bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering Problem Solving: Learning and Practice
Authors: Bzymek Zbigniew M.
Published: October 2013

The Engineering Problem Solving process has two aspects. It relies on the talent of the designer on the one hand and the efficiency of the problem solving tools on the other. Talent is an attribute of a person. It is very difficult to formalize the talent of an individual, and no satisfactory formalization has been achieved successfully. For this reason only the original designer’s talent and his/her knowledge and experience are available for use during the problem solving process. However, there are several choices and decisions that can be made concerning methods, algorithms, and software packages. After those choices are made the next steps in the problem solving process can be outlined. The problem solving method described in this paper is called a Brief Theory of Inventive Problem Solving (BTIPS) and was developed on the basis of TRIZ (Russian: теория решения изобретательских задач, teoriya resheniya izobretatelskikh zadatch) and TIPS (Theory of Inventive Problem Solving) and taught at the University of Connecticut (UConn). The application of this method starts with the accurate definition of the problem. The problem has to be properly separated from the environment. Further problem solving choices depend on the knowledge of the designer and include the right sequence of steps, definition of contradictions, choice of solution modules, algorithms, definition of designed systems and subsystems, and choice of elements and objects. There are several further paths to be selected and resulting decisions to be made. Those decisions and the processes following them are described in this paper. The recommendations for the proper path are given and the procedures are discussed. The derivation of the Ideal Solution is described and tests of the solution’s effectiveness and economy are given. The experience gained from teaching one Mechanical Engineering course, three MEM (Management Engineering for Manufacturing) courses at UConn, one graduate course at UConn, one graduate course at the University of Fairfield, and several special non-academic courses for practicing engineers is summarized. Some students’ opinions are analyzed and recommendations for further education and the practice of engineering problem solving are derived. The references to the existing teaching, research, practice, and development studies are quoted. This paper is devoted to the characteristics of BTIPS method. The companion paper [1] is devoted to the characteristics of the software that could be used with the method. TIPS (the Theory of Inventive Problem Solving) is a further development of Altshuller’s theory done by Invention Machine under the leadership of Valery Tsourikov [2]. BTIPS (Brief Theory of Inventive Problem Solving) is a simplified version of TIPS developed at the University of Connecticut (UConn) especially for teaching purposes, though it is also powerful when applied to engineering practice problems [3].
Connecting Chain Chemistry and Network Topology With the Large Deformation Mechanical Response of Elastomers
Authors: Davidson Jacob D. , Goulbourne N. C.
Published: October 2013

Elastomers are polymers able to undergo large, reversible deformations, and their mechanical properties depend on the chemistry of individual chains as well as the topology of the crosslinked network. In this work we analyze the connection between micro-scale network structure and the macroscopic mechanical properties by performing molecular dynamics (MD) simulations using the Kremer & Grest bead-spring model. The chain length and the density at which crosslinking is performed are varied in order to produce systems ranging from crosslink-dominated to highly entangled, and stress-stretch results are obtained via MD in the large deformation regime. In analogy with recent work on social, technological, and biological networks, we apply mathematical graph theory to describe elastomer networks in a multi-scale modeling framework. A matrix formulation of crosslinked polymers is presented and applied in order to identify the network structure resulting from both chemical crosslinks and physical crosslinks (entanglements). We show that spectral analysis of the crosslink and chain entanglement adjacency matrices along with the corresponding degree distributions can be used to identify and differentiate between the different materials. The spectrum of the crosslink adjacency matrix resembles a sparse regular graph, and spectrum of the intermolecular chain entanglement matrix for the highly entangled systems is shown to resemble a random graph; however, deviations are noted which require further study. A comparison of the network properties with the stress-stretch response demonstrates the influence of both crosslinks and entanglements on the large deformation mechanical behavior of an elastomer material.
Design of a Horizontal Axis Wind Turbine for Fiji
Authors: Goundar Jai N. , Narayan Sumesh , Ahmed Mohammed Rafiuddin
Published: October 2013

The demand and cost of electricity has increased for Pacific Island Countries (PICs). The electricity from main grid does not reach rural areas and outer islands of Fiji. They burn fuel for electricity and daily lighting. Therefore, there is a need to look for alternative energy sources. Wind turbine technology has developed over the past years and is suitable for generating electricity by tapping wind energy. However, turbines designed to operate at higher wind speed do not perform well in Fiji, because Fiji’s average wind velocity is around 5–6 m/s. A 10 m, 3-bladed horizontal axis wind turbine is designed to operate at low wind speed, cut in speed of 3 m/s, cut off speed of 10 m/s and rated wind speed of 6 m/s. The blade sections were designed for different locations along the blade. The airfoil at the tip (AF0914) a has maximum thickness of 14% and maximum camber of 9%; the thickness varies linearly to the root, at the root the airfoil (AF0920) has a maximum thickness of 20% and maximum camber of 9%. The aerodynamic characteristics of airfoil AF0914 were obtained using Xfoil and were validated by experimentation, at turbulence intensities (Tu) of 1% and 3%, and a Reynolds number (Re) of 200,000. The aerodynamic characteristics of other airfoils were also obtained at operating Re at the turbulence intensities of 1% and 3%. These airfoils have good characteristics at low wind speed, and were used to design the 10 m diameter 3-bladed HAWT for Fiji. The turbine has a linear chord distribution for easy manufacturing purpose. Twist distribution was optimized using Blade Element Momentum (BEM) theory, and theoretical power and turbine performance were obtained using BEM theory. At the rated wind speed of 6 m/s and a TSR of 6.5, the theoretical efficiency of the rotor is around 46% and maximum power is 4.4 kW. The turbine has good performance at lower wind speeds and is suitable for Fiji’s conditions.
Carbon Nanotube Modified Electrically Conductive Cellulose Film
Authors: Jiang Wei , Hao Ayou , Li Wei , Chen Jonathan
Published: October 2013

In recent decades, the energy resource and environment pollution is becoming a main challenge for the sustainability of global economic development as a result of population growth and industrial development. Costs of the synthetic materials are rising due to the short supply of fossil oil. Meanwhile the synthetic materials are not biodegradable and renewable. So the materials with biodegradable and renewable properties need to be investigated. With an annual yield of about 7 × 1011 tones, cellulose is the Earth’s most abundant natural organic material [1]. Many methods and chemicals have been developed to process cellulose into different products [2–6].
Identification of a Transversely Isotropic Material Model for White Matter in the Brain
Authors: Feng Yuan , Okamoto Ruth J. , Namani Ravi , Genin Guy M. , Bayly Philip V.
Published: October 2013

Axonal fiber tracts in white matter of the brain form anisotropic structures. It is assumed that this structural anisotropy causes mechanical anisotropy, making white matter tissue stiffer along the axonal fiber direction. This, in turn, will affect the mechanical loading of axonal tracts during traumatic brain injury (TBI). The goal of this study is to use a combination of in-vitro tests to characterize the mechanical anisotropy of white matter and compare it to gray matter, which is thought to be structurally and mechanically isotropic. A more complete understanding of the mechanical anisotropy of brain tissue will provide more accurate information for computational simulations of brain injury.
Fluid Damping and Power Consumption of Active Devices Used in Cooling Electronics
Authors: Huang Longzhong , Agrawal Smita , Simon Terrence , Zhang Min , Yeom Taiho , North Mark , Cui Tianhong
Published: October 2013

Active devices, such as synthetic jets and oscillating plate agitators were found to be effective in cooling of high-heat-flux electronics. These devices generate unsteady flows, thinning the thermal boundary layer and enhancing turbulent transport. However, the active devices cause extra power consumption due to flow friction and separation. It is important to understand the factors influencing power consumption in these devices if they are to be applied in cooling system designs. The present study analyzes fluid damping and power consumption in high-frequency (about 1000 Hz) synthetic jets and oscillating plate agitators driven by piezoelectric stacks. This analysis is done numerically, since it is difficult to measure fluid damping. In the simulations, the moving part of the active device is modeled with the moving wall boundary condition. The mesh is updated and the flow is calculated every time the moving part changes its position. The coherent vortex structures generated by theses active devices, like vortices in the synthetic jet cavity or in the oscillating plate tip gap region, are found to cause fluid damping and power consumption. Fluidic power consumption levels with different geometries and different operating frequencies and amplitudes are studied. A correlation is developed to predict fluidic power consumption at different operating conditions.
Numerical Analysis to Lead Free Solder/Intermetallic Interconnect With Application of Wiedemann-Franz-Lorenz Relation
Authors: Yao Yao , Fry Jared , Fine Morris , Keer Leon
Published: October 2013

Due to the limitation of available experimental data for thermal conductivity of lead free solder and Intermetallic Compound (IMC) materials, the Wiedemann-Franz-Lorenz (WFL) relation is presented in this paper as a possible solution to predict thermal conductivity with known electrical conductivity. The method is based upon the fact that heat and electrical transport both involve the free electrons. The thermal and electrical conductivities of Cu, Ni, Sn, and different Sn rich lead free solder and IMC materials are studied by employing the WFL relation. Generally, the analysis to the experimental data shows that the WFL relation is obeyed in both solder alloy and IMC materials especially matches close to the relation for Sn, with a positive deviation from the theoretical Lorenz number. Thus, with the available electrical conductivity data, the thermal conductivity of solder and IMC materials can be obtained based on the proper WFL relation, vice versa. With the reduction of size of electronic devices and solder interconnects, it has been observed experimentally that solders fail by crack nucleation and propagation near the interface of IMC and bulk solder. A coupled thermal-electrical finite element analysis is performed to study the behavior of lead free solder/IMC interconnects under different electrical current densities. The joule heating, temperature concentration and electrical current concentration effects with a crack propagating near the interface of solder and IMC are investigated numerically. Solder and IMC material properties predicted using the WFL relation are adopted in the computational model. The effects of different thermal and electrical conductivities of solder and IMC materials on interfacial crack tip temperature are analyzed in the present study. By applying the WFL relation, the amount of experiments required to determine the material properties for different lead free solder/IMC interconnects can be significantly reduced, which can lead to pronounced saving of time and cost.
Experimentally Validated Finite Element Analysis of Railroad Bearing Adapter Operating Temperatures
Authors: Zagouris Andoni , Fuentes Arturo A. , Tarawneh Constantine M. , Kypuros Javier A. , Arguelles Andrea
Published: October 2013

Currently, railroad bearing temperatures are monitored using wayside infrared devices known as hot-box detectors (HBDs). HBDs take a snapshot of the bearing temperature at designated wayside detection sites which, depending on the track, may be spaced as far apart as 65 km (∼40 mi). Even though these devices have significantly reduced the number of derailments since their implementation, their discrete nature and limited accuracy prevents them from being utilized as a bearing health monitoring system. Future technologies are focusing on continuous temperature tracking of bearings. Since placing sensors directly on the bearing cup is not feasible due to cup indexing during service, the next logical location for such sensors is the bearing adapter. Understanding the thermal behavior of bearing adapters during operation is essential for sensor selection and placement within the adapter (e.g., typical temperature sensors have operating ranges of up to 125°C). To this end, this paper quantifies the steady-state heat transfer to the bearing adapter through a series of experiments and finite element analyses. The commercial software package ALGOR 20.3™ is used to conduct the thermal finite element analyses. Different heating scenarios are simulated with the purpose of obtaining the bearing adapter temperature distribution during normal and abnormal operating conditions. This paper presents an experimentally validated finite element thermal model which can be used to attain temperature distribution maps of bearing adapters in service conditions. These maps are useful for identifying ideal locations for sensor placement.
Building Energy Scenarios for Large Water Pumping Systems
Authors: Gil Samaniego Ramos Margarita , Campbell Ramírez Héctor Enrique
Published: October 2013

The life quality of the world’s population and its development activities mainly depend on the availability, quantity and quality of fresh water. Water scarcity at many regions around the globe present challenges towards improving efficiency and rationalizing its use. The state of Baja California, México, is located at the northwestern corner of Mexico at a large semiarid region where rain incidence is very low (169 mm annually); thus, its water provision is also scarce. Federal and state governments have made efforts to guarantee water accessibility to its municipalities. The Río Colorado-Tijuana Aqueduct (ARCT) is a large water supply system that provides 5.33 m3/s of water to these cities. Its 6 pumping stations elevate the water 1,061 m through 147 km of pipes, canals and tunnels, and its total installed motor capacity is of 106,000 HP.

Pumps are high energy consumers and represent a large fraction of operating costs in water supply systems. The volume pumped by the ARCT in 2010 was of 80.7 million of m3, while consuming 322.7 GWh annually at a cost of 23.8 million dollars. Implementing actions for the saving and efficient use of energy in hydraulic facilities is a worldwide priority to achieve rational water management and therefore national and regional sustainable development. Methodologies that improve energy savings while satisfying system performance criteria should be sought for better performance and management of the water supply systems.

For building energy scenarios for such systems, it is necessary to integrate and adapt different methodologies for the simulation and assessment of behavior and performance taking in account hydraulic, electric and economic issues. This paper presents different approaches and results when these methodologies are applied for the case of ARCT.
Study of Flow Field Variables in a Pressure Reducing Valve
Authors: Adhikari Param , Panta Yogendra M. , Reppert Benjamin
Published: October 2013

Pressurized water valves are required in industrial applications ranging from steel industries to manufacturing plants where cooling is highly required. High water pressures are the most common requirement to descale oxide layers formed during steel production. The water passes through pumps, piping systems and valves before it flows out through nozzles. Such a high pressure requirement is generated from pumps and regulated by means of valves. The directional checking and ON-OFF regulation are the major jobs a valve should perform satisfactorily. The fluid properties are governed by mass, momentum and energy conservation as defined by Continuity, Navier-Stokes and Energy equation. The high pressure drop along the neck of the venturi induces cavitation problems which lead to failure over time.

Variation of several fluid properties like pressure, wall shear stress can be seen as the fluid flows through the valve. The high pressure fluid at the upstream region goes through the downstream region from the nozzle when the given valve allows to exit. The sharp bends and turns inside the valve causes several properties of water to change throughout its flow domain. The failure being observed on a high pressure water flow passage on a specific geometrical cross section from one of the local companies will be evaluated from the computational analysis. Lately, a baffle system was modeled in 2D as one of the capstone design projects for an undergraduate student. The main objective of this system was to attain a pressure drop within the channel to prefill all the pipes and valves connected along the line so that sudden descaling high pressure would not burst the air along the pipe. No pressure based density variation was employed in this study. The wall shear stress computed using ANSYS Fluent code was found to be max where the actual failure had occurred. It has been noted that no pressure based density variation was employed in this study.
Thermal Interaction Between a Circular Pipe and Diesel Pool Fire
Authors: Sudheer S. , Prabhu S. V.
Published: October 2013

Characterization of pool fires in the presence of cylindrical containers is highly relevant for various applications. A cylindrical container is idealized as a circular pipe packed with insulating material inside. Open pool fire experiments are conducted with a cylindrical container located at the center. The pool fire diameters considered were 0.5 m, 0.7 m and 1.0 m with diesel as the fuel. The cylindrical containers are made of stainless steel 304L. The outer diameters of the pipes are 114 mm, 168 mm and of thickness 8.6 mm, 7.1 mm respectively. The effect of blockage ratio on the mass burning rate for vertical and horizontal orientations of 168 mm cylindrical container is studied. It is observed that there is no significant change in mass burning rate due to the blockage effect. Temperatures are measured at various locations inside the pipes and at the center of the insulation. It is observed that the temperatures along a plane perpendicular to the axis are uniform when the pipes are vertically oriented. IHCP 1D code is applied to estimate the incident heat flux on to the bodies when immersed in open pool fires with different orientations.
Development of Two-Dimensional Bubble Movement and Development Benchmark Dataset for Numerical Validation
Authors: Keshavarzi Gholamreza , Barber Tracie J. , Yeoh Guan
Published: October 2013

The motion and transport of bubbles in fluid flows have many engineering applications. The rise of a bubble has been a point of interest for both numerical and experimental studies. Various tracking methodologies have been developed, including markers, level sets and volume tracking. In order to validate numerical models of bubble flow, detailed experimental data describing the transient bubble shape is needed. This is best found from a 2D comparison rather than 3D experiment because computational resources for determining an accurate shape can be maximized. No real full time shape and subsequent deformation of this 2D bubble has yet been demonstrated. In this paper 2D bubble experiments have been conducted, in which a single bubble has been injected inside a close-walled tank and the rising of the bubble has been captured through a high speed camera. This data is now being used as a benchmark for numerical interface capturing and two phase flow methodology validations.
A Sensor Model for Enhancement of Manufacturing Equipment Data Interoperability
Authors: Lee Kang B. , Song Eugene Y. , Gu Peter S.
Published: October 2013

Sensors can provide real-time production information to optimize manufacturing processes in a factory. Recently, more attention has been paid to the application of sensors in smart manufacturing systems. Sensor data exchange, sharing, and interoperability are challenges for manufacturing equipment monitoring in smart manufacturing. Standardized sensor data formats and communication protocols can help to solve these problems. MTConnect is an open, free, extensible protocol for the data exchange between monitoring applications and shop floor devices which include machine tools, sensors, and actuators. This paper introduces a sensor model for MTConnect to enhance manufacturing equipment data interoperability. The sensor model defines a Sensor and SensorChannel, as well as an interface to access the Sensor and its SensorChannels, which include sensing element, calibration, signal conditioning, and analog-to-digital conversion (ADC) information. The sensor model has been implemented in a virtual milling machine with a built-in sensor. Two case studies of MTConnect Probe and Sample requests for sensor information are provided to verify the sensor model.
Vibration Characteristics of a Human Adult and Infants Travelling in a Bicycle With Two Child Seats
Authors: Ota S. , Nishiyama S. , Shinohara T.
Published: October 2013

This paper describes the vibration characteristics transmitted from the road to the human body when riding a bicycle with two child seats. To examine the vibration characteristics for the bicycle, human body, and infants, we developed a system for measuring the vertical vibrations using acceleration sensors and infant dummies as a substitute for real infants. In an experiment on the transient response, subjects rode over three different types of lugs at a constant velocity. In an experiment on the frequency response, subjects were vibrated by a vibration exciter. The experimental results clarified the vibration characteristics of a bicycle–occupant–system.
Biomechanical Assessment of the Bridging Vein Rupture of Blast-Induced Traumatic Brain Injury Using the Finite Element Human Head Model
Authors: Wang Chenzhi , Pahk Jae Bum , Balaban Carey D. , Muthu Joseph , Vorp David A. , Miller Mark C. , Vipperman Jeffrey S.
Published: October 2013

The incidence of the blast-induced traumatic brain injury (bTBI) among American troops in battle environments is dramatically high in recent years. Shock wave, a production of detonation, is a brief and acute overpressure wave that travels supersonically with a magnitude which can be several times higher than atmospheric pressure. Primary bTBI means that human exposure to shock wave itself without any other impact of solid objects can still result in the impairment of cerebral tissues. The mechanism of this type of brain injury is different from that of the conventional TBI, and has not been fully understood. So far, it is believed that the shock wave transmitted through skull and into cerebral tissues may induce specific injury patterns. This study is trying to develop a methodology to numerically investigate the mechanism of the blast-induced subdural hematoma (bSDH), which is caused by bridging vein rupture. The effort of this study can be divided to three major parts: first, a finite element (FE) model of human head is developed from the magnetic resonance imaging (MRI) of a real human head to contain skull, CSF and brain. Numerically simulated shock waves transmits through the human head model whose mechanical responses are recorded; second, in order to obtain the mechanical properties of human bridging vein, an standard inflation test of blood vessels is conducted on a real human bridging vein sample gained from autopsy. Material parameters are found by fitting the experimental data to an anisotropic hyperelastic constitutive model for blood vessel (Gerhard A. Holzapfel 2000); third, The bridging vein rupture in bTBI is evaluated by the finite element analysis of a separate human bridging vein model under the external loadings in terms of the internal pressure and relative skull-brain motion which are extracted from the mechanical response of the subarachnoid space of the head in the blast-head simulation of the first part.
Motion Analysis of Weaving “Kana-ami” Technique With Different Years of Experience
Authors: Tsuji Ken-ichi , Narita Chieko , Endo Atsushi , Takai Yuka , Goto Akihiko , Sasaki Gen , Ohta Tomoko , Hamada Hiroyuki
Published: October 2013

The technique of making “KANA-AMI” is traditional craftsmanship in Kyoto. All wire net fabrications are made by the hand work, so that it is expected that the craft man has the exquisiteness of motion. The purpose of this study is to clarify the characteristics of motion during the weaving the wire nets with different years of experience.

The subjects were three males whose have experienced wire netting craftsman for 44 years, 8 years and 0 years respectively. The working environment was reproduced in the laboratory so that the subjects might work usual like working environment as much as possible and they could concentrate on them work. The infrared reflection markers were affixed at 21 points on the body of the craftsman to analyze motion during the wire netting. And six cameras (hawk-i Motion Analysis Co. Ltd.) captured the position of each marker, and all markers position data which synchronized were taken in by a computer (sampling rate: 100Hz). It was defined that right to left direction was X axis, front to rear direction was Y axis, top to bottom direction was Z axis for subjects. In addition, shape and degradation of wire net were evaluated. The shapes of hexagonal pattern were evaluated. Degradation of wire nets were evaluated by salt spray tests.
Heat Transfer Enhancement Across a Pair of Confined Cylinders Using Improved Particle Swarm Optimization Algorithm
Authors: Nejat Amir , Mirzabeygi Pooya , Shariat-Panahi Masoud , Mirzakhalili Ehsan
Published: October 2013

The dissipation of the heat generated by electronic devices is the key issue in design and development of such products. The trend, especially in the computer industries, has been reducing the size and increasing the computing power of the electronic elements. Studies have indicated that the thermal performance of a micro-channel depends on its geometric parameters and flow conditions. Many techniques have been developed to enhance the performance of confined elliptical cylinders while minimizing the momentum loss. In this paper, a new robust optimization technique is presented. This new technique is an improved Particle Swarm Optimization (PSO) algorithm in which diversity is actively preserved by avoiding overcrowded clusters of particles and encouraging broader exploration. Adaptively varying “territories” are formed around promising individuals to prevent many of the lesser individuals from premature clustering and encouraged them to explore new neighborhoods based on a hybrid self-social metric. Also, a new social interaction scheme is introduced which guided particles towards the weighted average of their “elite” neighbors’ best found positions instead of their own personal bests. The case study in this paper is a two dimensional incompressible flow of non-Newtonian power-law fluid over a pair of elliptical tandem cylinders confined in a channel. A new curve parameterization named Class-Shape-Refinement-Transformation method is used to modify the shape of the confined cylinders, and its control points are adopted as the design variables. Furthermore, final solutions obtained from the Territorial Particle Swarm Optimization algorithm reveal an evident improvement over the test case cylinder across all objective functions presented.
Adaptive Electromagnetic Torsional Tuned Vibration Absorber and its Application in Rotating Equipment
Authors: Seer Taher Abu , Vahdati Nader , Karki Hamad , Shiryayev Oleg
Published: October 2013

Rotating equipment is susceptible to torsional vibrations whenever the RPM of the rotating equipment matches one of the torsional natural frequencies. For rotating equipment running at constant RPM, it is easy to control and mitigate the torsional vibrations, but in applications where the RPM is no longer a constant and varies widely or natural frequencies are changing: there is a need for a wide range vibration reduction device.

In this paper, a translational adaptive electromagnetic tuned vibration absorber (ETVA) is described where its natural frequency is varied using electronics. The ETVA is modeled and its simulation results correlate very well with experimental results. Later, this concept is used to develop a torsional tuned vibration absorber (TTVA) device. The electromagnetic TTVA can be attached to rotating equipment to control torsional vibrations. The electromagnetic TTVA adapts itself and controls the torsional vibrations as and when the RPM varies. Here in this paper, the rotating equipment and the electromagnetic TTVA are modeled. Analysis results indicate that the torsional vibration of rotating equipment can be easily controlled using this newly developed electromagnetic TTVA.
Investigation of Early Dry and Wet/Dry Cooling Studies
Authors: Bamberger Judith Ann
Published: October 2013

In mid 1974, The U.S. Atomic Energy Commission initiated the Dry Cooling Tower Program to provide the technology to support the increased use of dry cooling for central power stations. The purpose of the program was to provide solutions to existing problems of dry cooling and the development and demonstration of new dry cooling concepts. The program included input from utilities, architect engineers, dry cooling system vendors and others involved in technology development. This paper focuses on initial studies conducted at Pacific Northwest National Laboratory to investigate dry and wet/dry cooling concepts to develop economic and performance models for cost optimization of total heat rejection systems using dry and wet/dry cooling to provide a compilation of studies and results.
A Global Experiential Design Studio for Engineering Students
Authors: Verstraete Dries , Wong K. C. , Lehmkuehler Kai , Netzel Thomas , Hendrick Patrick
Published: October 2013

The growing trend of global, multi-company collaboration within the engineering community has led to a changed work environment where new graduates must function under constraints that include global, cultural, and business contexts as part of the new engineering “fundamentals”. The classical “engineering science” education model lacks opportunities for students to gain experience that prepares them for this new work environment. To provide learning opportunities that will enhance the global communication and intercultural collaboration skills of engineering students, a pilot project for providing some goal-directed learning space was set up as a global experiential learning design studio in aeronautical engineering. During this project, engineering teams spread across the globe are designing, building and testing innovative blended wing body UAV airframes. The lessons learned from this pilot project are intended to generate a template that can effectively be used across different disciplines of engineering. This paper describes the education initiative and the accomplished designs. It additionally reports on experiences and lessons learned to date, and steps taken to improve the learning outcomes and graduate attributes, to enhance global team collaboration skills.
A New Targeting Method for Combined Heat, Power and Desalinated Water Production in Total Site
Authors: Khoshgoftar Manesh Mohammad Hasan , Ghalami Hooman , Khamis Abadi Sajad , Amidpour Majid , Hamedi Mohammad Hosein
Published: October 2013

Low-grade heat is available in large amounts across process industry from temperatures of 30 °C to 250 °C as gases (e.g. flue gas) and/or liquids (e.g. cooling water). Various technologies are available for generating, distributing, utilizing and disposing of low grade energy. Also, conventional desalination technologies are energy intensive and if the required energy hails from fossil fuel source, then the freshwater production will contribute to carbon dioxide emission and consequently global warming. In this regard, low grade heat source can be very useful to provide energy to the heat sink by upgrading low-grade energy (e.g. low pressure steam). The upgrade of low grade heat can be carried out by desalination technologies by recovering waste heat from various sources. The steam network of site utility system has a suitable potential for production of low grade heat. Estimation of cogeneration potential prior to the design of the central utility system for site utility systems, is vital to set targets on site fuel demand as well as heat and power production. So, a new cogeneration targeting model has been developed for integration of steam desalination systems and site utility of process plant. The new procedure to find optimal integration has been proposed based on new cogeneration targeting. In this paper, evaluation of coupling different desalination systems which includes multi-stage flash (MSF), multiple effect distillation (MED), membrane reverse osmosis (RO), and hybrid (MSF/MED-RO) to steam network of site utility system with have been considered. The integration of desalination systems to a low grade heat source has been performed using proposed cogeneration targeting method. In addition, a modified Site Utility Grand Composite Curve (SUGCC) diagram is proposed and compared to the original SUGCC. A steam network of process utility system has been considered as a case study.
Fuzzy Modeling of a Nonlinear Continuous Fermentation Bioreactor for Ethanol Production
Authors: Díaz Jácome Alfredo , Sanjuan Marco
Published: October 2013

Ethanol production from glucose was analyzed implementing fuzzy techniques to investigate and model the nonlinear behavior of the process. The model simulated involves the basic equations of a chemostat including the dependence of kinetics parameters on temperature and mass transfer of oxygen. For the identification of nonlinearities. Steady-state values for inlet temperature, the flow of refrigerant and the initial concentration of substrate are 25 ° C, 18 L / h and 60 g / L glucose, respectively. The implementation of the Fuzzy Inference System (FIS) was based on a Mamdani inference engine, and also that the defuzzification method implemented was centroid and the weight of the trapeziums describing the output from 15 to 30 g/L affects considerably. After evaluating and comparing the results of the simulation with FIS results, and calculating the correlation between Predicted and Expected values, it is concluded that correlation factor for the entire simulation and FIS was around 0.9. The lack of fitness is evaluated and analyzed after the comparison of results.
Real-Time Fault Detection Application for Natural Gas Pipelines
Authors: Torres Melitsa J. , Posada Jose D. , Garcia Jaime R. , Sanjuan Marco E.
Published: October 2013

The implementation of fault detection techniques in industrial systems for process monitoring has proven to be a useful tool to process operators supervising the plant’s operation conditions. As plants become more instrumented, more data is available for fault detection applications, if they are capable of demonstrate anticipation and low false alarm rates. A regional Natural Gas transportation system deals with these types of drawbacks. While the improvements are carried out, some effort should be done in order to improve the safety in operations. In this paper a data-driven technique was used to detect fault conditions along the pipeline, sectioning it in five partitions to increase the detection sensibility. To overcome the lack of quality in data, simulation software intended to gas controllers training and pipeline operation was used to simulate leaks scenarios. Some historic data with high quality is also used to create normal operation condition models by means of Principal Component Analysis. All simulated faults were detected in a reduced time gap and recent events related to third-party actions showed the tool proficiency to detecting faults in real time. In addition, it considers a fault normalized index per section indicating the fault persistence and aggressiveness in a single plot.
Three Dimensional Dynamic Analysis of a Piezoelectric Valveless Micropump: Effects of Working Fluid
Authors: Sayar Ersin , Farouk Bakhtier
Published: October 2013

Coupled structural and fluid flow analysis of a piezoelectric valveless micropump is carried out for liquid transport applications. The valveless micropump consists of trapezoidal prism inlet/outlet elements; the pump chamber, a thin structural layer (Pyrex glass) and a piezoelectric element (PZT-5A), as the actuator. Two-way coupling of forces and displacements between the solid and the liquid domains in the systems are considered where actuator deflection and motion causes fluid flow and vice-versa. Flow contraction and expansion (through the trapezoidal prism inlet and outlet respectively) generates net fluid flow. The pressure, velocity, flow rate and pump membrane deflections of the micropump are investigated for six different working fluids (acetone, methanol, ethanol, water, and two hypothetical fluids). For the compressible flow formulation, an isothermal equation of state for the working fluid is employed. Three-dimensional governing equations for the flow fields and the structural-piezoelectric bi-layer membrane motions are considered. Comparison of the pumping characteristics of the micropumps operating with different working fluids can be utilized to optimize the design of MEMS based micropumps in drug delivery and biomedical applications.
Examination of the Ability of Conceptual Airbag Systems to Affect Restrained Occupant Kinematics and Associated Neck Loads During Rollover Impact Conditions
Authors: Friedman Keith , Hutchinson John , Mihora Dennis
Published: October 2013

Rollover occupant protection systems consist of many design elements such as various seat belt types, airbags, active and passive seats, and deployable systems in rollover impacts. In this study conceptual airbag systems intended to modify occupant kinematics were examined. The potential effects of these systems on occupant neck loads were evaluated. Finite element models of an LTV type vehicle and a 50th percentile dummy were utilized to evaluate the effects of alternative designs on neck loads under example rollover conditions. CAE representations of deployable airbag system types were created. Results of the study are summarized below.
Development of Test Protocol to Analyze Low Back Motion
Authors: Soman Varun , Gudavalli Maruti Ram , Raju P. K. , Marghitu Dan
Published: October 2013

The aim of the study was to quantify stability of low back spine using traditional and non-linear methods. Nine healthy volunteer subjects were recruited for the study using word of mouth and screened for eligibility by licensed clinicians. Participants performed 10 cycles of flexion-extension, lateral bending and rotation motion against no resistance, 22N, 45N and 67N resistance. Motion data was recorded at a frequency of 120 Hz for each exertion and for each resistance. Range of Motion (ROM), Correlation Dimension (CoD), Approximate Entropy (ApEn) were used to analyze the motion data. It was seen from results of both traditional and non-linear methods that stability was not affected significantly with the increasing load. Gradual increase in load and the pace at which the exercise cycles were carried out might be some of the reasons.
Enhancing Supercritical Fluid Extraction Using Acoustic Excitations
Authors: Hasan Nusair , Farouk Bakhtier
Published: October 2013

A computational fluid dynamics model of supercritical fluid extraction of a solute (caffeine) from a fixed bed of porous solid matrix (coffee beans) using a supercritical solvent (carbon dioxide) is developed. The mathematical model is developed considering diffusion-controlled transport in the particle and film mass transfer resistance around the particle. Accurate representations of the transport properties of supercritical carbon dioxide are considered. The conservation equations are numerically solved using an implicit finite volume method. Supercritical fluid extraction of a solute from a solid matrix has a slow dynamics even when solute free solvent is re-circulated and therefore improvements in the mass transfer process are required. The effect of acoustically excited flows on supercritical fluid extraction in a fixed bed extractor is investigated. Harmonically oscillating inlet wall boundary condition is used to model a piezoelectric transducer. The use of acoustic excitation represents a potential efficient way of enhancing mass transfer processes. Application of acoustic excitations at the fundamental frequency of the extractor (f = 996 Hz) increased the overall yield by about 15%. The effects produced by compressions and decompressions, as well as by radiation pressure and streaming contribute to the enhancements.
Side Impact Performance of Structurally Integrated Space Frame Doors
Authors: El-Sayed Mohamed E. M.
Published: October 2013

About 8,000 fatalities and 69,000 serious to critical injuries occur in side impacts every year in U.S. Severe head trauma and spinal cord injuries are directly related to the extent of penetration or intrusion into the occupant’s space. In side impact crashes, lack of a strong side structure reduces the ability of the impacted vehicle to safely respond to the impacting vehicle or object. This structural weakness causes massive injuries to the occupant due to the excessive side intrusion. With the increasing number of larger and heavier vehicle such as SUVs on the road and the higher probability of being impacted by one, the need for side impact protective measures is becoming more critical.

The main difficulty in designing for side impact collisions is the limited structure and energy absorption zone between the impacting vehicle and the impacted occupant. This paper discusses side impact occupant safety of space frame doors and their integration with vehicle body structure. The main objective is to explore the effect of space frame doors utilization on side intrusion and occupant response criteria. To study the effect, side impact crash tests of un-integrated and integrated space frame doors, with the vehicle body structure, are conducted.
A New Ballistic-Diffusive Model for Heat Pulse Propagation
Authors: Ma Yanbao
Published: October 2013

In this paper, we reported a new ballistic-diffusive model for heat pulse propagation in dielectric materials. The internal energy and heat flux are split into ballistic part originating from the boundaries and diffusive part originating from inside medium. The ballistic part is modeled based on analytical solutions while the diffusive part is described by Guyer-Krumhansl equations. To validate this model, heat pulse propagation in pure NaF at low temperature is studied. The observed longitudinal waves, transverse waves, second sound waves, and diffusive waveforms from the experiments conducted in early 1970s are numerically reconstructed. There is qualitative agreement between numerical results and experimental observation.
Architectural and Performance Integration of Hybrid Vehicles
Authors: El-Sayed Mohamed E. M.
Published: October 2013

With the development of advanced propulsion systems such as hybrid the need for new system integration, development, and validation strategies increases. Traditional methods for development and validation of vehicles focused mostly on the mechanical systems. Considering that the majority of architectural and performance issues arise from the different interfaces, the complexity increases when these interfaces are of different types such as electro-mechanical and electro-chemical etc.

In this paper, some architectural and performance integration issues arising from vehicle electrification and the development of advanced propulsion systems will be studied. To demonstrate the issues and illustrate their impact on the vehicle development process some hybrid system development examples are discussed.
Aeroderivative Combined Heat and Power Fundementals and Applications
Authors: DiCampli James
Published: October 2013

Combined heat and power (CHP), is an application that utilizes the exhaust heat generated from a gas turbine and converts it into a useful energy source for heating & cooling, or additional electric generation in combined cycle configurations. Compared to simple-cycle plants with no heat recovery, CHP plants emit fewer greenhouse gasses and other emissions, while generating significantly more useful energy per unit of fuel consumed. Clean plants are easier to permit, build and operate.

Because of these advantages, Aeroderivative gas turbines will be a major part of global CHP growth, particularly in China. In order to improve energy efficiency and reduce CO2 emissions, China is working to build ∼1000 new plants of Natural Gas Distributed Energy System (NG-DES) in the next five years. These plants will replace conventional coal-fired plants with combined cooling, heating and power (CCHP) systems. China power segments require an extensive steam supply for cooling, heating and industrial process steam demands, as well as higher peak loads due to high population densities and manufacturing growth rates.

GE Energy Aero recently entered the CCHP segment in China, and supported the promotion of codes and standards for NG-DES policy, and is developing optimized CCHP gas turbine packages to meet requirements. This paper reviews those policies and requirements, and presents technical case studies on CCHP applications. Appendix B highlights China’s draft “Guidance Opinions on Developing Natural-Gas Distributed Energy.”
Mitigation of Pore Generation in Laser Welding of Magnesium Alloy AZ31B in Lap Joint Configuration
Authors: Harooni Masoud , Kong Fanrong , Carlson Blair , Kovacevic Radovan
Published: October 2013

Magnesium, as the lightest structural metal, has been widely used in the automotive and aerospace industries. Porosity is the main issue in the welding of magnesium alloys and can be caused by surface coatings, hydrogen gas, pre-existing porosity, the collapse of an unstable keyhole and vaporization of alloying elements. In this study, the effect of the oxide layer on pore generation in the welding of AZ31B-H24 magnesium alloy is investigated. A fiber laser with a power of up to 4 kW is used to weld samples in a lap joint configuration. Two groups of samples are studied: as received (AR) surfaces (where an oxide layer remains on the surface) and treated surfaces. The surface treatment includes two techniques: mechanical removal (MR) and the use of a plasma arc (PA) as a preheating source. Also, a separate set of experiments are designed for preheating samples in a furnace in order to investigate whether the pore mitigation effect of a plasma arc is caused by preheating. Observations include a weld bead profile achieved through optical microscopy, chemical compositions tested by Electron Dispersive Spectroscopy (EDS), and mechanical properties measured with a tensile test. The results obtained show that the preheating effect of a plasma arc procedure can effectively mitigate pore generation. The tensile-shear results reveal that PA samples have a higher strength than other groups of samples.