bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Second Regions of Dynamic Instability of a Uniform Beam
Authors: Ganguly Snehasis , Datta P. K.
Published: February 2013

Dynamic instability of a beam is solved for second regions of instability. The governing equations are of the Mathieu—Hill type, where the parametric regions are sought. While the solution to the first region of a beam has been widely reported, there is none available in the literature for the second region. In this work, the regions are determined by the finite element method. Bolotin determined the solution analytically, but it is more of a qualitative solution of the problem. In this work, a quantitative solution is sought from the finite element method. The width of the regions are significant. The effects of the static load factor and the dynamic load factor are obtained.
CAL-based CADCAM Training for Manufacturing and Mechanical Engineers
Authors: Cripps R. J. , Spencer R. R.
Published: February 2013

We describe the CAL-based training for CADCAM designed specifically to teach level-2 undergraduate mechanical and manufacturing engineers the fundamentals of computer-based design and manufacture of three-dimensional components. The work has been ongoing over the last decade and we describe the development of the material from its paper-based beginnings to the current webenabled, CD-ROM-based environment. In particular, we review the lessons learnt from continuous feedback and improvement, marking the CAL approach as a success. This has to be taken in the context of the large initial investment required to produce the material. The software products PowerShape and PowerMill developed by Delcam plc, were used for surface modelling and manufacture, respectively.
Control Theory, Delays and Driving an Automobile
Authors: Engelberg Shlomo
Published: February 2013

A simple model of the driver—automobile system is developed and several reasonable candidates for the transfer function of the human ‘controller’ are studied. The model is used to examine the controller candidates. The complete system is analysed both analytically and through simulations. It is found that a delay followed by a phase-lead controller is a reasonable choice for the transfer function that the human ‘controller’ implements. The model developed is compared with a more realistic model and is seen to be a reasonable approximation of the realistic model at low frequencies. Reaction time is shown to be a critical parameter in understanding the dynamics of the driver—automobile system.
Limit Moments for Pipes with Circumferential Through-Wall Cracks: Experimental Verification
Authors: Castiaux S. , Moffat D. G. , Mistry J.
Published: February 2013

Experiments on copper tubes with simulated cracks and slots in them are used to provide justification of the classical approach to assessing the limit moment carrying capacity of cracked tubular components.
An Introduction to the Finite Element Method Using MATLAB
Authors: Mueller Donald W.
Published: February 2013

This paper outlines an efficient approach to introducing the finite element method to undergraduate mechanical engineering students. This approach requires that the students have prior experience with MATLAB and a fundamental understanding of solid mechanics. Only two-dimensional beam element problems are considered, to simplify the development. The approach emphasizes an orderly solution procedure and involves important finite element concepts, such as the stiffness matrix, element and global coordinates, force equilibrium, and constraints. Two important and challenging engineering problems — a statically indeterminate beam structure and a stepped shaft — are analyzed with the systematic solution procedure and a MATLAB program. The ability of MATLAB to manipulate matrices and solve matrix equations makes the computer solution concise and easy to follow. The flexibility associated with the computer implementation allows example problems to be easily modified into design projects.
A Simple Tool for Engineers for Generating Formulae for the Sum of Powers of Natural Numbers
Authors: Venkatachalam R. , Sharma Umesh Chandra
Published: February 2013

The formulae for the sum of powers of natural numbers are in the form of polynomials. These formulae are derived using an algorithm which was developed from a simple geometric interpretation. It has been found that these polynomials are interdependent. In this paper, a close study is made and many interesting features are brought out. A method is proposed to generate a new polynomial based on the features of these polynomials. Another simplified algorithm is also presented which is found to be more suitable for the automatic generation of the polynomials. The latter may be realized as a convenient and handy tool for generating the formulae, especially for engineers.
A Basis for Teaching Centrifugal Pump Characteristics in an Undergraduate Course in Turbomachinery
Authors: Ntoko Nzumbe-Mesape , Djidjou Kamdem , Harrison Ndetan
Published: February 2013

The paper presents a basis for teaching centrifugal pump characteristics in an undergraduate course in turbomachinery. It is shown how the shock and frictional loss coefficients, key factors in the determination of pump characteristics, can be appropriately obtained. The first coefficient is obtained from the difference between the drag at a reference incidence and that at zero incidence, while the second is obtained from correlations for frictional loss in a spiral. The coefficients so obtained were used to obtain the real characteristics of a centrifugal pump impeller.
On the Use of Audio-Tapes for Teaching Vector Analysis to Engineering Undergraduates
Authors: Rees J. M. , Atkin R. J. , Zimmerman W. B.
Published: February 2013

An audio-tape with an accompanying booklet of notes has been prepared specifically for teaching the topic of vector analysis to engineering undergraduates in their second year of study at Sheffield University. The audio-tape package was designed to replace four conventional lectures. The implications of introducing an innovative teaching practice into a mathematically based discipline are discussed. The reactions of two cohorts of students on whom this teaching innovation was trialled are described. It was deduced that students are likely to be more receptive to an alternative teaching practice if they are encouraged to participate in the decision-making processes concerning the details of its implementation. Such activities generate the concept of ‘shared ownership’, which tends to promote more positive student feedback.
Design and Fabrication of a Cartesian Painter Robot for the Construction Industry
Authors: Aris Ishak Bin , Iqbal A. K. M. Parvez
Published: February 2013

Nowadays robots are used in many applications (in factories, mining industries, automobile industry, etc.). Currently, robots have still not been widely implemented within the construction industry, however, although robots have been designed to increase the speed and improve the accuracy of construction field operations. They can also be used to do hazardous and dangerous jobs in construction. For example, house painting is usually done manually, but could be simplified using a dedicated robot. In particular, it is difficult for a human being to work overhead, for example painting a ceiling. It can also present a danger to the eyes. To overcome these difficulties, a robotic system which is capable of painting houses and buildings is proposed and developed. This paper describes all the processes involved in developing the proposed painter robot. The project is divided into two main parts, namely hardware and software. In the hardware part the mechanical design, fabrication, electrical and electronics system are described, and in software part the control algorithm is described.
On the Nonlinear Response of Zero-Force Members
Authors: Tóth Krisztina , Domokos Gábor
Published: February 2013

In this paper the nonlinear response of zero-force members is investigated in linear elastic pin-jointed trusses and it is shown that in such members the normal force is typically a quadratic function of the load parameter, and so the sign of the normal force does not depend on the sign of the load. A simple, intuitive method is provided to determine the sign of the normal force. A ‘degenerate’ example is also demonstrated, containing zero-force members in which the dependence of the internal force on the load parameter is of arbitrary order.
Vibration of a Euler–Bernoulli Uniform Beam Carrying a Rigid Body at Each End
Authors: Naguleswaran S.
Published: February 2013

Publications on the vibration of a Euler—Bernoulli beam carrying thin discs at the ends are available. In this paper the thin discs are replaced with rigid bodies, whose axial width is included in the analysis. The centre of mass of the bodies is assumed to be on the beam axis but away from the beam end. Among the boundary conditions considered are: the classical clamped, pinned, sliding of free; the lateral translation and rotation of an unrestrained rigid body; the translation and/or rotation of a restrained rigid body, and other special cases. The frequency equations and the first three frequency parameters are tabulated for several sets of the system parameters and selected combinations of 10 boundary conditions.
Correlation Equation for Heat Transfer Coefficients for Circular Pin Fins
Authors: Abu-Mulaweh H. I. , Mueller D. W.
Published: February 2013

The objective of this study was to develop and present a correlation equation for the representative or ‘average’ heat transfer coefficient associated with horizontally oriented circular pin fins that accounts for the effect of both modes of heat transfer, convection and radiation. Four aluminum test pins of circular cross-section with diameters of 3.18, 6.35, 9.53, and 12.7 mm were used to develop the correlation equation. This correlation is supplied to students in the undergraduate heat transfer laboratory for use in the design of a fin attachment using the design—build—test approach. In the experiment, student teams design, build, and test a fin attachment to increase the heat loss from a surface.
Gibbs' Thermodynamics of Wetting
Authors: Toshev B. V.
Published: February 2013

According to Gibbs, the interface between a solid and a fluid phase can be split into two parts, one belonging to the solid and the other to the fluid. Correspondingly, the work (ω) of forming the interface can be represented as the sum of the work (ωs) of forming the solid surface in a vacuum and the work (ρ) of forming the fluid part of the interface. The quantity ρ, called by Gibbs the ‘superficial tension of the fluid in the contact with the solid’, can be treated either as energy or as a force, like the surface tension of a liquid. The implications of introducting ρ quantities to the thermodynamics of wetting are considered and the advantage of constructing the theory in this way is demonstrated.
On the Formulation of Lagrange's Equations with Respect to Moving Coordinate Systems: Application to a Point Mass Vibrating on a Rotating Base
Authors: Gürgöze M.
Published: February 2013

Lagrange's equations are a well known tool for establishing equations of motion of discrete systems. Kinetic energy, which plays a central role in their use, has to be formulated with respect to an inertial system. Lagrange's equations can be formulated favorably with respect to a moving coordinate system as well (e.g. for mechanical systems which themselves are on a moving base), in that the relative kinetic energy is employed. This enables one to get better insight into various inertia forces. The theory revisited is applied to a point mass vibrating on a rotating base.
Incorporating the Development of a Graphical User Interface in Courses Teaching Numerical Methods for Engineers
Authors: Kosasih P. B. , Tieu A. K.
Published: February 2013

This paper describes how students' learning interests can be stimulated and their understanding of topics in numerical methods can be improved by incorporating the development of graphical user interface (GUI) in a numerical methods course or related courses. The students' interest and understanding are raised because they are able to implement the theory to solve practical problems and see how the methods can be used in practical situations with the help of the GUI that they design and create. To illustrate how development of GUI can be incorporated into numerical methods courses, two illustrative examples are given: solution of systems of ordinary differential equations related to vibratory motion of masses, springs and dampers system; and solution of an elliptic partial differential equation (i.e. Poisson equation). The tool of choice in the authors' class was MATLAB. The two examples have been tested on final-year undergraduate and postgraduate engineering courses. The authors also discuss delivery strategy of GUI-related materials in their numerical course.
Technical Drawings and Virtual Prototypes
Authors: Romero G. , Maroto J. , Martínez M. L. , Félez J.
Published: February 2013

This article describes a program that uses virtual reality techniques to allow mechanisms to be viewed, moved and manipulated. These mechanisms can be assembled/unassembled and checked to see if they work properly. A virtual environment is used and the mechanism can be seen by different ways using a head-mounted display or stereoscopic glasses. This program is an example of how it is possible to adapt traditional subjects, like engineering drawing, to the new technologies of visualization and simulation. In order for the program to be used via the Internet, it supports a VRML file that can be view with Internet Explorer software.
On the Circulation and the Position of the Forward Stagnation Point on Airfoils
Authors: Meseguer J. , Alonso G. , Sanz-Andrés A. , Pérez-Grande I.
Published: February 2013

Lift and velocity circulation around airfoils are two aspects of the same phenomenon when airfoils are not stalled and the Kutta—Joukowski theorem applies. This theorem establishes a linear dependence between lift and circulation, which breaks when stalling occurs. As the angle of attack increases beyond this point, the circulation vanishes. Since the circulation determines to a great extent the position of the forward stagnation point on an airfoil, the measurement of this position is an easy and simple way to determine the circulation, which is of help in understanding the role of the latter in the generation of aerodynamic forces on airfoils.
Instantaneous Center of Rotation and Centrodes: Background and New Examples
Authors: Zypman Fredy R.
Published: February 2013

We review the concept of instantaneous center of rotation and its loci, the moving centrode and the fixed centrode, for the plane motion of an arbitrarily shaped rigid body. Then we recall a simple example from the literature. Finally, we present two new solutions pertaining to the motion of an elliptical lamina on a fixed plane, and of a stick moving on an oblique corner.
Reciprocal Theorems: An Old Subject Revisited
Authors: Tarnai T. , Lengyel A.
Published: February 2013

While discussing reciprocal theorems most textbooks mention only Maxwell's reciprocal theorem as a consequence of Betti's theorem. Textbooks investigating this topic in detail mention three reciprocal theorems. In this paper we show that there exist exactly 10 reciprocal theorems and we illustrate each with an example.
Software Demonstration of Disc Cam Mechanisms for Mechanical Engineering Education
Authors: Hoorfar M. , Najjaran H. , Cleghorn W. L.
Published: February 2013

This paper describes a software program for the kinematic analysis and design of disc cam mechanisms. It was mainly developed to enhance student learning in an undergraduate mechanisms course within a mechanical engineering curriculum. The software includes numerous combinations of follower types and motions, and provides graphical representations of the kinematics of the follower. The cam profile may be shown with or without the follower in a single position or animated. The software provides design tips in the form of error and warning messages when the user attempts to enter invalid values of input parameters. The software tool can also be used to design and test complicated cam mechanisms for industrial applications. Two examples are presented that demonstrate some important problems involved in the design of cam mechanisms.
Simulation of a Direct Evaporative Cooler and a Cooling Tower by the Effectiveness—NTU Method
Authors: Bougleux P. A. F. , Saboya F. E. M. , Marques R. Pitanga , Parise J. A. R.
Published: February 2013

A direct evaporative cooler and a counter-flow cooling tower were simulated by the effectiveness–NTU method. One-dimensional energy and mass balance as well as heat and mass transfer equations were applied. The resulting algebraic equations were solved numerically. To validate the simulation model, numerical results of the evaporative cooler and cooling tower were compared with available experimental data. This simple application of the effectiveness–NTU method to such important heat transfer devices may prove pedagogically useful to undergraduate mechanical engineering students attending heat transfer courses.
On the ‘Proof’ of Assumptions in the Basic Theories of Bending and Torsion
Authors: Ilanko Sinniah
Published: February 2013

In the theory of beam bending, transverse sections of a beam are assumed to remain plane during bending. In torsion analysis, the radii of shafts of circular cross-sections are assumed to remain straight during twisting. Some popular textbooks present mathematical proofs for these statements. This article shows that these proofs are incorrect and that these statements should be treated as assumptions.
The Integrated Application of Microcontrollers in the Team-Based ‘Design and Make’ Project
Authors: Alemzadeh Kazem , Wishart Clive L. , Booker Julian D.
Published: February 2013

This paper describes a mechatronics-based project which is part of the first-year Design and Manufacture course in the Department of Mechanical Engineering at the University of Bristol. The project introduces students to the use of novel and integrated microcontrollers as part of a complete product development cycle. The project involves the design and manufacture of a microcontroller-based vending machine in an active learning environment. This is a team-based project carried out over two terms; it lasts 60 hours, spread over seven weeks in the spring term and a one-week ***post-examination build phase in the summer term. Many of the engineering principles learned are applied in order to conceive, detail, cost, plan and build a vending machine to a product design specification, mirroring industrial product development. The nature of the project allows students to learn about the interface of sensors and actuators through the use of a recently adopted microcontroller package.
Delivery and Assessment Strategies to Improve on- and off-Campus Student Performance in Structural Mechanics
Authors: Hall Wayne , Palmer Stuart , Ferguson Clive , Jones J. Trevor
Published: February 2013

This paper considers the delivery and assessment strategies used in two structural mechanics units at Deakin University, a leader in distance education in Australia. The two units have had unacceptably high rates of student failure. Student perceptions of the delivery method were analysed and an investigation was carried out of the performance of 329 (173 on- and 156 off-campus) students enrolled in the two units. An analysis of the assignment, laboratory and examination marks is presented. Consideration is also given to the total marks. The results show that on-campus students performed better in structural mechanics than their off-campus counterparts. Plots of the distributions of student performance for the three assessment methods are provided (for each unit) and high failure rates are linked to low examination marks. Students tended to perform best in assignments and worst in examinations. Parametric statistical tests show a correlation between the marks obtained in continuous assessment and in examinations, and it is therefore proposed that, in order to improve performance, the students must be encouraged to participate fully in all aspects of the course. Many students were unenthusiastic about laboratory practical sessions and did not think they aided their understanding of the theoretical material. Motivation to participate is often dependent on the perceived relevance of a given task and its contribution to the total mark and, thus, to help motivate students to participate fully in the continuous assessment tasks, the authors propose several changes to the delivery methods, as well as to assessment criteria and marking schemes.
Development of a Lightweight Box Structure for Static Structural Experiments
Authors: Kuntjoro Wahyu
Published: February 2013

It is important to expose university students to practical experiments. In this way, they will appreciate more the subjects which they learn. This paper reports on the development of a lightweight box structure with which students can perform static structural experiments. The box simulates the wing box of a two-spar wing structure, and is intended for aeronautics engineering undergraduate students in a practical laboratory. All materials were purchased from high-street shops. To determine the characteristics of the sheet metal aluminum alloy that was purchased, tensile tests were performed. A preliminary analysis was performed to obtain the stress of the box for a certain loading. Further analysis was conducted using the finite element method. Manufacturing of the box consisted of conventional sheet metal cutting, metal forming, and sheet metal assembly. The box was then tested to obtain the stress due to static tip loading. The stresses were obtained through strain gauge readings. The readings were then compared with the theoretical and finite element analysis. The data from these analyses were then used as part of the practical laboratory.
The Design of Planetary Gear Trains: Application of Optical Fiber Polishers
Authors: Hsieh Long-Chang , Lee Hsin-Sheng , Wang Zhi-Yi
Published: February 2013

This paper mainly discusses the planetary gear trains design, and uses the optical fiber polishers as an example of application. Firstly, displacement, velocity, and acceleration equitations for the grinding track are derived in order to find out how design parameters affect grinding characteristics. Then, based on the grinding velocity, the velocity deviation percentage ( Vdp) is calculated, which is an important design parameter. Another important design parameter is the polishing area percentage ( App). In the paper, we select two planetary gear trains: the first produces epicycloidal tracks on the planetary gear surface; the second produces hypocycloidal tracks on the planetary gear surface. The paper analyzes these two planetary gear trains in order to find their optimized designs as fiber polishers. The project provides application experience in the design of transmission systems.
An Undergraduate Design Exercise at Rolls-Royce Plc
Authors: Lock G. D. , Wright C.
Published: February 2013

The Department of Mechanical Engineering at the University of Bath has been conducting an undergraduate engine-related design exercise at Rolls-Royce, Bristol, since 2000. Each year, between February and September, a team of six undergraduates completes an engine-related design project under supervision from the company. This work is co-ordinated and assessed at both the company and university, and counts overall as 20% of the student's four-year degree. In addition to working at Rolls-Royce, the students submit reports and give seminars at the university. The design exercise is predominantly technical in nature but must include a significant business element. The students are paid as company employees, typically £7200 for the six months. This paper describes the design exercise and how it is accommodated within the undergraduate programme of study at the university. The benefits to the university, the students and the company are discussed. In addition, the six students undertaking the 2005 exercise describe their projects. In 2005 there were three projects: an experimental and computation study of engine vibration using a rotor-dynamics rig, simulating the engine; a study to create a tool to enable the designer to evaluate the environmental aspects of the life cycle of an engine component; and various design aspects of aero-engines, both computational and business.
An Experimental Study of a Collector and Diffuser System on a Small Demonstration Wind Turbine
Authors: Ghajar R. F. , Badr E. A.
Published: February 2013

A diffuser-augmented wind turbine (DAWT) has been an attractive concept of wind energy extraction since the early 1970s, due to the system's ability to increase the power generated by a regular bare turbine of the same size. However, the DAWT needs to reach a minimum augmentation ratio of 4 in order to become economically feasible. This paper investigates the possible improvement of a DAWT system by adding a collector fuselage to increase its augmentation ratio. Testing using a small experimental unit shows that adding a collector increases the power augmentation of the DAWT by more than 50%, and increases the mass flow rate through the turbine by increasing the effective upstream area of the wind that enters it. Changing the angle of the incident wind on a collector- and diffuser-augmented wind turbine (CDAWT) shows that it is possible to capture the energy in the wind up to an angle of 71°. Moreover, the CDAWT can keep extracting wind energy, without any diminution of the augmentation ratio, as wind direction varies ±45° from the turbine axes, thus eliminating the requirement for a yaw mechanism. Hence, the variant wind direction has a positive effect on the augmentation ratio.
Finite Volume Computational Fluid Dynamics Package for Solving Convective Heat Transfer Cases
Authors: Junaidi H. , Henderson D. , Grassie T. , Currie J. , Muneer T.
Published: February 2013

Computational fluid dynamics (CFD) has brought a step change in the field of flow analysis, particularly in the areas of fluid dynamics and heat transfer, which are intertwined. It has carved a niche in applications where, a decade back, experimentation was the only way forward. This article covers the benchmarking of convective heat transfer cases through the use of CFD software. The cases investigated are common cases of heat transfer involving free convection and one case involving forced convection. The results from CFD analysis are compared with the regressions available for each test case. The two sets of data coincide well, with a percentage difference as low as 0.4%. Information on setting up CFD analysis accurately, particularly for solving problems of natural convection, is also included.
Application of Finite Elements for Determination of the Damping Coefficient of an Eddy Current Damper Using Matlab
Authors: Das A. S. , Nandi A. , Neogy S.
Published: February 2013

A vibration damper based on an eddy current is a frequently used electro-mechanical system. This paper deals with determination of the damping coefficient of such an eddy current damper. For this purpose, Maxwell's relations are simplified to a single quasi-harmonic equation and solved using finite elements. The finite element analysis is done using ‘PDEtool’ in Matlab. The graphical post-processing is performed partly using PDEtool and partly using a short Matlab code.
Calculations and Hypotheses concerning the Energy Return on Energy Invested, with Reference to Hydrocarbon Fuels
Authors: Jones J. C. , Cardno S. , Service J. , Udensi I.
Published: February 2013

Honours project work by the second, third and fourth of the above-named authors under the supervision of the first is described. It relates to the energy return on energy invested for two hydrocarbon resources: crude oil and natural gas hydrates. Information obtained from the web has been evaluated and organised into a synthesis which, it is believed, will be of interest both to a specialist in such matters and to a reader seeking an introductory coverage.
Creative Design of an Elliptical Trainer with Two Degrees of Freedom
Authors: Lee Hsin-Sheng
Published: February 2013

The elliptical trainer is a widely used piece of equipment for fitness and rehabilitation. An elliptical trainer with seven links and eight joints, and two degrees of freedom, can have its range of motion adjusted to match the user's stature, and the user can obtain different athletic effects. It allows for more adjustment than an elliptical trainer with one degree of freedom. In this paper, we refer to the present patents that specify the design requirements and constraints for an elliptical trainer. We then use Yan's creative mechanism design methods, which include generalized principles, number synthesis, specialization, and particularization, to obtain a practicable structure for an elliptical trainer with two degrees of freedom. We obtained five alternative kinds of mechanism. We chose one of them for a simulated kinematic analysis, and manufactured the prototype. This paper can serve not only as a reference for the development of fitness equipment but also as a teaching tool for creative mechanism design courses.
Re-Engineering of a Shifter Kart for Improved Performance
Authors: Freeman David , Bennett Christopher , Bajon R. , Guo S. M.
Published: February 2013

This paper describes a new senior design project offered at Louisiana State University's Mechanical Engineering Department. The project was aimed at improving the performance of a 125 cc racing shifter kart in order to give the kart a competitive edge at three different types of racing events (autocross, sprint races, and road races) and good reliability during pre-race testing. Although similar design projects exist in the Mechanical Engineering Department, most racing-related projects primarily use off-the-shelf components. While these are worthwhile, they do not give students the satisfaction of being involved with the end-to-end life cycle of a complex engineering project, from conceptual design, fabrication, integration and testing to actual operation of the system. This project fulfills that need. Two approaches were taken in this project to accomplish a better performance for the racing shifter kart: one was to create a new exhaust for more power at low and medium engine speeds, while the other was to create a new front fairing to reduce the kart's coefficient of drag. This paper describes the design strategies, the fabrication processes, the final test results, and lessons learned from this project.
Salient Features of a Lecture Course on Reliability Theory
Authors: Csenki Attila
Published: February 2013

The module ‘oReliability Modelling and Analysis’ has been taught by the author at the University of Bradford in the School of Informatics over several years. In this paper, four aspects of the lecture course are described. After reviewing the general course structure, we examine within the field of maintenance modelling the method of marginal cost analysis. The application of this technique is deemed to be novel in the present (teaching) context and it is intended to make a basically mathematical subject amenable also to engineers and economists. Next, we outline the use of the computer algebra package Maxima in teaching ‘reliability’. This is exemplified with a classroom example, an exercise and a coursework assignment. Experience shows that the use of Maxima enriches the teaching of reliability to aspiring practitioners. Finally, some general principles are reviewed which help the learner to keep an eye on the reasonableness of purported results, using properties such as model structure, model symmetry, dimensional correctness, boundary conditions, specialization and generalization.
Adding a Continuous Improvement Design Element to a Sophomore-Level Thermodynamics Course: Using the Drinking Bird as a Heat Engine
Authors: Lang Amy Warncke , Puzinauskas Paulius V.
Published: February 2013

To increase the design experience gained by undergraduate engineering students and to enhance their iterative thinking skills needed in the engineering profession, a new project was developed and assigned in the sophomore-level thermodynamics class taught at the University of Alabama. Students designed a mechanism using a toy drinking bird as a heat engine with the goal of minimizing the time required to raise a small weight a given distance. Besides building teamwork and design skills, several key thermodynamic concepts were also visualized for the students, thus increasing their overall comprehension of the course material.
A Wind Tunnel for an Undergraduate Laboratory
Authors: Kubesh Rodney J. , Allie Bret W.
Published: February 2013

The design and construction of a wind tunnel suitable for use in an undergraduate laboratory are described. The wind tunnel has proved to be an economical addition to a course on meteorological instrumentation, and a similar design would be useful in instruction in many fields of engineering and science, as it provides valuable ‘hands on’ experience to complement theoretical coursework. In our experience at Saint Cloud State University, student attitudes to use of the wind tunnel facility have been very positive.
Service Learning as Pedagogy for Promoting Social Awareness of Mechanical Engineering Students
Authors: Dukhan N. , Schumack M. R. , Daniels J. J.
Published: February 2013

Engineering education agencies worldwide echo the need of graduating engineers to be aware of the societal context of engineering. Service learning is a viable pedagogy that can bring students to understand this dimension in a rather direct way. Undergraduate engineering students visited low-income households in their community and installed insulation materials on doors and windows, thereby reducing heating costs. The students calculated the resulting dollar amount of energy savings using heat transfer principles. A quantitative analyses of the reflections of the students clearly showed that they became more aware and sensitive to their roles as engineers in a societal context.
Two Case Studies for the Effect of Beam Offset in Finite Element Calculations
Authors: Zamani Nader G. , Gharib Nima , Kaloni P. N.
Published: February 2013

This paper describes the effect of beam offsetting in finite element calculations. The effect is evaluated by considering two case studies involving beams, in which finite element analysis is performed with solid elements and with shell elements. It is seen that, under certain conditions, ignoring the beam offset can lead to erroneous results. Although the beam offsetting feature is available in most commercial codes, it is not always well documented.
Mechanism Analysis with Mathematica
Authors: Marghitu Dan B. , Raju P. K.
Published: February 2013

In this paper, planar mechanisms with dyads are analyzed using Mathematica. First, a classification of dyads is introduced and then Mathematica packages for the analysis of the driver link and dyads are explained. The analysis provides a consistent coding scheme for planar mechanisms. The advantage of the group classification of a system lies in its simplicity. The solution of the whole system can then be obtained by composing partial solutions. This approach will eliminate the need to store complete mechanism information in a large database.
Development and Performance Validation of Portable Air-Conditioning Experimental Apparatus
Authors: Abu-Mulaweh Hosni I.
Published: February 2013

A bench-top air-conditioning experimental apparatus was designed, developed, and constructed for instruction and demonstration purposes. This air-conditioning experimental set-up was designed around the vapor compression refrigeration cycle. It is reliable, safe for student use, and portable. The apparatus has an intuitive user interface that supports data acquisition by a computer. The unit is capable of demonstrating air-conditioning processes such as cooling, heating, and humidification. The level of cooling, heating, and humidification is monitored and controlled using a PC-based control system which consists of LabVIEW and a data acquisition unit. The system can also be used to demonstrate the fundamentals of the refrigeration cycle and the psychrometric properties of air, as well as some fundamental concepts and principles in heat transfer, heat exchangers, and thermodynamics. This paper provides details about the development of this unit and the integration of the electrical/electronic components and the control system.
A Perpetual-Motion Machine Problem for Teaching Fluid Mechanics and Thermodynamics
Authors: Naylor David
Published: February 2013

A perpetual-motion machine (PMM) problem is described which the author has used for more than a decade to augment a traditional textbook-centred course. Two proofs for debunking a ‘buoyancy engine’ PMM are given. One solution is based on the principles of fluid statics, requiring the calculation of hydrostatic and buoyancy forces on submerged surfaces. An alternative solution is based on an energy method, requiring the calculation of the work done by a moving boundary. These analyses are well suited for instructional purposes on a first course in fluid mechanics or thermodynamics. The author has found that this type of puzzle can be used to generate a high level of student interest and classroom participation, with only a minor commitment of lecture time.
The Experience of the Faculty of Mechanical Engineering, Universiti Teknologi MARA, Malaysia, with Accreditation by the UK Institution of Mechanical Engineers
Authors: Jaffar Ahmed , Omar Abdul Rahman , Jaafar Roseleena
Published: February 2013

The Faculty of Mechanical Engineering Universiti Teknologi MARA, Malaysia, has sought accreditation from the UK Institution of Mechanical Engineers (IMechE) for its Bachelor of Engineering (Honours) Mechanical programme. To be accredited, the programme must satisfactorily incorporate the UK-SPEC general learning outcomes, which have to be mapped to the Faculty's programme educational objectives and programme outcomes. The contents of the various courses comprising the programme have to be integrated to bring all the learning outcomes together and taught in a systematic approach to become a total system. In the project design, issues such as sustainable development, risk, health and safety, and professional ethics are areas of concern. This paper describes how IMechE's UK regulations and requirements are being met, and relates the Faculty's experience with the accreditation process.
Embedding Enterprise in Engineering
Authors: Handscombe Robert D. , Rodriguez-Falcon Elena , Patterson Eann A.
Published: February 2013

A great deal of enterprise teaching is carried out in business schools and has been for many years. The challenge of the UK's Science Enterprise Challenge was to extend enterprise teaching more thoroughly to science and engineering students. While some of the centres launched under the initiative developed the activity of business schools, there were notable exceptions. This paper focuses on the attempts to implement the challenges of teaching enterprise to engineering students in the Department of Mechanical Engineering at the University of Sheffield. This was one of the most successful departmental interventions of the White Rose Centre for Enterprise (WRCE), formed in 1999 as part of the UK Science Enterprise Challenge initiative. WRCE's remit, like that of the other science enterprise centres, was to increase enterprise learning and entrepreneurship, thus bringing about a ‘cultural change’ in those universities involved in the collaboration. WRCE's approach was to embed enterprise in the teaching programme of the science and engineering departments. The general propositions of WRCE are reviewed in the light of the activities within the Department of Mechanical Engineering. Some detailed qualifications of those propositions arise, with strong emphasis on the importance of pedagogic approaches and sequence of content.
The Production of a Microsoft Excel Tool to Assist in the Teaching of the Use of Venturi Tubes to Calculate Mass Flow Rates and Their Associated Uncertainties
Authors: Cooke Adam , Regan Nicholas
Published: February 2013

This paper describes the use of venturi tubes and the calculations involved in their use; it also introduces a new spreadsheet tool developed to assist in the teaching of the subject. The tool is easy to use and allows the user to calculate liquid or gas mass flow rates. This is done by the user entering the values of required variables and choosing the applicable units of measurement from embedded drop-down lists. Non-SI units can be selected, as the tool makes the necessary conversions within hidden cells and tabs. In addition to calculating mass flow rates, the tool also calculates their associated uncertainty. The tool can be used by lecturers as part of undergraduate teaching or by practising engineers who use venturi tubes or have an interest in them.
Developing a Course on Advanced Product Development for an Asia-Link Project
Authors: Tan Xincai , Yan Xiu-Tian , Juster Neal P. , Ion William J.
Published: February 2013

The Chinese economy has been growing rapidly, and well trained engineers are increasingly in demand for product development. Through an Asia-Link project, a short training course, Advanced Product Development, was delivered for the training of teaching staff from China. The course covered advanced design methods, skills and management, concurrent engineering, and project exercises. A post-course survey showed that the course contents were subsequently applied within teaching and research in China owing to the advanced contents covered in the teaching materials and research ideas.
A Trigonometrical Ratio to Replace the Dimensionless Angle in Radians
Authors: Clayton David G.
Published: February 2013

Equations for use with SI radian units have the option of showing the radian unit or not. When the radian is not shown, identical purely numerical values for angles (θ) are produced in each equation. This is the common procedure. When the radian is shown, not all the θ values can show a radian unit: some must remain as pure numbers. This procedure is used whenever convenient, usually for extra clarity. The article proposes that the constantly numerical values of θ be treated as trigonometrical ratios, currently recognised as the ‘radian measure’ or the ‘circular measure’ (abbreviated: circ) of angles, and replaced by ‘circ θ’. This measure equals the length ratio (subtended arc/radius) for an angle θ at the circle centre. By this means the need for the dimensionless version of ‘angle in radians’ vanishes. In fact even dimensional angles in radians need not be used, because ‘circ θ’ allows any angle units to be used for θ.
Improvement in Learning on Fluid Mechanics and Heat Transfer Courses Using Computational Fluid Dynamics
Authors: Zamora Blas , Kaiser Antonio S. , Vicente Pedro G.
Published: February 2013

This paper is concerned with the teaching of fluid mechanics and heat transfer on courses for the industrial engineer degree at the Polytechnic University of Cartagena (Spain). In order to improve the engineering education, a pedagogical method that involves project-based learning, using computational fluid dynamics (CFD), was applied. The project-based learning works well for mechanical engineering education, since it prepares students for their later professional training. The courses combined applied and advanced concepts of fluid mechanics with the basic numerical aspects of CFD, including validation of the results obtained. In this approach, the physical understanding of practical problems of fluid mechanics and heat transfer played an important role. Satisfactory numerical results were obtained by using both Phoenics and Fluent finite-volume codes. Some cases were solved using the well known Matlab software. Comparisons were made between the results obtained by analytical solutions (if any) with those reached by CFD general-purpose codes and with those obtained by Matlab. This system provides engineering students with a solid comprehension of several aspects of thermal and fluids engineering.
Learning Finite Element Methods by Building Applications
Authors: Kosasih P. B.
Published: February 2013

This paper describes how programming projects are used to help students understand the theory of finite element (FE) methods in the author's class. The implementation of FE theory in FE-based commercial software is made clearer through programming simple FE analysis codes. From the experience gained in the coding, students have a better understanding of the theory and numerical processes used in FE commercial software. As a result, they have more confidence in using commercial software, knowing that the computer programs are not simply ‘black boxes’ that process data and produce colourful results. More importantly, they understand the limitations of the programs, how to use them correctly and interpret the generated output correctly. Two projects are described in which students develop codes and then compare the results with those from commercial software.
Sharing of an in-Class Experience with Lagrange Equations of the First and Second Kind for Determining Reaction Forces
Authors: Gürgöze M. , Zeren S.
Published: February 2013

The current study deals with in-class observations made during the teaching of a graduate-level mechanical engineering course entitled ‘Dynamics of Mechanical Systems’. The specific discussion is about the students' various approaches to the application of Lagrange equations in the context of a homework assignment. The analytical solution requested from the class deals with the determination of the vertical component of the reaction force between a spherical pendulum and its hanging point.
Multifunctional Pilot Plant for Mechanical Engineers
Authors: Loccufier M. , Petit F.
Published: February 2013

Cross-course projects are very important in mechanical engineering curricula. Based on the dynamic response of a structure to a ground motion, a pilot plant for hands-on training has been developed which incorporates structural analysis, experimental modelling, mechanical vibration, servo control, signal processing, kinematics and dynamics of machinery.
On the Euler and Lagrange's Points of View in Rigid Body Mechanics
Authors: Martins Flavius Portella Ribas , Trigo Flávio Celso , de Toledo Fleury Agenor
Published: February 2013

In this work we take Lagrange's and Euler's important concepts from fluid mechanics and apply them to the movement of a rigid body. By means of two examples, namely motion around a fixed axis and around a fixed point, Lagrangian and Eulerian formulations of the problems are discussed. It is shown that Euler's approach suits better the description of rigid body kinematics, since the linearized equations of motion are simpler than the ones obtained by Lagrange's formulation. This topic is rarely discussed in undergraduate courses on mechanics but it can provide students with a deeper comprehension of the movement of a rigid body and, at the same time, establish a connection with the scope of fluid mechanics.
Mechanical Counterpart of an Electronic Transistor
Authors: Shai O. , Eliahou-Niv S. , Roman D. R. G. , Rubin D. , Slavutin M.
Published: February 2013

The paper introduces a mechanical counterpart of an electronic transistor, which exhibits same behavioral properties. Besides the practical contribution, this work gives an opportunity for students and engineers specializing in mechanical disciplines to learn and understand one of the basic elements in electronics through their knowledge in mechanics. The result reported in the paper enables the transformation of electronic systems into mechanical systems, with the related problems solved using mechanical knowledge, and then transferring the solution back to the terminology of electronics. Since a hydraulic device, a ‘valvistor’, analogous to a transistor, was developed a few years ago, the paper provides a general and unified perspective on this topic from the viewpoints of hydraulics, mechanics and electronics and can be used for inter-disciplinary education.