bluuebunny/crossref_metadata_2025 huggingface dataset:
Studying Electrical Engineering and Information Technology at the University of Split, Croatia
Authors: Kilić T. , Puljak I. , Begušić D.
Published: February 2013

The Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture (FESB) of the University of Split was founded in 1960. A nine-semester study programme in electrical engineering has been continuously offered ever since with specialisation in several fields. Since the academic year 2005/2006 a new study programme of electrical engineering and information technology has been introduced fully in accordance with the Bologna Declaration. All three cycles, Bachelors, Masters and Doctoral, have been set up. Currently a second year of Bachelor programme students and a first year of Doctoral programme students are attending courses and are participating in all study activities. The prevailing experiences with the implementation of the Bologna Declaration are so far quite positive, and we look forward to completing all cycles.
Bologna and the MEng: ‘Sleepwalking into Unknown and Unpredictable Territory’
Authors: Neal-Sturgess Clive
Published: February 2013

The background to the Bologna process is that there was considerable concern in the 1990s at governmental level in the EU nation states over economically unsustainable, grossly inefficient higher education systems. The Bologna process of three cycles of higher education, the first being the ‘mobility degree’ (Bachelors level) after three years of study, the second (Masters level) after a further two years of study, and a third cycle of postgraduate study as yet undefined, has received widespread agreement across now 45 nation states, and has gained worldwide interest. For certain sections of UK higher education, such as engineering, science, architecture and medicine, where the degree cycles do not fit with the Bologna cycles, the Bologna process presents significant diffiulties. This paper explores those difficulties, and possible responses, none of which are themselves without difficulty.
The Impact of Bologna on Engineering Studies: Comments on the Spanish Case
Authors: de Cuadra García Fernando
Published: February 2013

This paper presents the current status of engineering studies in Spain, including the structure and professional profile of the existing degrees, and all the specific circumstances — social, legal and political — that complete the scenario. The impact of Bologna on this scenario is still uncertain, but in this paper the two main options — ‘smooth evolution’ and ‘deep revolution’ — are described and analysed.
Engineering Education at the Association K.U. Leuven: A Changing Higher Education Landscape
Authors: Loosvelt Hugo , Gysen Marleen , Belmans Ronnie , Baert Frank
Published: February 2013

The implementation of the Bachelor-Master structure has had a deep impact on the organisation of education in Flanders. Students obtain a Bachelors degree after three years of study and a Masters degree after at least one additional year. The former three year programmes at a hogeschool are converted into profession-oriented Bachelors programmes; the former two cycle programmes at hogescholen and universities are converted into academic Bachelors programmes followed by a Masters programme. Furthermore, all programmes must obtain accreditation. Similar quality standards become valid for programmes offered by hogescholen and universities. While these minimum standards do not imply identical educational training, the concern arose that differentiation of engineering education would tend to fade or disappear. Therefore, it is essential to have a clear description of the different profiles of engineering professionals. An overview of the Bachelors and Masters engineering programmes at the Association K.U. Leuven is presented.
Levitation of an Aluminium Disc in a Magnetic Flux Well
Authors: Barry N. , Hudgins J.
Published: February 2013

An aluminium disc is levitated above a two-coil arrangement in a magnetic flux well, in a low voltage and wattage implementation. A coupled circuit analysis of the system allows an estimate of the lifting force.
Integration into Undergraduate Courses of Transformer Tests Using MATLAB/Simulink
Authors: Zobaa A. F. , Boghdady T. A.
Published: February 2013

This paper is concerned with determining the element parameters of the equivalent circuit model of the transformer. Short circuit, open circuit and load circuit tests will be applied to determine these parameters. The viability of the model can then be checked against the results of a load test. Efficiency and voltage regulation can then be determined from the data. These simulation models are developed to support and enhance electric machinery education at the undergraduate level.
Efficient Approach to Determine the Steady-State Energy in Networks with Periodic Discontinuous Excitations
Authors: Trzaska Z. W.
Published: February 2013

A new method for the solution of non-sinusoidal periodic states in linear networks is presented. It avoids the Fourier series calculations of the input and output network quantities. In the proposed method, the steady-state network response is formulated directly in the time domain as a superposition of the zero-input and forced responses for each continuous piecewise segments of the input quantity, separately. The whole periodic response is reached by taking into account the continuity and periodicity conditions at instants of discontinuities of the input quantity and then using the concatenation procedure for all segments. The method can be applied efficiently to continuous and discontinuous input quantities equally well. When we divide the network into two parts, i.e. a supplying two-terminal source and a two-terminal load, this method can be applied more efficiently to determine one-period energy for each of these particular subnetworks. Solutions are exact and there is no need to apply any of the widely up-to-date used frequency approaches. The Fourier series is completely cut out of the network analysis.
Four Case Studies of Adapting Enquiry-Based Learning (EBL) in Electrical and Electronic Engineering
Authors: Powell Norman J. , Hicks Peter J. , Truscott William S. , Green Peter R. , Peaker Anthony R. , Renfrew Alasdair , Canavan Brian
Published: February 2013

Four different instances of enquiry-based learning (EBL), developed in a School of Electrical and Electronic Engineering, are described. Key decisions in the design of these activities are detailed, emphasising flexibility in approach. Although the activities took place in broadly the same environment, the local contexts required subtle tailoring. The design decisions taken in each case are described and general overviews from integrative evaluations are provided. An emergent distinction between the forms of EBL developed was between those that focused on generic or specific skills and those that focused on content knowledge; these may be termed project-based learning and problem-based learning respectively. The influence of the focus of the activity on the design decisions is described.
Electrical Measurements Student Laboratory — Replacing Hands-on with Remote and Virtual Experiments
Authors: Malarić Roman , Jurčević Marko , Hegeduš Hrvoje , Cmuk Drago , Mostarac Petar
Published: February 2013

This paper discusses the problem of transferring knowledge to students of an undergraduate electrical measurement course, and also describes the design of a Web-based measurement laboratory and experimental setup of Web-based experiments at the Faculty of Electrical Engineering and Computing (FER) in Zagreb, Croatia. The suggested design offers the possibility of teaching or presenting high-precision experiments using expensive or sensitive equipment that is unavailable in sufficient quantities to serve large numbers of students.
Three-Phase Transformer and Voltage Regulator Modelling for Forward/Backward Sweep-Based Distribution System Power Flow Algorithms
Authors: Eminoglu Ulas , Hocaoglu M. Hakan
Published: February 2013

This paper describes a new approach for modelling of a distribution transformer and automatic voltage regulator in forward/backward sweep-based algorithms for unbalanced radial distribution systems. For the transformer modelling a symmetrical components model is used and zero sequence voltage and current updating for the sweep-based methods are demonstrated. The validity and effectiveness of the proposed method is demonstrated in a simple two-bus system for grounded wye-delta and delta-grounded wye transformer connections. The automatic voltage regulators (AVRs) are included into the sweep-based methods and tested by using two distribution test systems. From the systems, all results are in agreement, the proposed model is valid and reliable, and the performance of the algorithms is less affected from the inclusion of regulator modelling.
A Practical Approach to Introducing Electrical Undergraduates to Artificial Neural Networks
Authors: Halkiadis I. S.
Published: February 2013

Artificial intelligence techniques are increasingly being applied to a variety of problems in the field of electrical engineering, and consequently universities worldwide are paying more attention to training electrical engineers in applying neural networks (ANNs) in practice. As part of the above training, an introductory practical project on ANNs has been offered as an elective to the undergraduates in the author's department. The project introduces a single layer ANN model consisting of two neurons. The algorithm, the hardware implementation and the test procedure concerning one of the neurons, are described. Then the students apply the same techniques for the other neuron and combine the two circuits to form the final ANN hardware. The agreement of the results conducted by the theoretical models with those obtained by the constructed circuits, allow the students to become familiar with ANN hardware techniques and realise that they present a practical and efficient solution.
Enhancing the Teaching of Professional Practice and Key Skills in Engineering through the Use of Computer Animation
Authors: McMenemy Karen , Ferguson Stuart
Published: February 2013

This paper presents some observations on how computer animation was used in the early years of a degree program in Electrical and Electronic Engineering to enhance the teaching of key skills and professional practice. This paper presents the results from two case studies. First, in a first year course which seeks to teach students how to manage and report on group projects in a professional way. Secondly, in a technical course on virtual reality, where the students are asked to use computer animation in a way that subliminally coerces them to come to terms with the fine detail of the mathematical principles that underlie 3D graphics, geometry, etc. as well as the most significant principles of computer architecture and software engineering. In addition, the findings reveal that by including a significant element of self and peer review processes into the assessment procedure students became more engaged with the course and achieved a deeper level of comprehension of the material in the course.
A New Low-Cost DSP Educational Tool for a Laboratory for Motor Control
Authors: Montesinos-Miracle Daniel , Galceran-Arellano Samuel , Sudrià-Andreu Antoni , Gomis-Bellmunt Oriol
Published: February 2013

There has been an increasing use of modern digital signal processors (DSPs) in industrial control and other applications in the past few years. While courses offered in electrical and computer engineering disciplines cover such topics as mobile and digital communication, image and sound encoding and decoding, few courses focus on the use of DSPs in real-time control of electrical machinery and drives. Therefore, there is a growing need in industry for engineers who can perform control design and system integration for various applications in motor control. This paper describes a course on Control of Electrical Machines offered by the School of Industrial Engineering of Barcelona (ETSEIB), Polytechnic University of Catalonia (UPC), Barcelona, Spain. A description of a hands-on laboratory testbed for motor control.

An outline of the course structure, the laboratory setup and the design aspects for implementing modern real-time motor control applications are presented.
WNetSim: A Web-Based Computer Network Simulator
Authors: Jovanovic N. , Popovic R. , Jovanovic Z.
Published: February 2013

This paper describes a web-based computer network simulator. The system is realised in Java programming language and can be executed as a standalone Java application or Java applet. The environment enables process visualisation and simulation in computer networks with arbitrary topology. Physical and logical IP addressing of computers and router interfaces are supported, as well as working with sub-networks. Routers enable static packet routing, importing static routes in the configuration procedure. Components are configured using configuring dialogue (standard Windows dialogue), or using a line command interface. The processes of forming, addressing, sending, transferring and receiving of frames are visualised, where functions of network devices such as hub, switch and router, are explained. The system enables the creation of many laboratory exercises, which offer students opportunities to follow visually characteristic processes in computer networks. Web-based technology enables the computer network simulator to be used in distance learning.
Power Quality-Based Classification and Modelling of Small Loads and Generators
Authors: Mujović Saša , Katić Vladimir , Radović Jadranka
Published: February 2013

The paper presents an overview of existing methods of classification of small loads and generators, giving a new approach to this issue. This new approach divides loads according to their consumed current-time waveform distortion and generators according to generated output voltage wave shape, i.e. power quality issues. For each of the selected categories an adequate mathematical (mathematical relation) and computer simulation model has been developed. The model is verified by results of laboratory measurements. The proposed approach is more suitable for practical application than previously proposed classifications as it facilitates obtaining information about the level of higher harmonics, without knowledge of the internal device structure. Further, it can be easily applied in practical laboratory setups to facilitate teaching at both undergraduate and postgraduate levels.
Social Interactions in Collaborative Problem-Solving in a Teaching Experiment Involving a Micro-Chip
Authors: Yang Hung-Jen , Yu Jui-Chen , Wang Chang-Chung
Published: February 2013

We investigated collaborative problem solving in a teaching experiment organized for 32 university sophomores in a computing environment. The participating teacher was trained by us and students were supplied with kits, interfaces and computers equipped with programming tools for a 8051 micro-chip. Student activities were video-recorded and the analysis proceeded through writing video-protocols, editing into episodes and then classification into categories. The data show that typical learning processes were collaborative (51% of all episodes). Students worked quite independently of the teacher, as they learned to use the programming tool autonomously in their projects. It appears, however, that more teacher support, such as introducing handbooks, planning tools and advanced programming skills, would have been an advantage, and non-group interactions would provide more help in the problem-solving process. Some ideas for the further development of study procedures in modern learning environments are discussed.
Rules for Determining the State of a Bipolar Junction Transistor
Authors: Cassara Frank A.
Published: February 2013

In pulse and digital electronics the bipolar junction transistor (BJT) may be in saturation, cut-off, active, or reverse (inverse) active states. In addition, the BJT may change states as voltages and currents change with time. Analysis and design can often become challenging and frustrating for the undergraduate student who has not yet developed intuitive insight into the subject matter. In this paper logical and systematic rules for determining the state of a BJT are presented to simplify the circuit analysis, ease the frustration, and help the student develop physical insight into the design and analysis of electronic circuits.
Facilitating Social Networking within the Student Experience
Authors: Clafferty Elaine Margaret
Published: February 2013

Informed by a mature research base on what enhances the student experience, knowledge of the nature of the contemporary student and advances in technology and internet use, we can explore the potential to further evolve socialisation as part of the student experience. This paper reports on the evaluation and introduction of what has become known as ‘online social networking’ as one of the ways in which students can become ‘socialised’ within their university environment. The aim was to provide an educationally focused online social networking environment that is serious in its purpose and objectives, but which retains the user attractiveness of the major general purpose social networking systems. The range of technology options available is discussed and conclusions are drawn which indicate that a successful form of educational online social networking can be established with very simple technology.
3D Virtual Classroom Environment for Teaching Renewable Energy Production and Substation Equipment
Authors: Aydogan Hakan , Karakas Ercument , Aras Faruk , Ozudogru Fatma
Published: February 2013

In this investigation, a virtual classroom for Uşak University's Electricity Program is designed, implemented and then tested by using the 3D virtual environment Second Life. When online, learners and instructors are able to correspond with each other by using their own avatars, chat vocally, make presentations and watch videos, as well as utilise all opportunities of a 3D virtual environment. Furthermore, learners can access the educational materials of the Electricity Program and interact with each other even when the educator is not available, giving opportunities for both synchronous and asynchronous distance education. The 3D virtual environment is analysed and evaluated here in terms of education costs, and advantages or disadvantages for both learner and educator.
A Comparison of MCQ Assessment Delivery Methods for Student Engagement and Interaction Used as an in-Class Formative Assessment
Authors: Chan Cecilia Ka Yuk , Tam Vincent W. L. , Li Chi Ying Vanessa
Published: February 2013

Student interaction and formative assessment are two agendas which hold equal importance in guiding the student approach to learning in engineering and in many disciplines. With MCQs being a familiar assessment tool for most teachers, it would be ideal if there were a combined approach which involved using MCQ to assess formatively and at the same time, to encourage student engagement and in-class interaction. In this paper, we investigate a number of MCQ delivery methods which may be able to step up to both concerns.
A Platform-Independent Learning Tool for Power System Analysis Concepts
Authors: Omer Mohamed , Idowu Peter B.
Published: February 2013

A software visualization tool is developed to help in teaching core power systems analysis problems in introductory undergraduate courses. The power system analysis concepts visualization tool consists of simulation applications that focus on three problems: load flow, economic dispatch, and unit commitment. It incorporates user-friendly effective graphical interfaces that aid students in acquiring deeper understanding of the power system problems and developing the analytical skills needed in industry. The learning tools are implemented in C# language for platform-independence to increase accessibility. Evaluation of the visualization tool shows very encouraging results.
Teaching Calculation of Inductance of Power Transmission Lines
Authors: Krishna S.
Published: February 2013

The conventional derivation of the expression for inductance of power transmission lines given in books is more a recipe than a derivation starting from a law of physics. The serious shortcomings of the traditional approach are that the definition of flux linkage lacks strong connection to Faraday's law, and unnecessary assumptions are made. This paper gives a complete rigorous derivation of the expression for inductance of power transmission lines. This paper will help instructors as well as students, since it addresses the deficiencies present in the derivation given in textbooks.
Software Tool for Evaluation of Electrical Energy Produced by Photovoltaic Systems
Authors: Dobrić Goran , Durišić Željko , Stojković Zlatan
Published: February 2013

This paper presents a software tool for evaluation of electrical energy generated by photovoltaic (PV) systems. The software was developed using the MATLAB software package and contains the elements of an expert system. The software is designed for engineers who are involved in photovoltaic system design and for students (undergraduates and Masters) of electrical engineering who, using the software, adopt theoretical assumptions and solve practical engineering problems. The structure, organization and software capabilities are illustrated within the example of the design of an actual photovoltaic system.
From Mathematical Analysis to Experimental Calculation: Teaching Three-Phase Short-Circuits of a Synchronous Generator
Authors: Wang J. X. , Zobaa A. F. , Bie Z. H. , Xia D. Z.
Published: February 2013

Besides highlighting the physical model in electrical engineering curricula, the mathematical model should also be emphasised. Mathematical derivation can clearly show students how to obtain the conclusions from the original equations, and how to simplify the complex theories to the experimental equations. This paper uses the three-phase short-circuit calculations of a synchronous generator to demonstrate the evolution from mathematical theory to practical application. From various expressions in a typical example, the students can learn to analyse the same problem in different situations. This will help them to master the analytical method from mathematical theory to electrical engineering application.
Engineering Mathematics Teaching via the TI-92 Part I: Enhancing Basic Skills
Authors: Short L.
Published: February 2013

We discuss the use of the TI-92 ‘Supercalculator’ in enhancing the teaching and learning of first-year ‘engineering mathematics’. Several illustrative examples are discussed which highlight some of the essential features of the technology, and which can be used to develop basic mathematical skills. In addition some of the educational implications of the existence of such powerful hand-held technology is considered.
Dimensional Analysis of Synovial Joints
Authors: Hale R. D. , Sharp J. J.
Published: February 2013

Prior to undertaking experiments or developing a mathematical model of a complex phenomenon it is necessary to do some preliminary work in an attempt to gain some understanding of the physics involved and to identify the relevant parameters. Although usually thought of as a tool for physical modelling, dimensional analysis really provides a basic framework for thinking about a problem and this is useful whether the end result is intended to be a physical or a mathematical model. Students of complex systems would thus be well advised to begin with a partial analysis with the intention of obtaining some fundamental understanding of the phenomenon under consideration. Identification of the variables involved leads to the development of functional equations and a set, or sets, of dimensionless parameters. These parameters provide the modeller with a guide to the parameters which might appear, separately or in combination, in any complete solution. In many cases, a complex system may be usefully broken down into a number of subsystems each of which may be treated separately, but with the outputs from some subsystems (the dependent parameters) being the inputs (the independent parameters) to other subsystems or to the main system.

The example given here refers to a study of joints of the human body where dimensional analysis was used as a preliminary tool in a larger investigation designed to lead eventually to a finite element model. The paper attempts to show how such an analysis can be helpful: (1) in thinking about the problem; (2) in identifying the dimensionless parameters which provide a potential framework for a more complete solution; and (3) in breaking down a very complex problem into a number of related subsystems which can be more easily solved.
Approximate Solutions of Differential Equations Using Galerkin's Method and Weighted Residuals
Authors: Petrolito J.
Published: February 2013

The usual textbook approach to Galerkin's method can be misleading, and fails to highlight all the possible errors that arise in an approximation scheme. A general weighted residual is presented that explicitly excludes all possible errors. Thus all the inherent approximations are made transparent to students. The conventional form of Galerkin's method is shown to be just one particular case of this method.
Free Vibration Studies Using Galerkin's Finite Element Method
Authors: Krishnan A. , George Geetha
Published: February 2013

An effort is made to formulate systematically the finite element method based on Galerkin's principle to solve beam problems. The developed code is used to study the free vibration characteristics of stepped, spring supported and twisted beams of solid sections. Thin walled sections exhibiting bending twisting coupling (channel) and beams with unsymmetric cross section (Z section) are also analysed. Results obtained with two elements are very reasonable.
Regular Polygonal Shapes, and Boundary Collocation Method
Authors: Kolodziej J. A. , Uścilowska A.
Published: February 2013

In this article, the application of boundary collocation method for solving of boundary value technical problems for domains with regular polygonal shapes is discussed. Two sample problems are considered: (a) steady laminar flow in regular polygonal conduits, and (b) temperature field for hollow prismatic cylinders bounded by isothermal inner circles and outer regular polygon.
Joint-Link Parameter Assignment in Mechanisms and Robotics
Authors: Fischer Ian S.
Published: February 2013

Atlases are developed which aid the student in properly evaluating the joint-link parameters to model the mechanics of mechanisms and robotic systems. Experience in conducting mechanisms and robotics courses has indicated that students often have difficulty in determining these parameters. To assist them, atlases have been developed where the student can find an illustration corresponding to the relationship between coordinate frames on links in the mechanism or robot and then read off the appropriate values of the link twist or joint rotation if that is fixed. The atlases have been developed to include all of the popular coordinate-transformation schemes, 3 × 3 dual-number coordinate transformation matrices for a link and its proximal joint, and 4 × 4 homogeneous transformation matrices for either a link with its proximal joint or a link with its distal joint. Students will find the atlas an aid for correctly assigning joint-link parameters in difficult-to-visualize mechanisms and robotic systems.
A ‘Boundary Layer’ Method for Obtaining an Approximate Equation for the Velocity–Time History of an Accelerating Sphere
Authors: Janna William S. , Nassif Naji
Published: February 2013

A sphere starting from rest in a stationary fluid accelerates under the action of gravity and eventually reaches a terminal velocity. The descriptive equation for the acceleration of the sphere is a first order, non-linear, ordinary differential equation, which can be solved using a finite difference scheme. In this study, we present a method (obtained from boundary layer methods) of generating a velocity—time equation to obtain an alternative solution. The method is used to solve a specific example and the results are compared to those obtained with the numerical solution. The comparison yields a small error, and so the polynomial approximation method can be used as an alternative technique to describing the motion of an accelerating sphere.

The accelerating sphere problem is usually encountered in a study of flow past immersed objects. Boundary layer methods are usually taught at the graduate level. The advantage of the method presented here is that boundary layer methods can be introduced to undergraduates in a first or second course in fluid mechanics.
Unifying the Teaching of Mechanics and of Centrifugal Pump Theory
Authors: Ntoko Nzumbe-Mesape
Published: February 2013

Using the equation of motion of a particle in a rotating co-ordinate system, it is shown that the head developed and the power required by a centrifugal pump are uniquely obtained from centrifugal forces. An expression is then obtained for the optimum outlet blade angle which is used to demonstrate that the phenomenon of slip has a dynamical basis.
The Specific Heats of Gases in an Arbitrary Process
Authors: Chen Jincan , Wu Chih
Published: February 2013

The specific heats of gases in an arbitrary process is investigated and a general expression is obtained. The expression is used to derive the specific heats of ideal and real gases, which are subject to the different equations of state, along an arbitrary path and some specified paths. The results obtained here can give not only the relevant contents in thermodynamics textbooks but also some new useful conclusions, so they are of general theoretical significance and practical application value.
Analytical and Experimental Investigation of the Phenomenon of Self-Locking of Brakes
Authors: Venkatachalam R. , Sydulu M.
Published: February 2013

The phenomenon of self-locking is encountered in mechanical brakes. When a bake is self-locking, the friction torque tries to lock the brake drum completely; entirely on its own. In this paper, an attempt is made to investigate the phenomenon of self-locking, mathematically. An attempt is next made to verify the analytical development, through an experiment. Both the analytical and the experiment investigations agreed closely in the basic aspect that the braking torque grows very rapidly with time. The analytical development predicted that the braking torque grows as an exponential function of time. But the experimental investigation showed that the growth of braking torque is an exponential function of a power of time, indicating that the torque grows much faster.
A Summary of the Properties of Van Der Waals Fluids
Authors: Vent S. Le
Published: February 2013

The well-known van der Waals equation of state is described in standard textbooks and undergraduate courses in physical chemistry, and in chemical and mechanical engineering. Such descriptions generally outline the origin of terms extra to those found in the perfect gas equation and give typical values of the additional parameters involved. Generally, the various implications for fluids satisfying the equation are not covered to any extent, such coverage being scattered throughout more advanced chemical and engineering literature. The purpose of the present paper is to collect together some of the more important of these. Considered here are the various forms of the equation, vapour pressure implications, the compression factor, thermodynamic aspects, Joule and Joule—Kelvin coefficients and associated inversion phenomena.
Comparisons of Instructional and Complete Versions of Thermodynamic Engine Cycle Simulations for Spark-Ignition Engines
Authors: Caton Jerald A.
Published: February 2013

Instructional and complete versions of thermodynamics engine cycle simulations for spark-ignition engines were compared. The instructional version of the cycle simulation used constant specific heats as compared to using variable properties and composition for the complete simulation. For the proper selection of constant properties, the global engine performance parameters obtained from the instructional version of the cycle simulation were in close agreement to the values obtained from using the complete version of the simulation. The specific values of items such as maximum pressure and temperature, however, were not exactly duplicated. Examples are given based on a commercial, spark-ignition engine. For the cases studied here, the brake power and thermal efficiency as obtained from the constant property version of the simulation (for a ratio of specific heats of 1.30 and a gas constant of 0.287 kJ/kg K) were in excellent agreement with the same parameters from the complete simulation for a range of operating conditions.
Computer Models for Education on Performance Monitoring and Diagnostics of Gas Turbines
Authors: Mathioudakis K. , Stamatis A. , Tsalavoutas A. , Aretakis N.
Published: February 2013

The paper discusses how performance models can be incorporated in education on the subject of gas turbine performance monitoring and diagnostics. A particular performance model, built for educational purposes, is employed to demonstrate the different aspects of this process. The way of building a model is discussed, in order to ensure the connection between the physical principles used for diagnostics and the structure of the software. The first aspect discussed is model usage for understanding gas turbine behaviour under different operating conditions. Understanding this behaviour is essential, in order to have the possibility to distinguish between operation in ‘healthy’ and ‘faulty’ engine condition. A graphics interface is used to present information in different ways such as operating line, operating points on component maps, interrelation between performance variables and parameters. The way of studying faulty engine operation is then presented, featuring a novel comparison to existing simulation programs. Faults can be implanted into different engine components and their impact on engine performance studied. The notion of fault signatures on measured quantities is explained. The model has also a diagnostic capability, allowing the introduction of measurement data from faulty engines and providing a diagnosis, namely a picture of how the performance of engine components has deviated from a ‘healthy’ condition
Chemical Reactions and Gaseous Equilibrium
Authors: Lewins J. D.
Published: February 2013

The article gives a methodology for determining the direction of a reaction and the point where gaseous equilibrium exists, emphasising the minimum of the Gibbs function at chemical equilibrium. A new result is offered, Lewins' law on the effect of dilution and explicit formulae are given for some major reactions. The calculations involved can be readily performed with the aid of a computer programme. This approach is seen as particularly helpful for students of combustion processes who lack a chemistry background.
Thermal Engineering Design Project: A Calorimeter That Measures the Specific Heat of Aluminum
Authors: Mullisen R. S.
Published: February 2013

A thermal engineering design project requiring the design, construction, and operation of a calorimeter that measures the specific heat of aluminum was assigned to a class of third-year mechanical engineering students. Before making the assignment, the author developed his own design, which consisted of two individual calorimeters — each an assembly of 13 aluminum plates with electric resistance heater wires laced between the plates. The exterior surfaces of both calorimeters and the surrounding insulation were identical. However, the interior plates were different — one calorimeter had solid interior plates and the other had perforated interior plates. By initially adjusting the electrical power into each calorimeter the temperature versus time curves for each calorimeter were matched. This curve match allowed cancellation of the unknown heat loss from each calorimeter and cancellation of the unknown heater thermal capacity. The final result was a specific heat for the aluminum alloy that deviated by 4.4% from a published value. A class of third-year mechanical engineering students, working in teams, produced designs using the method of mixtures (aluminum and water) and electrically heated aluminum samples. The 17 student groups plus the author produced 129 data points with a mean specific heat value that deviated by 19.5% from a published value.
Optimising an Intercooled Compressor for an Ideal Gas Model
Authors: Lewins Jeffery D.
Published: February 2013

Many of the conventional results obtained when optimising the performance of an intercooler during compression using a perfect gas model can be obtained when the restrictions of the model are relaxed to an ideal gas. That is, we now have temperature-dependent specific heat capacities but retain the equation of state pV = RT. This note illustrates the theme.
A Novel Approach to the Teaching of Planar Mechanism Dynamics – A Case Study
Authors: Sinatra Rosario , Angeles Jorge
Published: February 2013

We propose a novel approach to the teaching of undergraduate planar mechanism dynamics. To illustrate the approach, we use a case study, the dynamics of the planar slider-crank mechanism. In this case study, we make extensive use of an operator representing in two-dimensional form the cross-product of two vectors. Furthermore, by using the natural orthogonal complement, introduced elsewhere, we produce a systematic procedure to derive a dynamic model of the same class of mechanism. Subsequently, we illustrate how, with the use of the aforementioned operator, the dynamic balancing of this mechanism, as first proposed by Berkof and Lowen for RRRR planar linkages, and extended by Bagci to the slider-crank mechanism, simplifies tremendously.
Integration of Boiling Experiments in the Undergraduate Heat Transfer Laboratory
Authors: Abu-Mulaweh Hosni I. , Libii Josué Njock
Published: February 2013

This paper presents two boiling experiments that can be integrated in the undergraduate heat transfer laboratory. The objective of these experiments is to enhance the understanding of the boiling process by undergraduate mechanical engineering students. These experiments expose students to several important concepts in boiling, such as subcooled boiling, modes of pool boiling, and the Leidenfrost phenomenon. The experimental set-up required to carry out these experiments is simple. It includes metallic plates such as brass, stainless steel or aluminium, a heating source such as a heating pad, thermocouples, a stopwatch, a liquid dropper, and a camera. The equipment is inexpensive and available in almost all undergraduate heat transfer laboratories.
Three-Directional Grating and Application in Measuring Residual Stresses
Authors: Chen JuBing
Published: February 2013

The performance of mechanical parts is influenced by residual stresses on grinding surfaces. Because of the randomness of residual stresses, they are very difficult to determine by theory. A three-directional grating is presented by the author, and by means of the moiré interference technique and hole-drilling, a new method of residual stress measurement is developed. Further, the residual stresses on grinding surfaces are given.
A Slider-Crank Experiment to Determine the Action of Static Forces
Authors: Ng T. W.
Published: February 2013

A simple experiment to demonstrate the action of static forces in a slider-crank mechanism is described. Despite the apparent simplicity of the set-ups used, the experiment was able to produce measurements that were close to those predicted by kinetics analysis theory. More importantly, it was highly successful in helping students grasp the fundamental concepts of static forces operating in slider-crank mechanisms in an experiential manner.
A Graphic Representation of Traction for a 3D Elastic/Plastic Stress State
Authors: He Zhubin , Wang Z. R. , Teng Bugang
Published: February 2013

The stress ellipsoid is often used to describe the variation scope of total stress of one stress state. But the direction of one vector from the original point to the ellipsoid surface is not always the one of the corresponding acting plane. A 3D graphic representation of total stress for an elastic/plastic stress state is given in this paper for the first time. The magnitude of the total stress on one plane can be described by the projection along the corresponding normal direction. The real direction of the total stress can be given directly. In a principal axes system, the figure is symmetric about the three principal axes. As for a plastic stress state, the stereograph of total stress has its own characters because the yield criterion must be obeyed. From the total stress figure, it is easy to get the magnitude of total stress acting on a certain plane. It is very helpful in understanding the concept of the stress ellipsoid and the variation of total stress across different acting planes.
Engineering Visualization and Modeling: Teaching and Management Using the IT Approach
Authors: Lee K. S. , Low Maria L. H.
Published: February 2013

A web-based E-learning courseware for the module ME1101, Engineering Visualization and Modeling, has been developed to complement the normal lectures, practical work and tutorials at the National University of Singapore (NUS). This courseware includes the lecture notes, the solutions and worked examples in animated format, related videos to emphasize the finer details of manual drawing concepts and online quizzes to enable students to learn better. A number of information technology (IT) tools are being used in the courseware development. The Integrated Virtual Learning Environment (IVLE), developed in-house by the Centre for Instructional Technology (CIT) at NUS, has also played a large role in assisting the instructor and tutors for the module to better manage the course. The courseware developed is especially useful to students from other faculties who do not have any technical knowledge.
Vibration and Stability of Uniform Euler–Bernoulli Beams with Step Change in Axial Force
Authors: Naguleswaran S.
Published: February 2013

Beams which carry a constant axial force in one portion of the beam and a different axial force in the rest of the beam occur in engineering applications. The system parameters are the position where the axial force change occurs and the two axial force parameters. Transverse vibration of such systems (based on the Euler—Bernoulli theory of bending) is considered in this paper. Tables of the first three frequency parameters are given for various combinations of classical boundary conditions and system parameters. High-precision computing is necessary to handle large axial forces. It is possible for a natural frequency to be zero for certain combinations of the system parameters. This is Euler buckling and a table of combinations of critical system parameters is given. Transverse vibration of tie-bars (a special case of the title problem) is covered in textbooks but benchmark frequencies are not documented. In the paper, a table of frequency parameters of beams carrying tensile or compressive axial forces is given for all the combinations of classical boundary conditions.
On Various Eigenvalue Problem Formulations for Viscously Damped Linear Mechanical Systems
Authors: Gürgöze M.
Published: February 2013

The state-space method is frequently used to obtain the eigenvalues of a viscously damped linear mechanical system. Differences in the definition of the state vector and auxiliary matrices found in the literature lead to differences in the formulation of the eigenvalue problems and this in turn can cause difficulties for students on mechanical vibration courses. In this study, various eigenvalue problem formulations in different textbooks have been examined, relationships between them have been established and results have been applied to a numerical example of a system with two degrees of freedom.
Instantaneous Center of Rotation and Singularities of Planar Parallel Manipulators
Authors: Daniali H. R. Mohammadi
Published: February 2013

With regard to planar parallel manipulators, a general classification of singularities into three groups is given. The classification scheme relies on the properties of instantaneous centers of rotation. This method is very fast and can easily be applied to the manipulators under study. The method is applied to a planar three-degrees-of-freedom parallel manipulator and all its singular configurations are found.
Reproduction of the Fin Efficiency Diagram for Annular Fins of Uniform Thickness by Solving Systems of up to Four Algebraic Equations
Authors: Campo Antonio , Chikh Salah
Published: February 2013

This paper addresses a simple finite-difference procedure for solving the modified Bessel equation that governs the temperature variation along annular fins of uniform thickness with constant thermal conductivity and a uniform convection coefficient. After performing several numerical experiments for critical cases related to large radii ratios, c, and reasonable values of the enlarged Biot numbers, γ2, it was found that heat transfer rates of good quality can be obtained by solving systems of up to four algebraic equations with the spreadsheet software Excel. Later, with the numerical fin efficiencies, η, gathered for all practical combinations of c and γ2, the entire fin efficiency diagram can be easily reproduced.
The Conjugate Method for Solving Mono-Axial Frames
Authors: Falsone G.
Published: February 2013

This paper discusses materials for a course on ‘Strength of materials and mechanics of solids’, addressed to students of second-year mechanical engineering, ocean engineering, civil engineering and aerospace engineering. In particular, the problem of the evaluation of the deflection and of the axial displacement of elastic mono-axial frames is considered. This problem is solved by the use of a generalization of the classical conjugate beam method, that here is defined conjugate mono-axial frame method. It lies on the similarity between all three kinematic differential equations governing the elastic deflection and axial displacement of the mono-axial frame and all three static differential equations governing its equilibrium. This implies some comparisons and theorems that are reported in the present paper. The mode of presentation of this material is by lecture, within a regular course, of 3–4 hours, with 2–3 revision hours. The material must be presented after the classical elastic beam and frame problem has been treated. The material helps students to analyse the important relationships between the kinematics and the statics of any elastic structure.
Apparatus for Demonstrating Self-Excited Vibrations in Fluid Flow
Authors: Pejack E. R.
Published: February 2013

This paper describes an experimental apparatus that demonstrates some examples of self-excited vibrations in fluid mechanics. Such vibrations become unstable without an external perturbation but are characterized by an initially stable system with steady flow. The system extracts from the flow and exhibits increasing amplitude of vibration. Two experiments are described, one dependent on area change in ducted flow and the other dependent on the change in flow direction in a double pendulum. Mathematical analyses are developed which establish the stability criteria for the self-excitation observed.
Study of Dynamic Thermal Response and Implementation of Proportional Integral Derivative (PID) Controllers in Buildings Using Spreadsheet Models
Authors: Lowry Gordon
Published: February 2013

Difficulties arise in the teaching of control concepts applicable to thermal systems in buildings because these systems are large and respond slowly. Also, traditional control system analysis does not easily accommodate the examination of real scenarios. In this paper, spreadsheet-based techniques are described that allow students to simulate thermal responses using real and hypothetical data. Controller tuning can be simulated and alternative designs can be simultaneously examined and compared. The spreadsheet models are routinely used by distance-learning students, but have proved useful also in teaching full-time students on campus.