective in order to understand the interconnections between economic growth and environmental and social sustainability. This paper aims to gain an understanding of key determinants that drive sustainability management and barriers that hinder its development. It employs semi-structured interviews with key informants, site observation and documentation. The informants are production, marketing and environmental managers of the leading wine producer, which aims to become an Asia-s leader in wine & wine based products. It is found that corporate image and top management leadership are the primary factors influencing the adoption of sustainability management. Lack of environmental knowledge and inefficient communication are identified as barriers.Keywords: Environmental, knowledge; Sustainability management; Top management leadership; Wine industry
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20602536 Genetic Programming Approach to Hierarchical Production Rule Discovery
Authors: Basheer M. Al-Maqaleh, Kamal K. Bharadwaj
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Automated discovery of hierarchical structures in large data sets has been an active research area in the recent past. This paper focuses on the issue of mining generalized rules with crisp hierarchical structure using Genetic Programming (GP) approach to knowledge discovery. The post-processing scheme presented in this work uses flat rules as initial individuals of GP and discovers hierarchical structure. Suitable genetic operators are proposed for the suggested encoding. Based on the Subsumption Matrix(SM), an appropriate fitness function is suggested. Finally, Hierarchical Production Rules (HPRs) are generated from the discovered hierarchy. Experimental results are presented to demonstrate the performance of the proposed algorithm.Keywords: Genetic Programming, Hierarchy, Knowledge Discovery in Database, Subsumption Matrix.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14512535 Mixed Convection Enhancement in a 3D Lid-Driven Cavity Containing a Rotating Cylinder by Applying an Artificial Roughness
Authors: Ali Khaleel Kareem, Shian Gao, Ahmed Qasim Ahmed
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A numerical investigation of unsteady mixed convection heat transfer in a 3D moving top wall enclosure, which has a central rotating cylinder and uses either artificial roughness on the bottom hot plate or smooth bottom hot plate to study the heat transfer enhancement, is completed for fixed circular cylinder, and anticlockwise and clockwise rotational speeds, -1 ≤ Ω ≤ 1, at Reynolds number of 5000. The top lid-driven wall was cooled, while the other remaining walls that completed obstructed cubic were kept insulated and motionless. A standard k-ε model of Unsteady Reynolds-Averaged Navier-Stokes (URANS) method is involved to deal with turbulent flow. It has been clearly noted that artificial roughness can strongly control the thermal fields and fluid flow patterns. Ultimately, the heat transfer rate has been dramatically increased by involving artificial roughness on the heated bottom wall in the presence of rotating cylinder.Keywords: Artificial roughness, Lid-driven cavity, Mixed convection heat transfer, Rotating cylinder, URANS method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11552534 Performance Evaluation of a ‘Priority-Controlled’ Intersection Converted to Signal-Controlled Intersection
Authors: Ezenwa Chinenye Amanamba
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There is a call to ensure that the issues of safety and efficient throughput are considered during design; the solutions to these issues can also be retrofitted at locations where they were not captured during design, but have become problems to road users over time. This paper adopts several methods to analyze the performance of an intersection which was formerly a ‘priority-controlled’ intersection, but has now been converted to a ‘signal-controlled’ intersection. Extensive review of literature helped form the basis for result analysis and discussion. The Ikot-Ekpene/Anagha-Ezikpe intersection, located at the heart of Umuahia was adopted as case study; considering the high traffic volume on the route. Anecdotal evidence revealed that traffic signals imposed enormous delays at the intersection, especially for traffic on the major road. The major road has arrival flow which surpasses the saturation flow obtained from modelling of the isolated signalized intersection. Similarly, there were several geometric elements that did not agree with the specific function of the road. A roundabout, particularly flower roundabout was recommended as a better traffic control measure.Keywords: Highway function, level of service, roundabout, traffic delays, Umuahia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11082533 Gyrotactic Microorganisms Mixed Convection Nanofluid Flow along an Isothermal Vertical Wedge in Porous Media
Authors: A. Mahdy
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The main objective of the present article is to explore the state of mixed convection nanofluid flow of gyrotactic microorganisms from an isothermal vertical wedge in porous medium. In our pioneering investigation, the easiest possible boundary conditions have been employed, in other words when the temperature, the nanofluid and motile microorganisms’ density have been considered to be constant on the wedge wall. Adding motile microorganisms to the nanofluid tends to enhance microscale mixing, mass transfer, and improve the nanofluid stability. Upon the Oberbeck–Boussinesq approximation and non-similarity transmutation, the paradigm of nonlinear equations are obtained and tackled numerically by using the R.K. Gill and shooting methods to obtain the dimensionless velocity, temperature, nanoparticle concentration and motile microorganisms density together with the reduced Sherwood, Nusselt, and numbers. Bioconvection parameters have strong effect upon the motile microorganism, heat, and volume fraction of nanoparticle transport rates. In the case when bioconvection is neglected, the obtained computations were found in very good agreement with the previous published data.
Keywords: Bioconvection, wedge, gyrotactic microorganisms, porous media, nanofluid, mixed.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15382532 Thermophysical and Heat Transfer Performance of Covalent and Noncovalent Functionalized Graphene Nanoplatelet-Based Water Nanofluids in an Annular Heat Exchanger
Authors: Hamed K. Arzani, Ahmad Amiri, Hamid K. Arzani, Salim Newaz Kazi, Ahmad Badarudin
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The new design of heat exchangers utilizing an annular distributor opens a new gateway for realizing higher energy optimization. To realize this goal, graphene nanoplatelet-based water nanofluids with promising thermophysical properties were synthesized in the presence of covalent and noncovalent functionalization. Thermal conductivity, density, viscosity and specific heat capacity were investigated and employed as a raw data for ANSYS-Fluent to be used in two-phase approach. After validation of obtained results by analytical equations, two special parameters of convective heat transfer coefficient and pressure drop were investigated. The study followed by studying other heat transfer parameters of annular pass in the presence of graphene nanopletelesbased water nanofluids at different weight concentrations, input powers and temperatures. As a result, heat transfer performance and friction loss are predicted for both synthesized nanofluids.Keywords: Heat transfer, nanofluid, turbulent flow, forced convection flow, graphene nanoplatelet.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21712531 Topology of Reverse Von-Kármán Vortex Street in the Wake of a Swimming Whale Shark
Authors: Arash Taheri
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In this paper, effects of the ventral body planform of a swimming whale shark on the formation of ‘reverse von-Kármán vortex street’ behind the aquatic animal are studied using Fluid-Structure Interaction (FSI) approach. In this regard, incompressible Navier-Stokes equations around the whale shark’s body with a prescribed deflection dynamics are solved with the aid of Boundary Data Immersion Method (BDIM) and Implicit Large Eddy Simulation (ILES) turbulence treatment by WaterLily.jl solver; fully-written in Julia programming language. The whale shark flow simulations here are performed at high Reynolds number, i.e. 1.4 107 corresponding to the swimming of a 10 meter-whale shark at an average speed of 5 km/h. For comparison purposes, vortical flow generation behind a silky shark with a streamlined forehead eidonomy is also simulated at high Reynolds number, Re = 2 106, corresponding to the swimming of a 2 meter-silky shark at an average speed of 3.6 km/h. The results depict formation of distinct wake topologies behind the swimming sharks depending on the travelling wave oscillating amplitudes.
Keywords: Whale shark, vortex street, BDIM, FSI, functional eidonomy, bionics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12802530 Effect of Recycle Gas on Activity and Selectivity of Co-Ru/Al2O3 Catalyst in Fischer- Tropsch Synthesis
Authors: A.A.Rohani, B.Hatami, L.Jokar, F.khorasheh, A.A.Safekordi
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In industrial scale of Gas to Liquid (GTL) process in Fischer-Tropsch (FT) synthesis, a part of reactor outlet gases such as CO2 and CH4 as side reaction products, is usually recycled. In this study, the influence of CO2 and CH4 on the performance and selectivity of Co-Ru/Al2O3 catalyst is investigated by injection of these gases (0-20 vol. % of feed) to the feed stream. The effect of temperature and feed flow rate, are also inspected. The results show that low amounts of CO2 in the feed stream, doesn`t change the catalyst activity significantly but increasing the amount of CO2 (more than 10 vol. %) cause the CO conversion to decrease and the selectivity of heavy components to increase. Methane acts as an inert gas and doesn`t affect the catalyst performance. Increasing feed flow rate has negative effect on both CO conversion and heavy component selectivity. By raising the temperature, CO conversion will increase but there are more volatile components in the product. The effect of CO2 on the catalyst deactivation is also investigated carefully and a mechanism is suggested to explain the negative influence of CO2 on catalyst deactivation.Keywords: Alumina, Carbon dioxide, Cobalt catalyst, Conversion, Fischer Tropsch, Selectivity
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19762529 Towards An Integrated Model for Academia- Industry Interface in India
Authors: Vinay K. Nangia, Cashmira Pramanik
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Academia-industry relationship is not like that of technology donator-acceptor, but is of interactive and collaborative nature, acknowledging and ensuring mutual respect for each other-s role and contributions with an eye to attaining the true purpose of such relationships, namely, bringing about research-outcome synergy. Indeed, academia-industry interactions are a system that requires active and collaborative participations of all the stakeholders. This paper examines various issues associated with academic institutions and industry collaboration with special attention to the nature of resources and potentialities of stakeholders in the context of knowledge management. This paper also explores the barriers of academia-industry interaction. It identifies potential areas where industry-s participation with academia would be most effective for synergism. Lastly, this paper proposes an integrated model of several new collaborative approaches that are possible, mainly in the Indian scenario to strengthen academia-industry interface.Keywords: academia-industry, interface, knowledge economy, technology transfer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 61922528 Machine Learning Methods for Network Intrusion Detection
Authors: Mouhammad Alkasassbeh, Mohammad Almseidin
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Network security engineers work to keep services available all the time by handling intruder attacks. Intrusion Detection System (IDS) is one of the obtainable mechanisms that is used to sense and classify any abnormal actions. Therefore, the IDS must be always up to date with the latest intruder attacks signatures to preserve confidentiality, integrity, and availability of the services. The speed of the IDS is a very important issue as well learning the new attacks. This research work illustrates how the Knowledge Discovery and Data Mining (or Knowledge Discovery in Databases) KDD dataset is very handy for testing and evaluating different Machine Learning Techniques. It mainly focuses on the KDD preprocess part in order to prepare a decent and fair experimental data set. The J48, MLP, and Bayes Network classifiers have been chosen for this study. It has been proven that the J48 classifier has achieved the highest accuracy rate for detecting and classifying all KDD dataset attacks, which are of type DOS, R2L, U2R, and PROBE.
Keywords: IDS, DDoS, MLP, KDD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7272527 Airfoils Aerodynamic Efficiency Study in Heavy Rain via Two Phase Flow Approach
Authors: M. Ismail, Cao Yihua, Zhao Ming
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Heavy rainfall greatly affects the aerodynamic performance of the aircraft. There are many accidents of aircraft caused by aerodynamic efficiency degradation by heavy rain. In this Paper we have studied the heavy rain effects on the aerodynamic efficiency of NACA 64-210 & NACA 0012 airfoils. For our analysis, CFD method and preprocessing grid generator are used as our main analytical tools, and the simulation of rain is accomplished via two phase flow approach-s Discrete Phase Model (DPM). Raindrops are assumed to be non-interacting, non-deforming, non-evaporating and non-spinning spheres. Both airfoil sections exhibited significant reduction in lift and increase in drag for a given lift condition in simulated rain. The most significant difference between these two airfoils was the sensitivity of the NACA 64-210 to liquid water content (LWC), while NACA 0012 performance losses in the rain environment is not a function of LWC . It is expected that the quantitative information gained in this paper will be useful to the operational airline industry and greater effort such as small scale and full scale flight tests should put in this direction to further improve aviation safety.
Keywords: airfoil, discrete phase modeling, heavy rain, Reynolds number
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 36412526 Improving Urban Mobility: Analyzing Impacts of Connected and Automated Vehicles on Traffic and Emissions
Authors: Saad Roustom, Hajo Ribberink
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In most cities in the world, traffic has increased strongly over the last decades, causing high levels of congestion and deteriorating inner-city air quality. This study analyzes the impact of connected and automated vehicles (CAVs) on traffic performance and greenhouse gas (GHG) emissions under different CAV penetration rates in mixed fleet environments of CAVs and driver-operated vehicles (DOVs) and under three different traffic demand levels. Utilizing meso-scale traffic simulations of the City of Ottawa, Canada, the research evaluates the traffic performance of three distinct CAV driving behaviors—Cautious, Normal, and Aggressive—at penetration rates of 25%, 50%, 75%, and 100%, across three different traffic demand levels. The study employs advanced correlation models to estimate GHG emissions. The results reveal that Aggressive and Normal CAVs generally reduce traffic congestion and GHG emissions, with their benefits being more pronounced at higher penetration rates (50% to 100%) and elevated traffic demand levels. On the other hand, Cautious CAVs exhibit an increase in both traffic congestion and GHG emissions. However, results also show deteriorated traffic flow conditions when introducing 25% penetration rates of any type of CAVs. Aggressive CAVs outperform all other driving at improving traffic flow conditions and reducing GHG emissions. The findings of this study highlight the crucial role CAVs can play in enhancing urban traffic performance and mitigating the adverse impact of transportation on the environment. This research advocates for the adoption of effective CAV-related policies by regulatory bodies to optimize traffic flow and reduce GHG emissions. By providing insights into the impact of CAVs, this study aims to inform strategic decision-making and stimulate the development of sustainable urban mobility solutions.
Keywords: Connected and automated vehicles, congestion, GHG emissions, mixed fleet environment, traffic performance, traffic simulations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1052525 Effects of Mixed Convection and Double Dispersion on Semi Infinite Vertical Plate in Presence of Radiation
Authors: A.S.N.Murti, D.R.V.S.R.K. Sastry, P.K. Kameswaran, T. Poorna Kantha
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In this paper, the effects of radiation, chemical reaction and double dispersion on mixed convection heat and mass transfer along a semi vertical plate are considered. The plate is embedded in a Newtonian fluid saturated non - Darcy (Forchheimer flow model) porous medium. The Forchheimer extension and first order chemical reaction are considered in the flow equations. The governing sets of partial differential equations are nondimensionalized and reduced to a set of ordinary differential equations which are then solved numerically by Fourth order Runge– Kutta method. Numerical results for the detail of the velocity, temperature, and concentration profiles as well as heat transfer rates (Nusselt number) and mass transfer rates (Sherwood number) against various parameters are presented in graphs. The obtained results are checked against previously published work for special cases of the problem and are found to be in good agreement.Keywords: Radiation, Chemical reaction, Double dispersion, Mixed convection, Heat and Mass transfer
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17132524 The Influence of Swirl Burner Geometry on the Sugar-Cane Bagasse Injection and Burning
Authors: Juan H. Sosa-Arnao, Daniel J. O. Ferreira, Caice G. Santos, Justo E. Alvarez, Leonardo P. Rangel, Song W. Park
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A comprehensive CFD model is developed to represent heterogeneous combustion and two burner designs of supply sugar-cane bagasse into a furnace. The objective of this work is to compare the insertion and burning of a Brazilian south-eastern sugar-cane bagasse using a new swirl burner design against an actual geometry under operation. The new design allows control the particles penetration and scattering inside furnace by adjustment of axial/tangential contributions of air feed without change their mass flow. The model considers turbulence using RNG k-, combustion using EDM, radiation heat transfer using DTM with 16 ray directions and bagasse particle tracking represented by Schiller-Naumann model. The obtained results are favorable to use of new design swirl burner because its axial/tangential control promotes more penetration or more scattering than actual design and allows reproduce the actual design operation without change the overall mass flow supply.Keywords: Comprehensive CFD model, sugar-cane bagasse combustion, swirl burner.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24342523 Thermal Performance Analysis of Nanofluids in Microchannel Heat Sinks
Authors: Manay E., Sahin B., Yilmaz M., Gelis K.
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In the present study, the pressure drop and laminar convection heat transfer characteristics of nanofluids in microchannel heat sink with square duct are numerically investigated. The water based nanofluids created with Al2O3 and CuO particles in four different volume fractions of 0%, 0.5%, 1%, 1.5% and 2% are used to analyze their effects on heat transfer and the pressure drop. Under the laminar, steady-state flow conditions, the finite volume method is used to solve the governing equations of heat transfer. Mixture Model is considered to simulate the nanofluid flow. For verification of used numerical method, the results obtained from numerical calculations were compared with the results in literature for both pure water and the nanofluids in different volume fractions. The distributions of the particles in base fluid are assumed to be uniform. The results are evaluated in terms of Nusselt number, the pressure drop and heat transfer enhancement. Analysis shows that the nanofluids enhance heat transfer while the Reynolds number and the volume fractions are increasing. The best overall enhancement was obtained at φ=%2 and Re=100 for CuO-water nanofluid.
Keywords: Microchannel Heat Sink, Nanofluid, Heat transfer enhancement, pressure drop
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 35772522 Transient Hydrodynamic and Thermal Behaviors of Fluid Flow in a Vertical Porous Microchannel under the Effect of Hyperbolic Heat Conduction Model
Authors: A. F. Khadrawi
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The transient hydrodynamics and thermal behaviors of fluid flow in open-ended vertical parallel-plate porous microchannel are investigated semi-analytically under the effect of the hyperbolic heat conduction model. The model that combines both the continuum approach and the possibility of slip at the boundary is adopted in the study. The Effects of Knudsen number , Darcy number , and thermal relaxation time on the microchannel hydrodynamics and thermal behaviors are investigated using the hyperbolic heat conduction models. It is found that as increases the slip in the hydrodynamic and thermal boundary condition increases. This slip in the hydrodynamic boundary condition increases as increases. Also, the slip in the thermal boundary condition increases as decreases especially the early stage of time.Keywords: free convection, hyperbolic heat conduction, macroscopic heat conduction models in microchannel, porous media, vertical microchannel, microchannel thermal, hydrodynamic behavior.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19272521 Information Sharing to Transformation: Antecedents of Collaborative Networked Learning in Manufacturing
Authors: Wee Hock Quik, Nevan Wright
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Collaborative networked learning (hereafter CNL) was first proposed by Charles Findley in his work “Collaborative networked learning: online facilitation and software support" as part of instructional learning for the future of the knowledge worker. His premise was that through electronic dialogue learners and experts could interactively communicate within a contextual framework to resolve problems, and/or to improve product or process knowledge. Collaborative learning has always been the forefront of educational technology and pedagogical research, but not in the mainstream of operations management. As a result, there is a large disparity in the study of CNL, and little is known about the antecedents of network collaboration and sharing of information among diverse employees in the manufacturing environment. This paper presents a model to bridge the gap between theory and practice. The objective is that manufacturing organizations will be able to accelerate organizational learning and sharing of information through various collaborativeKeywords: Collaborative networked learning, Collaborative technologies, Organizational learning, Synchronous and asynchronous networked learning.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17002520 21st Century Islam: Global Challenges of Islamic Representation and Knowledge Acquisition
Authors: M. M. Muhammed, O. Khuzaima
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This research examined and outlined some of the challenges facing Islam and Muslims in the 21st century, considering global Islamic representation and knowledge acquisition as key objectives. It was observed that the Western media misrepresentation of Islam and the Western ethos embodied by the acquisition of western civilisation are major challenges faced by Islam and Muslims today. The problem of sectarianism, decline in the socio-economic power of Muslim communities and the archaic nature of the Islamic creed were recorded as major actors to the evolving global Islamic issues. It was therefore concluded that Islam is not the reason for these challenges, rather the action of some Muslims and non-Muslims were the contributing factors to the pandemics faced by Islam and Muslims. Some relevant recommendations were made to the Islamic world that could serve as effectual solutions to these lingering problems.
Keywords: Islam, challenges, Misrepresentation, twenty-first century.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19172519 Experimental Study of Fuel Tank Filling
Authors: Maurizio Mastroianni, Lou Savoni, Paul Henshaw, Gary W. Rankin
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The refueling of a transparent rectangular fuel tank fitted with a standard filler pipe and roll-over valve was experimentally studied. A fuel-conditioning cart, capable of handling fuels of different Reid vapor pressure at a constant temperature, was used to dispense fuel at the desired rate. The experimental protocol included transient recording of the tank and filler tube pressures while video recording the flow patterns in the filler tube and tank during the refueling process. This information was used to determine the effect of changes in the vent tube diameter, fuel-dispense flow rate and fuel Reid vapor pressure on the pressure-time characteristics and the occurrence of premature fuel filling shut-off and fuel spill-back. Pressure-time curves for the case of normal shut-off demonstrated the classic, three-phase characteristic noted in the literature. The variation of the maximum values of tank dome and filler tube pressures are analyzed in relation to the occurrence of premature shut-off.Keywords: experimental study, fuel tank filling, premature shutoff, spill-back
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 42042518 Virtual Mechanical Engineering Education – A Case Study
Authors: S. H. R. Lo
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Virtual engineering technology has undergone rapid progress in recent years and is being adopted increasingly by manufacturing companies of many engineering disciplines. There is an increasing demand from industry for qualified virtual engineers. The qualified virtual engineers should have the ability of applying engineering principles and mechanical design methods within the commercial software package environment. It is a challenge to the engineering education in universities which traditionally tends to lack the integration of knowledge and skills required for solving real world problems. In this paper, a case study shows some recent development of a MSc Mechanical Engineering course at Department of Engineering and Technology in MMU, and in particular, two units Simulation of Mechanical Systems(SMS) and Computer Aided Fatigue Analysis(CAFA) that emphasize virtual engineering education and promote integration of knowledge acquisition, skill training and industrial application.
Keywords: Computational modelling and simulation, mechanical engineering education.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24432517 Modelling a Hospital as a Queueing Network: Analysis for Improving Performance
Authors: Emad Alenany, M. Adel El-Baz
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In this paper, the flow of different classes of patients into a hospital is modelled and analyzed by using the queueing network analyzer (QNA) algorithm and discrete event simulation. Input data for QNA are the rate and variability parameters of the arrival and service times in addition to the number of servers in each facility. Patient flows mostly match real flow for a hospital in Egypt. Based on the analysis of the waiting times, two approaches are suggested for improving performance: Separating patients into service groups, and adopting different service policies for sequencing patients through hospital units. The separation of a specific group of patients, with higher performance target, to be served separately from the rest of patients requiring lower performance target, requires the same capacity while improves performance for the selected group of patients with higher target. Besides, it is shown that adopting the shortest processing time and shortest remaining processing time service policies among other tested policies would results in, respectively, 11.47% and 13.75% reduction in average waiting time relative to first come first served policy.Keywords: Queueing network, discrete-event simulation, health applications, SPT.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15292516 Application of “Streamlined” Material Accounting to Estimate Environmental Impact
Authors: Paul Osmond
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This paper reports a new application of material accounting techniques to characterise and quantify material stocks and flows at the “neighbourhood" scale. The study area is the main campus of the University of New South Wales in Sydney, Australia. The system boundary is defined by the urban structural unit (USU), a typological construct devised to facilitate assessment of the metabolism of urban systems. A streamlined material flow analysis (MFA) was applied to quantify the stocks and flows of key construction materials within the campus USU over time, drawing on empirical data from a major campus development project. The results are reviewed to assess the efficacy of the method in supporting urban environmental evaluation and design practice, for example to facilitate estimation of significant impacts such as greenhouse gas emissions. It is concluded that linking a service (in this case, teaching students) enabled by a given product (university buildings) to the amount of materials used in creating that product offers a potential way to reduce the environmental impact of that service, through more efficient use of materials.
Keywords: Construction materials, material flow analysis, urban metabolism, urban structural unit.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17172515 Analyses of Natural Convection Heat Transfer from a Heated Cylinder Mounted in Vertical Duct
Authors: H. Bhowmik, A. Faisal, Ahmed Al Yaarubi, Nabil Al Alawi
Abstract:
Experiments are conducted to analyze the steady-state and the power-on transient natural convection heat transfer from a horizontal cylinder mounted in a vertical up flow circular duct. The heat flux ranges from 177 W/m2 to 2426 W/m2 and the Rayleigh number ranges from 1×104 to 4.35×104. For natural air flow and constant heat flux condition, the effects of heat transfer around the cylinder under steady-state condition are investigated. The steady-state results compare favorably with that of the available data. The effects of transient heat transfer data on different angular position of the thermocouple (0o, 90o, 180o) are also reported. It is observed that the transient heat transfer around the cylinder is strongly affected by the position of thermocouples. In the transient region, the rate of heat transfer obtained at 90o and 180o are higher than that of stagnation point (0o). Finally, the dependence of the average Nusselt number on Rayleigh number for steady and transient natural convection heat transfer are analyzed, and a correlation equation is presented.
Keywords: Steady-state, transient, natural convection, Rayleigh number, Nusselt number, Fourier Number.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1220