volume-11-Issue 1 (2016)
Latest Articles
Numerical Modelling of Sonicated, Continuous Transesterification and Evaluation of Reaction Kinetics for Optimizing Biodiesel Reactor Design
IJTEE, volume-11, Issue 1 (2016) , PP 79 - 86
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.012
by Mohammed Noorul Hussain, Tala el Samad, Mohammed Daqaq, Isam Janajreh from Masdar Institute of Science and Technology, Abu Dhabi, UAE, 54224
Abstract: Biodiesel is an alternative and sustainable fuel that can reduce the dependence on fossil diesel. This commodity has not only been promoted in the developed world but also in Indonesia, Brazil, and several developing counties. In a general procedure, it is a product of a transesterification reaction of vegetable oils or wastes cooking oils with alcohol, in the presence of an acidic or basic catalyst. It is a slow reaction that is conventionally carried out in a mechanically stirred batch process. An advanced method to achieve high yield quality in less time is the sonication of the reaction in an integrated continuous process. Sonication causes micro-cavitation in the reactant mixture. The cavitation bubbles can have an internal pressure and temperature as high as 1000 atm and 5000K, respectively. The violent collapse of these bubbles causes a tremendous increase in mass transfer, thereby enhancing the reaction rates [1]. To optimize the design of the reactor, high fidelity modeling-assisted design is pursued. This enables the effective integration of the reactant transport and the sonication effect in a coupled acoustic, reactive multiple-specie flow. In this work, a cylindrical reactor is considered in which reactant mixture will be circulated and sonicated by a sonotrode type ultrasound equipment. To simulate the sonication effect the linear, time-independent wave equation is solved for the fluid domain, which provides us with the acoustic pressure variation in the fluid. To account for the attenuation of the wave due to cavitation bubbles the modified wave number is used. To account for the chemical reactions, laminar reacting flow is assumed for the reactant mixture for which the Navier-Stokes equations and transport equation for dilute species are solved for the fluid. A logical reaction rate coupling model, which is dependent on the acoustic pressure and flow velocity, is used to evaluate the kinetics of the reaction, which are to be used as a judging factor for the reactor design [2]. read more... read less...
Keywords: : Transesterification, ultrasound, biodiesel, process intensification, numerical modelling
On the Modeling of Industrial Furnaces and Combustion Chambers
IJTEE, volume-11, Issue 1 (2016) , PP 73 - 83
Published: 19 Dec 2016
DOI: 10.5383/ijtee.12.01.010
by Essam E Khalil from Professor of Mechanical Engineering , Fellow AIAA, Fellow ASME, Fellow ASHRAE, Cairo, Egypt
Abstract: The recent advances in numerical methods and the vast development of computers had directed the designers to better development and modifications to airflow patterns and heat transfer in furnaces. Extensive efforts are exerted to adequately predict the heat transfer characteristics in the combustor zones and to reduce the emitted pollution and noise abatement to ultimately produce quiet and energy-efficient combustor systems. The present paper introduces a newly developed Computational Fluid Dynamics (CFD) program (3DTCFD) to predict the airflow characteristics in the furnaces. The present paper fosters mathematical modeling techniques to primarily predict what happens in three-dimensional combustion chambers simulating boiler and industrial furnaces in terms of heat transfer characteristics and interactions. The present work also demonstrates the effect of chamber design and operational parameters on performance under various operating parameters. The governing equations of mass, momentum, and energy are commonly expressed in a preset form with source terms to represent pressure gradients, turbulence, and heat transfer. Fluid flow and heat transfer characteristics in combustors play an important role in efficiency, thermal balance, and performance. The present paper discusses the various modeling assumptions in furnaces. The present paper discusses the various combustion modeling assumptions in furnaces. The numerical grid comprises; typically, 200000-grid nodes covering the combustion chamber volume in the X, R, or Y and Z coordinate directions. The numerical residual in the governing equations typically less than 0.001 %. Examples of the large industrial furnaces are shown in the present paper are in good agreement with available measurements in the open literature. The present modeling capabilities are shown to adequately predict the local flow pattern and turbulence kinetic energy levels in complex furnaces. read more... read less...
Keywords: : CFD, Combustion Modelling, Furnaces
Evaluation of Solar Hybrid Power Systems and its Efficacy in the UAE Market
IJTEE, volume-11, Issue 1 (2016) , PP 73 - 78
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.011
by Zaki Iqbal, and Gorkem Soyumer from RAK Research and Innovation Center, American University of Ras Al Khaimah, UAE Enerwhere Sustainable Energy, Dubai, UAE
Abstract: Due to rapid industrialization and urbanization, the supplying of the electricity demand using hybrid (solar and diesel) systems have attracted great interest in UAE [1]. In this paper, comparisons of electricity generation with three configurations have been studied, starting from the base scenario of i) multiple stand-alone hybrid systems which are upgraded to ii) AC-coupled mini-grid and iii) DC-coupled mini-grid. The available energy supply, storage, and transmission units as well as internal electrical demand of RAKRIC’s open-air R&D laboratory, Solar, have constituted the basis of the calculations. The cost estimates for the major components forming mini-grids have been found out to be comparable for AC-coupled and DC-coupled networks. Although the results provided in this paper do not apply universally since the feasibility of electricity transmission and storage is notably affected by the positions of supply and load centers along with the generation and consumption time profiles. The solar hybrid power system can be the next option for the UAE fast-growing market. read more... read less...
Keywords: Hybrid Electricity, AC Coupled, DC Coupled, Stand-Alone Off-Grid, Homer
Fe-Cu Compounds in Dye-Sensitized Solar Cells: Influence of Magnetic Field on Mesoporous Structure
IJTEE, volume-11, Issue 1 (2016) , PP 67 - 72
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.010
by Abdul Hai Alami, Di Zhang, Camilia Aokal, Jehad Abed, Ideisan Abu Abdoun, Hussain Alawadhid from Sustainable and Renewable Energy Engineering Department, University of Sharjah, P.O.Box 27272m Sharjah, UAE Masdar Institute of Technology, Abu Dhabi, United Arab Emirates Department of Chemistry, University of Sharjah, P.O.Box 27272m Sharjah, United Arab Emirates d Applied Physics Department, University of Sharjah, P.O.Box 27272m Sharjah, United Arab Emirates
Abstract: This paper investigates the effect of applying a static and dynamic magnetic field in the process of depositing the Fe-Cu compound on the working electrode of a dye-sensitized solar cell (DSSC). Depositing this compound on glass is especially hard due to the unfavorable layer inconsistencies that accompany the utilization of the doctor blade technique and the dissociation of the compound at a temperature of 700˚C, which prevents its ability to be evaporated or sintered beyond that temperature. The Fe-Cu compound is appreciably cheaper, relatively simple to produce, and is more absorptive (>81%) in the Vis-NIR than the standard TiO2 mesoporous material normally used for DSSCs. The high diffusion of the Fe into the Cu lattice allows the compound to behave as a semiconductor and is found to have a bandgap of 1.8V. The sensitizer used in the production of a test cell consisted of a Schiff base dye with a compatible bandgap of 1.68 eV and resulted in more generated photocurrent than its TiO2 counterpart, which is a promising result for an alternative mesoporous layer in solar cells. read more... read less...
Keywords: Ferromagnetic Mesoporous Material, Dye-sensitized Solar Cells, Schiff Base Dyes
Energy Savings Potential Associated with Reactive Power in Water Pumping Systems
IJTEE, volume-11, Issue 1 (2016) , PP 61 - 65
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.009
by Abdallah S. Hejab and Ahmad H. Sakhrieh from Head of Technical Studies, Research and Development, Water Authority of Jordan, 5012 Amman 11181, Jordan Department of Mechanical and Industrial Engineering, American University of Ras Al Khaimah, 10021 UAE Mechanical Engineering Department, University of Jordan, Amman 11942, Jordan
Abstract: ]This paper presents the potential of energy saving in the water pumping system. A sample of 32 pumping units has been chosen randomly for the current work. Measurements of power quality energy loss were performed, using Fluke 437-ii power quality and energy analyzer. It was found that energy losses due to reactive power are about 22% of the total power energy losses in water pumping units in Jordan. Losses due to reactive power is 14.57 GWh in 2012 with an expected cost of 51.2 GWh during 2015-2017; unless reactive power is cured read more... read less...
Keywords: Energy Efficiency,Reactive Power,Water Pumping
Design and Investigation into the Thermal and Mechanical Performance of a Polymer Composite Prototype Gas-Liquid Heat Exchanger
IJTEE, volume-11, Issue 1 (2016) , PP 51 - 59
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.008
by Bidisha Ghosh, Wadeema Yousef, Mariam Al Jaberi, Nuha Al Hajeri, Asrar Al Braiki, Valerie Eveloy, and Peter Rodgers from Department of Mechanical Engineering, the Petroleum Institute, Abu Dhabi, United Arab Emirates
Abstract: Seawater-cooled metallic heat exchangers used in natural gas processing are prone to corrosion and fouling, resulting in increased operational and maintenance costs. A lab-scale polymer composite gas-liquid webbed tube bank heat exchanger is designed and evaluated for application in conditions representative of a fielded natural gas processing application. The heat exchanger thermal performance and structural integrity are investigated numerically using computational fluid dynamics (CFD) and finite element (FE) models, respectively. For polymer composite thermal conductivities above 20 W/m-K, in forced gas-side convection, the exchanger heat transfer rate is comparable to that of a high conductivity conventional metallic heat exchanger having the same geometry, at reduced materials, manufacturing, and operational costs. In addition, the prototype heat exchanger would be structurally reliable at the maximum envisaged gas-side operating pressure for the application considered. read more... read less...
Keywords: Polymer, Composite, Heat Exchanger
Nature of Steel Effect on Intermetallic Compounds Obtained by Galvanization,
IJTEE, volume-11, Issue 1 (2016) , PP 47 - 50
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.007
by Younes Benarioua, and Didier Chicot from Département de Génie Mécanique, Faculté de Technologie,Université de M’sila BP 166 Ichbilia 28000 M’sila, Algérie Université Lille Nord de France, Lille1, LML, UMR 8107, F-59650 Villeneuve d’Ascq, France
Abstract: en English Home Online text tools ▼ About project Remove multiple spaces This online tool help you quickly replace multiple (double) spaces in a string to single space, remove all spaces, empty space in the line beginning and line end and delete empty lines in your text. Remove multiple spaces online Paste your text in the textarea below: Zinc and some of its alloys have a number of characteristics that make it well suited for use as a protective coating against the corrosion of steel substrates under severe atmospheric conditions. The metal of zinc, which represents the main galvanization element offer then cathodic protection to the ferrous materials. Because of these excellent characteristics, galvanization coatings are expected to be used for different protective application fields. The objective of this work is to study the influence of the nature of steel substrate on the microstructure and the hardness of the intermetallic compounds. The steels used as the substrate are employed in the agriculture field as tubes and irrigation elements in the pivot. After an optimal preparation of the surface of the substrate by an appropriate roughness process, the steels specimen were immersed in a molten zinc bath maintained at 450°C. The chemical reactions which take place between the steel and the liquid zinc give rise to the formation of the and intermetallic compounds and the -Fe/Zn solid solution. The structure of the coating was identified by X-ray diffraction. The morphology and thickness of phases formed the coatings at different parameters took place with an optical microscope. Finally, the hardness of coatings was measured with a Vickers hardness tester. Your text without multiple spaces: Zinc and some of its alloys have a number of characteristics that make it well suited for use as a protective coating against the corrosion of steel substrates under severe atmospheric conditions. The metal of zinc, which represents the main galvanization element offer then cathodic protection to the ferrous materials. Because of these excellent characteristics, galvanization coatings are expected to be used for different protective application fields. The objective of this work is to study the influence of the nature of steel substrate on the microstructure and the hardness of the intermetallic compounds. The steels used as the substrate are employed in the agriculture field as tubes and irrigation elements in the pivot. After an optimal preparation of the surface of the substrate by an appropriate roughness process, the steels specimen were immersed in a molten zinc bath maintained at 450°C. The chemical reactions which take place between the steel and the liquid zinc give rise to the formation of the and intermetallic compounds and the -Fe/Zn solid solution. The structure of the coating was identified by X-ray diffraction. The morphology and thickness of phases formed the coatings at different parameters took place with an optical microscope. Finally, the hardness of coatings was measured with a Vickers hardness tester. Remove multiple spaces options Replace multiple spaces to single space Replace multiple spaces to double space Remove all spaces Remove Spaces and Tab in the lines beginning Remove Spaces and Tab in the lines end Remove empty lines Popular online tools Remove Line Breaks Text to Html Letter Case Converter Remove Multiple Spaces Flip Text - ʇxǝʇ dıןɟ Ⓑⓤⓑⓑⓛⓔ Ⓣⓔⓧⓣ Сolumn to Separated List Additional information Remove Double Spaces with Delphi Remove Double Spaces with C# Remove Double Spaces with Javascript Remove Double Spaces with PHP © 2010-2021 Dovzhyk Mykhailo support@texthandler.com Online tool that remove multiple (double) spaces, empty space in the lines beginning and lines end and delete empty lines. Texthandler - online text tools read more... read less...
Keywords: Steel, Zinc, Iron, Galvanization.
Performance of World Health Organization as a Green Building
IJTEE, volume-11, Issue 1 (2016) , PP 41 - 46
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.006
by K. Hassouneha, A. Al-Salaymeh, and A. Sakhrieh from Architecture Engineering Dept., Faculty of Engineering & Technology, The University of Jordan, Amman, Jordan Mechanical Engineering Dept., Faculty of Engineering & Technology, The University of Jordan, Amman, Jordan Department of Mechanical and Industrial Engineering, American University of Ras Al Khaimah, UAE
Abstract: The rapidly growing world energy use has already raised concerns over supply difficulties, exhaustion of energy resources, and heavy environmental impacts. The global contribution from buildings towards energy consumption has steadily increased. Jordan relying on importing more than (97%) of its oil needs. The household in Jordan consumes 43% of the total electricity produced. The current situation enforces us to have more efficient use of energy in this sector. For this reason, energy efficiency in buildings is today a prime objective for energy policy at the national and international levels. The Jordanian building codes such as the Jordan green building code were developed to face energy challenges that Jordan has recently encountered. In the residential sector, energy is used for equipment and appliances that provide heating, cooling, lighting, water heating, and other household demands. In this study, an efficient energy building has been selected and studied. The present study concentrates on one of the energy-saving examples, which is the Green building represented in the World Health Organization (WHO) building in Amman. A comprehensive study of energy consumption in the building has been carried out. A comparison between the Jordanian regular buildings and the current building was made; EnergyPlus was used to make all calculations. It is found that the WHO building saves 23.9% of the total energy saved from HVAC systems, and widely dependent on natural lighting. WHO reduces the Greenhouse gas emissions of CO2, about 57563.12 kg of CO2 were reduced, which helps in the global warming. read more... read less...
Keywords: rapidly growing, world health organization, green building
Simulation and Economic Analysis of Solar Thermal Cogeneration System for Production of Heat and Pure Water using Membrane Distillation
IJTEE, volume-11, Issue 1 (2016) , PP 33 - 39
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.005
by Uday Kumar N.T, Andrew Martin from RAK Research and Innovation Center, American University of Ras Al Khaimah, Ras Al Khaimah, UAE Department of Energy Technology, KTH Royal Institute of Technology, Stockholm, Sweden
Abstract: In this paper, a novel solar thermal cogeneration (termed as solar combi MD; SCMD) system for production of clean water and domestic hot water is modeled and analyzed for the weather conditions of the United Arab Emirates (UAE). The system comprises solar collectors for the production of thermal energy, thermal storage for domestic hot water generation, and membrane distillation (MD) modules for clean water production gaining energy through a plate heat exchanger. The performance of cogeneration is analyzed with two different solar collectors used for domestic heating – flat plate collectors (FPC) and evacuated tube collector (ETC). The system is modeled and dynamically simulated using TRNSYS software for optimization of various design parameters like collectors tilt angle, the mass flow rate through MD loop, thermal store volume, and heat exchanger effectiveness. Cogeneration system efficiencies and collector areas have been determined for optimum conditions. Economic benefits are analyzed for FPC collectors and fuel costs savings compared to individual system operations. The total investment cost of the SCMD system for single-family applications would be around 5000$ with an impressive payback period of 5.5 years which is 30% lower than regular SDHW installations. read more... read less...
Keywords: Solar Domestic Hot Water, Cogeneration, Membrane Distillation, TRNSYS, Thermal Storage
Validation of Solid Oxide Fuel Cell Thermodynamic Models for System-level Integration
IJTEE, volume-11, Issue 1 (2016) , PP 25 - 32
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.004
by Valerie Eveloy, Wirinya Karunkeyoon, Peter Rodgers, Ali Al Alili from Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi, United Arab Emirates
Abstract: The accurate computational modeling of fuel cells is challenged by the complexity of fuel cell multi-physics, and the difficulty in finding comprehensively documented reference data for model validation. Three published experimental/numerical solid oxide fuel cell (SOFC) configurations suitable for model validation are identified, the SOFC modeling and performance data of which is compiled from several sources. The configurations combine different cell constructions and operating conditions, in terms of fuel composition, fuel conversion, operating temperature, and pressure, as well as different SOFC model formulations. A system-level SOFC model is developed and validated based on the reference data compiled. Overall, good agreement is found between the present SOFC model predictions and the corresponding reference experimental/numerical data. read more... read less...
Keywords: Solid Oxide Fuel Cell, Modeling, System Level, Validation
Micro Gasturbine Integrated Design. Part 2: Compressor and Turbine
IJTEE, volume-11, Issue 1 (2016) , PP 15 - 24
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.003
by Dario Barsi, Tiziano Garbarino, Andrea Perrone, Luca Ratto, Gianluca Ricci, Fabrizio Stefani, Pietro Zunino from DIME – University of Genova, Via Montallegro 1, 16145, Genova, Italy
Abstract: Multidisciplinary design optimization (MDO) is widely employed to enhance turbomachinery component's efficiency. The aim of this work is to describe a complete tool for the aero-mechanical design of a radial inflow turbine and a centrifugal compressor. The high rotational speed of such machines and the high exhaust gas temperature (for the turbine) exposes blades to really high stresses and therefore the aerodynamics design has to be coupled with the mechanical one through an integrated procedure. This approach employs a fully 3D Reynolds Averaged Navier-Stokes (RANS) solver for the aerodynamics and an open-source Finite Element Analysis ( ) solver for the mechanical integrity assessment. Due to the high computational cost of both these two solvers, a metamodel, such as an artificial neural network, is employed to speed up the process. The interaction between two codes, the mesh generation, and the post-processing of the results are achieved via in-house developed scripting modules. The obtained results are widely presented and discussed. read more... read less...
Keywords: Cogeneration, Centrifugal Compressor, Radial Turbine, MicroGT
Micro Gasturbine Integrated Design. Part 1: Thermodynamic Cycle, Combustor, Recuperator and Bearings
IJTEE, volume-11, Issue 1 (2016) , PP 5 - 14
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.002
by Dario Barsi, Tiziano Garbarino, Andrea Perrone, Luca Ratto, Gianluca Ricci, Fabrizio Stefani, Pietro Zunino from DIME – University of Genova, Via Montallegro 1, 16145, Genova, Italy
Abstract: In the last years, micro gas turbines for cogeneration power plants have been proved to be a promising technical solution for the distributed production of electricity and heat. In order to enhance the machine efficiency and make it competitive with internal combustion engines, it is necessary to improve the efficiency of each component of the GT: in the first part of the paper, the focus will be put on the combustor, the recuperator, and the bearings. Combustor and bearings are cutting-edge technology and for them, a brief description of the design procedure has been reported. The recuperator plays a key role in the cycle efficiency since the reduction of the pinch point temperature difference can strongly enhance the overall efficiency, read more... read less...
Keywords: Cogeneration, Bearings, Combustor, Recuperator
Structural Optimization of Solar Driven Energy and Desalination Systems
IJTEE, volume-11, Issue 1 (2016) , PP 1 - 4
Published: 19 Dec 2016
DOI: 10.5383/ijtee.11.01.001
by Stefan Kirschbaum, Julian Agudelo, Gregor Wrobel, Franziska Blauth, Rizka D.A. Kölsch from Graphical Engineering Systems, Society for the Promotion of Applied Computer Science (GFaI e.V.), Berlin, Germany Institut für Energie- und Umwelttechnik (IUTA e.V.), Duisburg, Germany
Abstract: Planning and dimensioning of desalination plants is usually done by engineers based on an estimation of the capacity of makeup water that is needed for a certain site. Planning a solar-powered system of water and energy supply is complicated and requires a lot of experience from the executing engineer. Optimization methods can support the process of planning complex energy and water supply systems in many ways. Structural optimization is a way to determine an optimized size and configuration for a given task. In this paper, a methodology is presented that allows for structural optimization of energy and water supply systems with a focus on a high share of solar energy use. The methodology has been implemented using a software framework that contains functionality for modeling, simulating, optimizing, and analyzing energy and water supply systems. Based on load profiles for energy and water as well as technical and economical parameters of the components, a linear optimization is carried out in order to calculate an optimized structure of the system. Furthermore, the optimization calculates the capacities of the desalination and energy conversion components and an optimized mode of operation depending on the primary energy prices and solar yield. The methodology uses a MILP algorithm to solve the optimization problem based on linear component models. The linear optimization is coupled with an algebraic equation solver to allow solving of nonlinear equations as well, thus forming a hybrid simulation and optimization algorithm. read more... read less...
Keywords: structure, solar energy, desalination