bluuebunny/crossref_metadata_2025_split huggingface dataset:
Feasibility Analysis of Distributed Generation System for Large University Campus
Authors: Allen Amy , Krarti Moncef 
Published: January 2019

Distributed electric generation systems are increasingly considered to offset energy costs and carbon emissions of large building complexes. College campuses, with their physical compactness, and diversity in building loads, present a common application for distributed generation systems. This paper presents the analysis approach and the main results of a feasibility study of a distributed generation system to supply electric and thermal energy for a large university campus, incorporating energy efficiency measures, to reduce carbon emissions at minimal life cycle cost.
The presented study uses a load profile developed based on calibrated detailed simulation energy models for prototypical campus buildings. The calibration analysis is carried out using measured energy consumption data, at the individual building level, and the whole-campus level. Several combinations of distributed generation options are evaluated, using an hourly optimization analysis tool, to meet the entire campus hourly electrical and thermal loads. Proposed efficiency measures and distributed generation options are evaluated using different indicators, including life cycle cost and carbon emissions.
The analysis results indicate that implementing energy efficiency measures to reduce electrical and thermal loads before implementing distributed generation options is the most cost-effective approach to reducing the campus’s energy-related carbon emissions. The results of the study are summarized to guide college campuses and managers of other urban districts as they adapt to a changing energy landscape.
Experimental and Numerical Studies on Dynamic Mechanical Properties of Metal-Polymer Hybrid Materials
Authors: Zhang Yiben , Sun Lingyu , Li Lijun , Wang Taikun , Wang Yantao 
Published: January 2019

Metal-polymer hybrid (MPH) materials can integrate the excellent mechanical properties of metal and complex geometry formability of polymer into a single component, which has become an effective way of reducing the weight of automotive semi-structural components. For example, the hybrid steel/thermoplastic polymer has been applied in automotive front-end modules, bumper cross-beams and B-pillars due to its light weight, excellent strength and stiffness, good corrosion resistance and recycling, high integration and reasonable cost. These components are usually subjected to impact or crash loads and the strain rate effect should be taken into account.
This paper aims to experimentally and numerically study the dynamic behavior of MPH materials at different strain rates and provide an accurate and efficient numerical model for crash simulation of vehicles with MPH components.
Firstly, MPH specimens with high strength steel (HSS) and glass fiber-reinforced thermoplastic polymer (GFRTP) were fabricated by direct injection molding adhesion (DIMA) process. Then, the dynamic mechanical properties of MPH specimens under strain rates from 800 s−1 to 2000 s−1 were investigated by Split Hopkinson Pressure Bar (SHPB) experiments. Finally, a strain rate-dependent numerical model was established in ABAQUS software to simulate the dynamic behavior of MPH specimens and validated by experimental results. Three numerical approaches for modeling the interface between the two discrete material phases were considered and compared to examine the level of interaction between two constitute materials. Cohesive zone modeling technique at the interface which saved modeling and characterization time and showed adequate predictive capability proved to be generally applicable to the evaluation of structural concepts in an early vehicle development stage.
This study provides a foundation for the future engineering application of HSS/GFRP hybrid materials and numerical models for automotive crash simulation.
Wet Gas Compressor Operation and Performance
Authors: Bakken Martin , Bjørge Tor , Bakken Lars E. 
Published: January 2019

The continuous demand for oil and gas forces the petroleum industry to develop new and cost-effective technologies to increase recovery from new fields and enhance extraction from existing fields. Subsea wet gas compression stands out as a promising solution for increasing production capacity, utilizing remote regions and reducing costs.
A prerequisite for successful oil and gas production utilizing subsea wet gas compressors is operability. This includes the system’s ability to cope with operational changes, without having to shut down. One of the fundamental operational changes is the liquid content in the inlet pipe, which may fluctuate considerably at certain time intervals. The current study investigates how changes in liquid content impacts compressor performance.
An experimental test campaign has been performed at the Norwegian University of Science and Technology (NTNU). The test facility is an open loop configuration consisting of a single shrouded centrifugal impeller, a vaneless diffuser and a symmetrical circular volute.
The main objectives were to document how the presence of liquid impacts the compressor characteristics and further, how the operating point moves within the characteristics when solely subjected to an increase of liquid content. The compressor was exposed to liquid contents ranging from gas mass fraction 1.0 to 0.60. The test reveals that the compressor pressure ratio at wet conditions is higher in comparison to dry conditions. Care should be taken when analysing stability and surge margins at variations in fluid liquid content. Further, the compressor behaves in a predictable manner, revealing several linear trends, when subjected to stepwise changes in liquid content from a fixed operating point.
Rattlebacks for Undergraduate Engineers: Modelling Complex Behavior Using Introductory Dynamics and Numerical Methods
Authors: Jones Simon , Kern Kirby 
Published: January 2019

Rattlebacks are semi-ellipsoidal tops that have a preferred direction of spin. If spun in, say, the clockwise direction, the rattleback will exhibit stable rotary motion. If spun in the counter-clockwise direction, the rattleback’s rotary motion will transition to a rattling motion, and then reverse its spin resulting in clockwise rotation. This counter-intuitive dynamic behavior has long been a favored subject of study in graduate-level dynamics classes.
Previous literature on rattleback dynamics offer insight into a myriad of advanced topics, including three-dimensional motion, sliding and rolling friction models, stability regions, nondimensionalization, etc. However, it is the current authors’ view that focusing on these advanced topics clouds the students’ understanding of the fundamental kinetics of the body. The goal of this paper is to demonstrate that accurately simulating rattleback behavior need not be complicated; undergraduate engineering students can accurately model the behavior using concepts from introductory dynamics and numerical methods.
The current paper develops an accurate dynamic model of a rattleback from first principles. All necessary steps are discussed in detail, including computing the mass moment of inertia, choice of reference frame, conservation of momenta equations, and application of kinematic constraints. Basic numerical techniques like Gaussian quadrature, Newton-Raphson root-finding, and Runge-Kutta time-stepping are employed to solve the necessary integrals, nonlinear algebraic equations, and ordinary differential equations.
Since not all undergraduate engineering students are familiar with 3D dynamics, a simpler 2D rocking semi-ellipse example is first introduced to develop the transformation matrix between an inertial reference frame and a body-fixed reference frame. This provides the framework to transition seamlessly into 3D dynamics using roll, pitch, and yaw angles, concepts that are widely understood by engineering students. In fact, when written in vector notation, the governing equations for the rocking ellipse and the spin-biased rattleback are shown to be the same, enforcing the concept that 3D dynamics need not be intimidating.
The purpose of this paper is to guide a typical undergraduate engineering student through a complex dynamic simulation, and to demonstrate that he or she already has the tools necessary to simulate complex dynamic behavior. Conservation of momenta will account for the dynamics, intimidating integrals and differentials can be tackled numerically, and classic time-stepping approaches make light work of nonlinear differential equations.
Method to Reduce Drag Coefficient for Fuel Efficiency in Semi-Truck Trailer and Trailer Stability
Authors: Nair Anu R. , Barez Fred , Thurlow Ernie , Ozen Metin 
Published: January 2019

Heavy commercial vehicles due to their un-streamlined body shapes are aerodynamically inefficient due to higher fuel consumption as compared to passenger vehicles. The rising demand and use of fossil fuel escalate the amount of carbon dioxide emitted to the environment, thus more efficient tractor-trailer design becomes necessary to be developed. Fuel consumption can be reduced by either improving the driveline losses or by reducing the external forces acting on the truck. These external forces include rolling resistance and aerodynamic drag. When driving at most of the fuel is used to overcome the drag force, thus aerodynamic drag proves an area of interest to study to develop an efficient tractor-trailer design. Tractor-trailers are equipped with standard add-on components such as roof defectors, boat tails and side skirts. Modification of these components helps reduce drag coefficient and improve fuel efficiency. The objective of this study is to determine the most effective geometry of trailer add-on devices in semi-truck trailer design to reduce the drag coefficient to improve fuel efficiency and vehicle stability.
The methodology consisted of CFD analysis on Mercedes Benz Actros using ANSYS FLUENT. The simulation was performed on the tractor-trailer at a speed of 30m/s. The analysis was performed with various types of add-on devices such as side skirts, boat tail and vortex generators. From the simulation results, it was observed that addition of tractor-trailer add-on devices proved beneficial over modifying trailer geometry. Combination of add-on devices in the trailer underbody, rear and front sections was more beneficial in reducing drag coefficient as compared to their individual application. Improving fuel efficiency by 17.74%. Stability of the tractor-trailer is improved due to the add-on devices creating a streamlined body and reducing the low-pressure region at the rear end of the trailer.
Effect of Underbody Geometry on the Fuel Efficiency of Gasoline and Electric Vehicles
Authors: Mahadevan Krishnaswamy , Barez Fred , Thurlow Ernie , Abdollahian Davood 
Published: January 2019

Automotive industry in continuously expected to produce more fuel-efficient vehicles. Increasing fuel prices and environmental concerns such as emission of CO2 are two areas in vehicle design improvement. There are multiple factors that affect the fuel economy such as rolling resistance, aerodynamic drag, and weight of the vehicle. As the speed of the vehicle increases, aerodynamic drag force becomes the dominating factor affecting the fuel consumption. This aerodynamic drag is a result of the low-pressure region created at the rear end of the vehicle. This low-pressure region is due to the relative square shape of the vehicle at the rear end which generates vortices.
This project aims to investigate the effects of an underbody in reducing the aerodynamic drag forces and its effects on fuel usage. The underbody in vehicles is one such area in improving the aerodynamics of a vehicle which can have an impact on overall drag force.
Various underbody geometry modifications were carried out on a 3D model of Fiat 500 Electric and Gasoline versions to simulate the effect of underbody geometry on fuel consumption using the CFD simulation tool ANSYS Fluent. It was concluded that the underbody of vehicle influences the overall aerodynamic drag by 20%. Underbody geometry modification helps in reducing the fuel consumption by decreasing the overall aerodynamic drag of the vehicle.
Technology Development and Tool Concepts for High-Temperature Forming of Titanium
Authors: Landgrebe Dirk , Demmler Matthias , Albert Andre , Schieck Frank , Weber Martin 
Published: January 2019

Due to its excellent material properties, titanium is an important structural material for several application fields in the aerospace industry, the chemical industry, medical engineering or marine technologies. Especially its excellent weight-strength ratio, high-temperature strength corrosion resistance and not least its biocompatibility enables a wide field of special applications. These properties can be improved by alloying of other chemical elements.
Despite good availability of resources and moderate world market prices, there is only a limited application range for titanium. Main reasons comprise technological problems in manufacturing processes, particularly related to establish forming technologies such as deep drawing or hydroforming. The forming tool is of significant importance in forming technologies. Beside the function of shape storage the tool must provide the essential forming parameters such as mechanical functions (e.g. blank holder, sealing etc.), but also temperature and tribology. Especially the tribology, also related to forming temperatures, is very critical during titanium forming due to a distinctive tendency of adhesion.
For this reason, a high number of titanium components are manufactured by milling. Parts made by forming of basically thin blank, show only low complexity. More complex components are made by welding of simple shaped parts. Thus, large-series manufacturing of titanium components is limited due to the extensive production cost.
By describing three examples, this paper shows possibilities and challenges in manufacturing of titanium components based on sheet metals. Beside the process parameters, a special focus of the investigations lies on the coating of forming tools. Example one is cold forming of thin titanium blanks to speaker cones. The second example demonstrates superplastic forming of a medical application, and finally the third example consists of hot gas forming of a titanium exhaust manifold.
The investigations have shown that based on optimized technological parameters in combination with new tool coatings, the manufacturing of complex sheet metal based titanium applications is applicable for large-series production.
A Reduced-Order Model for Predicting the Performance of a Liquid-Ring Vacuum Pump
Authors: Pardeshi Irsha , Pandey Ashutosh , Shih Tom I-P. 
Published: January 2019

Vacuum and low pressures are needed in many applications, and the liquid-ring vacuum pump, which does not have any solid-solid contacts between moving and stationary parts, is widely used because of its low operational cost and long service life. Though progress has been made in advancing this pump, industry still has aggressive goals on improving its efficiency and performance.
In this study, a reduced-order model was developed to predict the ability of liquid-ring pumps to ingest air and thereby create lower pressure as a function of pump design and operating parameters. The model developed is semi-empirical — constructed by first analyzing available experimental data to extract features and trends and then encapsulating them into a model through appropriate dimensionless parameters. This model by being in closed form shows the functional relationship between the pump’s design and operating parameters and its ability to ingest air and create a vacuum. To make predictions, this model only requires the following inputs: suction pressure, impeller’s rotational speed, and a few dimensions of the pump.
The model developed was assessed by using it to predict the ability of the pump to ingest air for a wide range of suction pressures (cavitation pressure to 760 torr), rotor speeds (up to 1,750 rpm), and dimensions of the pump (radius and span of the impeller blade, hub radius) and then comparing predictions with experimental data not used in the creation of the model. The model developed was found to be accurate within 11% of the experimental data.
A Systems Engineering Approach to Incorporating the Internet of Things to Reliability-Risk Modeling for Ranking Conceptual Designs
Authors: D’Angelo Anthony , Chong Edwin K. P. 
Published: January 2019

This paper establishes the baseline for incorporating the Internet of Things (IoT) into the Reliability-Risk model. The authors developed the original Reliability-Risk model as a “trade-off” tool for ranking conceptual designs as a function of reliability. We summarize the original Reliability-Risk model and algorithm and discuss the process of updating the standard Integration Definition Function Modeling (IDEF0) technique with the IoT. Inserting the updated IDEF0 into the Reliability-Risk modeling framework creates a dynamic closed-loop system. We identified a concept for using a probabilistic workflow to automate the new closed-loop system and discuss a Reliability-Risk sensitivity approach.
The Reliability-Risk model ranked five conceptual packaging designs against 17 criteria for incorporation into the supply chain. The authors use a Multi-Criteria-Decision System (MCDS) to establish the rankings. The paper re-visits the original example to include data (the IoT) such as shock, temperature, and humidity obtained from various nodes in the logistics cycle. After the sensor data are incorporated, updated systems specification and reliability models resulted in a new ranking. We will discuss the results of the rankings.
Current research in developing the Digital Twin and Digital Thread are lacking in the area of logistics modeling. The incorporation of Discrete Event Simulation models to simulate transportation, handling, and storage shows promise to address these shortcomings. Therefore, we will briefly discuss our approach on incorporating Discrete Event Simulation modeling into the Reliability-Risk-IoT model to create a “logistics twin.”
Application of Systems Engineering to Machine Design for Technology Students
Authors: D’Angelo Anthony , Chong Edwin K. P. 
Published: January 2019

This paper discusses the results of a literature search on implementing novel approaches to teaching engineering design as well as the need for teaching Systems Engineering (SE) at an undergraduate level. In addition, the paper presents the results and lessons learned by assigning a capstone project requiring students to develop a conveyor system using the 8-phase SE process and a project based collaborative design methodology.
The instructor teaches the fundamentals of systems engineering, the concept of synthesis, and the basics of trade-off studies. Students learn how to use functional modeling and the proper use of a functional flow block diagram to transform design requirements into failure modes.
Students perform traditional failure mode calculations, using a strength-resistance approach, on machine components such as shafts, bearings, gears, belts, chains, keyways, splines, clutches, springs, brakes, and bolts for the conveyor system’s transmission.
The instructor assigns a conveyor system and its systems requirements and students must demonstrate their understanding of the SE process as well as being able to perform design calculations on various machine components.
The students demonstrate their understanding of SE and failure modes by taking part in design reviews throughout the semester and a final engineering report.
Exploring Training Methodologies Towards the Improvement of Elderly Balance
Authors: Thompson Lara A. , Brusamolin Joao Augusto Renno , Guise Jelani , Badache Mehdi , Estrada Sandy Collado , Behera Lonika , Savadkoohi Marzieh , Coombs Tyra , Guerrero Pablo Sanchez , Shetty Devdas 
Published: January 2019

The purpose of this study was to investigate the effects of utilizing sensory (i.e., vision and touch), as well as static and dynamic base of support training on the balance of senior participants aged 60–80 years old. For each participant, there were several weeks of training, two sessions per week and assessments every two weeks. Training included walking and standing exercises on a hard surface, compliant and stiffer foam walking and standing balance training, and navigating obstacles. Within each session, to modify vision, all training included eyes-open and closed. Further, there were increases in training difficulty as the sessions progressed.
It was observed that training over several weeks resulted in increases in stability, as observed by the decreases in Balance Error Scoring System (BESS) assessment results. However, increases in balance confidence, as observed by the Activities-Specific Balance Confidence (ABC) scale were less certain in this healthy elderly (or senior) population. It is an interesting and positive finding that, in doing relatively simple, but targeted exercises and training, senior individuals can have moderate improvements in their balance and, perhaps ultimately, reduce their fall-risk.
An Acoustic Analogy to Evaluate the Total Acoustic Power of a Cooling Fan Using Mesh Morpher Optimizer
Authors: Kheirallah Mike A. , Hamieh Abdallah , Jawad Badih , Liu Liping 
Published: January 2019

The pressure fluctuation over the fan blades can generate unpleasant noises that affect the fan performance. Therefore, the noise control is considered as a significant factor in the design process. The purpose of this study is to estimate the total acoustic power of the surface on a cooling fan as a key function to improve design parameters.
The design process of a cooling fan to achieve low acoustic power can be lengthy and expensive through prototyping and experiments. The Mesh Morpher Optimizer (MMO) in ANSYS Fluent in coupling with the Powell’s model was applied to estimate the acoustic power over a cooling fan surface at a low speed. The Powell’s model in ANSYS was proved successfully in reducing the total acoustic power on the surface of the cooling fan which is shown by the numerical results. Comparison of the base model and Powell’s model, the Acoustic Power Level was reduced from 23.68 to 21.69 dB. The Surface Acoustic Power Level dropped from 62.24 to 61.26 dB. Likewise, the Surface Acoustic Power decreased from 9.67e−5 to 5.24e−5 W/m2. Also, the contour visualization results verified the success of the Powell’s model in combination of the Mesh Morpher Optimizer (MMO) to evaluate the total acoustic power and propose a new model that will assist in the design process in minimizing the manufacturing process of a new design model.