bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strengths and Limitations of Advanced Exergetic Analyses
Authors: Morosuk T. , Tsatsaronis G. 
Published: April 2014

The exergetic analysis is a powerful tool for developing, evaluating and improving an energy conversion system.
The strengths and limitations of the so-called conventional exergetic analysis have already been discussed. An advanced exergetic analysis can significantly reduce some of the limitations of a conventional analysis by evaluating (a) the detailed interactions between components of the overall system, and (b) the real potential for improving a system component. The main objective of advanced exergy-based analyses is to provide engineers with additional useful information for better understanding and improving the design and operation of energy-conversion systems. This information cannot be supplied by any other approach. The weaknesses of an advanced exergetic analysis are associated with (a) the subjectivity that is associated with the calculation of avoidable exergy destruction and with the definition of both the ideal and the so-called hybrid processes, and (b) the large number of calculations that need to be conducted to obtain the avoidable endogenous and the avoidable exogenous values.
The Influence of the Roughness Parameters on the EHL Line Contact Using the Free Volume Model
Authors: D’Agostino V. , Petrone V. , Senatore A. 
Published: April 2014

A numerical solution of elastohydrodynamic lubrication (EHL) contact between two rough surface cylinders is presented. In the theoretical approach the free-volume viscosity model is used to describe the piezo-viscous behavior of the lubricant in a Newtonian Elastohydrodynamic line contact [1,2]. Random rough surfaces with Gaussian and exponential statistics have been generated using a method outlined by Garcia and Stoll [3], where an uncorrelated distribution of surface points using a random number generator is convolved with a Gaussian filter to achieve correlation. This convolution is most efficiently performed using the discrete Fast Fourier Transform (FFT) algorithm, which in MATLAB is based on the FFTW library [4]. The maximum pressure and average film thickness are studied at different values of RMS, skewness, kurtosis, autocorrelation function and correlation length. Numerical examples show that skewness and kurtosis have a great effect on the parameters of EHD lubrication. Surface roughness, indeed, tends to reduce the minimum film thickness and it produces pressure fluctuations inside the conjunction which tend to increase the maximum stress. In this way the dynamic stress increases and tends to reduce the fatigue life of the components.
It can be seen that the pressures developed in the fluid film in the case of rough surfaces fluctuate with the same frequency of the surface roughness. These pressure ripples correspond to the asperity peaks. This indicates that surface roughness causes very high local contact pressures which may lead to local thinning of the film. A significant reduction has been also observed in the minimum film thickness due to surface roughness.
Prototyping a New Lightweight Passenger Seat
Authors: Yüce C. , Karpat F. , Yavuz N. , Kaynaklı Ö. , Dolaylar E. , Şendeniz G. 
Published: April 2014

Profitability is the key concern for transport companies. Costs are increased due to the rising fuel prices and technological investments. As well as new legal restrictions on the emission rates have forced the sector different fuel efficient technologies. Reducing weight is one of the most important methods of improving fuel efficiency and cutting CO2 emissions. Accordingly lighter, more fuel efficient, environmentally sustainable and safety vehicles are in the priority list of European authorities. And also the future of hybrid and electric vehicles depends on the lightweighting. The seat structure was chosen as the area for study which presented the best opportunity for weight reduction by the use of new materials. A seat provides comfort and safety of an occupant’s while travelling. In the event of crash, the passenger seat is exposed many different forces. For this reason it should be designed sufficient strength and stiffness. Therefore an optimized seat design should be aesthetically pleasing, ergonomic, light and meet the safety requirements. Seats play an important role in mass of buses and coaches due to number of seats per vehicle. In this project, finite element analysis, together with topology and free-size optimization is used to design a lightweight passenger seat for new generation commercial vehicles.
The seat CAD models were created with CATIA V5 and then imported into HyperMesh for finite element model creation and analysis. Results from the nonlinear analysis provide an accurate prediction of the material yielding and load path distribution on the seat structural frame components. In the end, the verification tests which were determined by ECE are applied the new seat and results were compared with the FEA results.
In this study, the lightweight passenger seat prototypes have developed. High strength steel and fiber-reinforced plastic parts are used. An overall 20% weight reduction is achieved including the structural frame, cushion, armrest, and pillar. And also the new passenger seat provides ECE safety norms.
Insights on Centrifugal Pendulum Vibration Absorber: Part Two — Behaviour of a FWD Powertrain With a CPVA on its Clutch’s Flange
Authors: Simionatto Vinícius G. S. , Miyasato Hugo H. , Dias Júnior Milton 
Published: April 2014

This work is the second and last part of a study whose aim is to present the vibrational aspects of a system with a centrifugal pendulum vibration absorber (i.e. CPVA). The aim of this work, specifically, is to develop a mathematical model of a front engine–front wheel drive powertrain to study gear rattle phenomenon, and to install on its clutch disk’s flange a CPVA in order to understand what are the effects of this device on the dynamics of this system.
Results from the linear analysis show that the eigenfrequencies of the system vary with the engine speed. They oscillate between the eigenvalues of the system without the CPVA and, for regions away from the tuning frequency of the pendulum, which is the second order of rotation of the engine, the behaviour of the system remains the same. However, near the tuning frequency of the pendulum, the behaviour of the system varies very much, and the amplitude of vibration of the gearbox’s inner parts diminishes.
Simulations of the powertrain without and with the nonlinear model of the studied device show that its presence reduces dramatically the vibrations inside the gearbox and its nonlinear character does not influence the effectiveness of this solution.
Numerical Investigation of the Pressure Drop Through Micro-Pillar Arrays for a Wide Range of Aspect Ratios
Authors: Taher Ahmed M. , Jones Benjamin , Adam Ihab G. , Lagae Liesbet 
Published: April 2014

Accurate prediction of the pressure drop through micropillar arrays is essential for many micro total analysis system (μTAS) applications (e.g., liquid chromatography and filtration). Minimizing the pressure drop for such applications is often vital for performing their primary functions efficiently.
In this paper, numerical investigation of pressure drop through square micropillar arrays with different pillar diameter and pitch was conducted. Finite volume discretization method was employed for the numerical simulations using commercial code. Simulation results were validated against experimental data from the literature. A parametric study of geometric variables (pillar diameter, pitch, and height) was performed. Models available from the literature for predicting the permeability of a 2D micropillar array were accessed by comparison to the numerical results. Both dimensional analysis and simulation results were used to develop a new model for square arrangements of micropillar arrays which shows good agreement with numerical simulation results for both 2D and 3D cases. The maximum absolute error between the 3D simulation results and predicted value of the pressure drop has been decreased from 67.3% using a model from the literature to only 1.9% using the proposed model.
Mechanical Property and Degradation in Hot Water of Injection Molded Glass Short Fiber/Wood Powder/Polypropylene Hybrid Composites
Authors: Kong Xujie , Yu Ying , Yang Yuqiu , Li Jungang , Liao Mengyuan , Nomura Manabu 
Published: April 2014

As well known, natural fibers absorb water easily that will affect the mechanical property considerably and there exists a problem of incompatibility which leads the weak interfacial adhesion between the fiber and the resin matrix because of the hygroscopic nature of natural fibers. Therefore, conducting hot water immersion and tensile test is necessary to study the mechanical property and degradation. In this study, glass fiber/wood powder/pp. hybrid composites were prepared by injection molding process at a fixed reinforcement to matrix ratio of 51:49. 3 kinds of hybrid specimens with glass fiber/wood powder ratios of 51:0, 21:30, and 0:51 were fabricated. The hydrothermal aging performance was investigated during the 80°C hot water immersion experiment with a series of immersion time and the effect of hot water immersion on the mechanical properties of composites have been evaluated based on the tensile test.
Results showed that both the strength and modulus of hybrid composite decrease obviously as the immersion time increase, which can be considered that the hydroscopic property of natural fiber would decrease the durability of composite in humidity environment. And the skin-core structure comes from injection molded process contributes to the better hydrothermal aging property of Glass/PP composite.
Exergoeconomic Evaluation of a Solid-Oxide Fuel-Cell-Based Combined Heat and Power Generation System
Authors: Lee Young Duk , Ahn Kook Young , Morosuk T. , Tsatsaronis G. 
Published: April 2014

An exergoeconomic evaluation has been conducted for a 100kW-class SOFC power generation system, in order to evaluate the cost effectiveness of the system. The exergoeconomic analysis is an appropriate combination of an exergy analysis and an economic analysis. Through an exergoeconomic analysis, we obtain the real cost associated with each stream and component in a system. We also can calculate the portion of the cost that is associated with the exergy destruction within each component.
The analyzed system, a 100kW SOFC power generation system, consists of SOFC stack, reformer, catalytic combustor, heat exchangers, pumps, blowers, inverter, and HRSG for heat recovery.
As a first step, mass, energy, and exergy balances were formulated. Then a conventional exergetic analysis (based on the concept of exergy of fuel/exergy of product) was performed. Next, a levelized cost for each component was calculated based on the purchased equipment costs using the Total Revenue Requirement (TRR) method with appropriate economic assumptions. Finally, the cost structure of the SOFC was figured out through an exergoeconomic evaluation. Finally suggestions have been made for reducing the cost associated with the product of the system.
Development and Implementation of an Engineering Course Guided by Involvement in University-Based Professional Development
Authors: Casto Mark , Zeid Ibrahim , Duggan Claire 
Published: April 2014

Amesbury High School is a small suburban district located in the northeastern portion of Massachusetts. Amesbury High School offers a traditional science curriculum (biology, chemistry, and physics) blended with many elective courses. Recently added electives include microbiology, forensics, geology, environmental science, and meteorology to name a few. All of these courses offer students a chance to explore in-depth issues connected to each of these fields with a curriculum designed to address real-life connections, strengthen their problem solving skills, and provide opportunities for application of their knowledge. Based upon review of the Next Generation Science Standards, it became evident a need to offer students a STEM course that was strongly focused on problem-based learning, which bridged math and science content, and offered students a better understanding of the engineering field.
In the spring of 2012, a curriculum was written based upon experiences in Northeastern University’s Research Experience for Teachers Program and the CAPSULE Program which are both funded by NSF. Both of these programs offer rich professional development, is focused on engineering-based learning (EBL), have strong connections to University faculty, and provide teachers the opportunity to develop lessons and units that they can directly apply in their classrooms. The CAPSULE program provided extensive training in developing units based upon the engineering design process (EDP), offered intensive training in SolidWorks® (mechanical design software), and provided each of its participants with continued support through classrooms visits and online discussion forums.
Based upon participation in these programs, available support through University connections, and a deeper understanding of the field of engineering and the EDP, we anticipate the curriculum developed for our students will lead to a deeper understanding of STEM topics and lead to an increase in enrollment in our science and math classes. I also feel that the potential exists to have CAPSTONE projects become a requirement in the newly developed course.
This paper covers the details of the initial offering of the newly-developed course, the changes made for the upcoming school year, and the challenges faced throughout the process of implementation. It also addresses the grant writing successes and failures encountered and how the funding has been used to enhance components of the course. Included in the paper are student reactions and feedback that was considered in revising the course. Lastly, the paper summarizes my involvement in both of these professional development programs and how they are integral to developing leadership skills and confidence within the education profession.
Parametric Analysis and Optimization of Inlet Inflection Angle in Torque Converters
Authors: Liu Cheng , Untaroiu Alexandrina , Wood Houston G. , Yan Qingdong , Wei Wei 
Published: April 2014

Torque converters are widely used in all means of transportations, such as cars, buses, trucks, and the list can go on. Since power is transmitted via fluid, the blade geometry which forms the flow passages is crucial to torque converter performance. The inlet deflection angle is an important blade design parameter with respect to both performance and manufacturability of torque converters. In the conventional design procedure, inlet deflection angle is often given by the designer’s experience or is selected based on experimental data if available. This study presents a method of optimizing the inlet deflection angle for torque converters and provides a series of non-inferior solutions for the decision maker to select from. The advantages of the method proposed consist of improved design quality and significantly shorter design cycle. A combination of computational analysis and global optimization algorithm was used in this study. A torque converter base model was evaluated using computational fluid dynamics for predicting its performance. The proper grid density and turbulence model were selected through correlation to the experimental data available. The following tasks were automated and integrated to form a parameterized design loop: 1) torque converter flow field CAD modeling, 2) meshing, and 3) CFD simulations and results post-processing. Selecting peak efficiency, stall torque ratio and stall pump capacity factor as objective functions, a multi-objective genetic algorithm was included in the design loop to optimize the torque converter performance.
The CFD results proved to be in good agreement with the experimental data over the range of operating conditions considered in this study. The influence of inlet deflection angle on the performance of torque converter was determined through a parametric analysis and a series of Pareto-optimal solutions were determined by the optimization procedure, which proved to improve the performance of the base model torque converter.
Numerical Analysis of Laminar Natural Convection in Rectangular Enclosures of Different Aspect Ratios With and Without Aerosol Nanofluid
Authors: Rahman Mosfequr , Hudson Andrew , Molina Gustavo , Soloiu Valentin 
Published: April 2014

Natural convection heat transfer in rectangular enclosures is important in many real-world engineering applications. Included in these applications are the energy efficient design of buildings, operation and safety of nuclear reactors, solar collector design, passive energy storage, heat transfer across multi-pane windows, thermo-electric refrigeration and heating devices, and the design-for-mitigation of optical distortion in large-scale laser systems, environmental engineering and electronic packaging. A common industrial application of natural convection is free air cooling without the aid of fans and can happen on small scales such as computer chips to large scale process equipment. In addition to temperature gradient convection strength within the enclosure can vary due to the existence of nanoparticles with the base fluid.
The field of nanofluid research has been expanding in recent years. Most of the research performed for the purpose of heat transfer using nanofluids has been conducted on liquid based nanofluids, leaving the aerosol-based nanofluid research lagging. There is also a deficit in the research previously performed to develop a computer model of heat transfer enhancement using nanofluid. The transport of solid particles and liquid droplets in a fluid has long been a subject of great interest. Understanding, measuring, and quantifying the deposition of aerosol on walls is important in various sectors of science and technology. Some examples are the deposition of drugs and harmful substances in the nasal and respiratory tracts in medical science and engineering; deposition of particles and droplets in gas and steam turbines in power plant engineering; the atmospheric dispersal of pollutants and the determination of indoor air quality in environmental science; the transport and sedimentation of various substances in rivers in civil engineering; fouling of process and heat transfer equipments in process industries; and the transport of chemical aerosols in chemical process engineering. In this research work the case of pure air was first solved for 6 different aspect ratios, then the nanofluid was introduced and the resulting heat transfer was observed. The aerosol nanofluid used was composed of air with copper nanoparticles suspended in an enclosure. This procedure was repeated for multiple aspect ratios. This research also develops a functional computer model for heat transfer enhancement using nanofluid.
Integration of Fiber Optic Sensors in Measuring Machines
Authors: Davanlou Ashkan 
Published: April 2014

The production metrology of today is still dominated by tactile probing systems. However some special metrological tasks cannot be fulfilled by this technique, one example is in the high precision manufacturing of surfaces and structures, which become ultra-miniaturized, complex and fragile. The inspection of small boreholes and cavities is also an example with very tight tolerances which demands non-contact miniaturized sensors. Particularly the measurement of the shape of spray holes in modern fuel injection nozzles for diesel engines fits this statement, as its shape represents the key factor for maximal motor efficiency, as well as minimal pollutant emissions. Any deviation from its design shape significantly affects spray breakup and can lead to unequal distribution of flow and pressure changes. These holes can have diameter of 150 microns, with a tendency to even smaller diameters in future systems.
Within this work the integration of a fiber optic sensor for distance measurements in measuring machines, specifically for borehole inspection, is described. The used device is a form-tester (Mahr GmbH, MMQ-400) with 3 degrees of freedom. The motion of the machine axis will be controlled with help of image processing operation which are based on pictures taken from the specimen’s top surface. For this mean a micro camera will be mounted on the form-tester. By applying in-house developed MATLAB codes, the exact position of the boreholes and that of the fiber optic probe is obtained, so that an automated positioning and measurement (e.g. round-out and roundness tests) could be performed. This process enhances both the precision due to an optimized sensor positioning and speed of the measurement rather than manual execution. Different positioning scenarios will be discussed and compared in this paper, to prove the capability of the proposed system as well as its adaptivity.
A Numerical Study for Contained Cold Aisle Data Center Using CRAC and Server Calibrated Fan Curves
Authors: Alkharabsheh Sami A. , Sammakia Bahgat G. , Shrivastava Saurabh , Schmidt Roger 
Published: April 2014

In the present work, we demonstrate the effect of Cold Aisle Containment Systems (CACS) on the airflow and temperature distribution inside a representative data center. Computational Fluid Dynamics (CFD) is used to conduct this analysis. This study includes calibrated fan curves in the Computer Room Air Conditioner (CRAC) and the servers in order to capture the impact of pressure changes on the flow field. The system characteristics curve for the open (uncontained) system and contained system including the leakage effect is established. Since the IT-equipment has a crucial effect on the performance of contained systems, the individual and combined effect of fully enclosing the cold aisle and IT-equipment are investigated. Partially contained systems including doors only and ceilings only configurations are also considered in this study. Steady state and dynamic scenarios are simulated to characterize different containment systems.
It is found that the pressure inside the fully contained system is determined by the IT-equipment as well as the geometrical obstructions of fully containing the cold aisle. Increasing the pressure due to enclosing the cold aisle is reduced by introducing IT-equipment, load banks in this case, which leads to a reduction of the total static pressure and an increase of the flow rate. It is also found that the fully contained system presents the best configurations in achieving low and uniform temperature distribution; however, partially contained systems can be a good solution if a certain cold air provision is maintained during operation. The dynamic analysis shows a significant increase in the safe time at full CRAC failure scenario compared with uncontained system due to utilizing the trapped cold air inside the plenum by the load banks fans.
Re-Examination of NHTSA’s Research Moving Deformable Barrier Front Oblique Impacts With Vehicle to Vehicle Crashes Using FE Models
Authors: Brar Bavneet S. , Tangirala Ravi 
Published: April 2014

The objective of this study is to investigate how the target vehicle’s structural response to NHTSA’s Research Moving Deformable Barrier (RMDB), during oblique impact conditions, compares with actual vehicle to vehicle impacts. It tabulates vehicle kinematics, deformation mode and structural intrusions for both the simulated field accident situations, with a SUV and a small car bullet vehicles, onto a small car target vehicle. These parameters are then compared with those resulting from the RMDB impact simulations. The differences are highlighted and quantified. The effects of the bullet vehicles variation in impact speed were also investigated.
The paper details sensitivity of the RMDB’s Principle Direction of Force by varying the impact overlap percentage. Lastly, further modifications to the RMDB have been suggested to improve its vehicle to vehicle relevance. The FE models used in this research were a full vehicle, restraints and occupant integrated small car model along with a midsized SUV simulation model.