bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite Element Method for Fluid Flow in 3D Domains Containing Moving Interfaces
Authors: Mazumder A. K. M. Monayem H. 
Published: January 2020

Abstract
This study presented a three-dimensional (3D) finite element method (FEM) for the numerical analysis of fluid flow in domains containing moving interfaces. This method falls into the general category of Arbitrary Lagrangian Eulerian (ALE) method; based on a fixed mesh that is locally adapted at the moving interfaces and reverts to its original shape once the moving interfaces go over the elements. The 3D domain occupied by the fluid at any time in the simulation is used as the reference domain and is discretized using a mesh of hexahedral tri-linear isoparametric finite elements. The moving interfaces are defined by sets of marker points so that the global mesh is independent of interface movement and eliminates the possibility of mesh entanglement. The mesh never becomes unsuitable due to its continuous deformation, thus eliminating the need for repeated re-meshing and interpolation. A validation is presented via a problem with an analytical solution for the 3D flow between two planes separating at a prescribed speed that shows second order accuracy. The model’s capabilities are illustrated through application to laminar incompressible flows in different geometrical settings that show the flexibility of the technique.
Analytical and Numerical Modelling of Sheet Plate Cold Expanded Hole Subjected to Reverse Yielding
Authors: Bouzid Abdel-Hakim , Touahri Hacène 
Published: January 2020

Abstract
Predicting and mitigating the effect of expansion induced by cold working on damage fatigue accumulation and life assessment of aluminum alloy is a common process in the aeronautics industry, especially to extend the fatigue lifetime of their structures. This process aims at generating residual stresses and increases thereby the strength of hollow parts including aluminum alloy plate holes that are employed in manufacturing the airplane fuselage.
An analytical model to predict the residual stresses induced during the expansion process due to the cold strain hardening is developed. The proposed model is based on an elasto-plastic behavior, with a power law material behaviour and relies on the theory of autofrettaged thick wall cylinders in plane strain state to which reverse yielding is incorporated. The application of Hencky theory of plastic deformation is used in the analytical calculations of the stresses and strains. Finite-element numerical simulation is used to validate the developed analytical model by comparison of the radial, Hoop, longitudinal and equivalent stresses for both the loading and unloading phases. The obtained results show clearly that the level of residual stresses depends mainly on the interference and strain hardening while reverse yielding reduce the stresses near the hole.
Nonlinear Design of a Passive Vibration Isolator: Influence of Multi-Axial Stiffness
Authors: Kaul Sudhir 
Published: January 2020

Abstract
Passive vibration isolators are widely used in multiple engineering applications to reduce resonance peaks or to mitigate transmissibility in the presence of internal or external sources of dynamic excitation. The design of a linear passive isolator involves multiple trade-offs. In the literature, different design configurations with nonlinearities have been investigated to limit some of these trade-offs. These include designs with quasi-zero stiffness (QZS) or high-static-low-dynamic stiffness (HSLDS) characteristics. This study investigates three viscoelastic models that incorporate stiffness nonlinearity along the non-isolating axes in order to exhibit more control over the dynamic response of the isolated system and possibly mitigate some of the design trade-offs. The dynamic response of these three models is compared to an existing HSLDS model in the literature. The three models investigated in this study are as follows: Kelvin-Voigt (or Voigt), Zener, and Generalized Maxwell (or Maxwell Ladder). These three models have been commonly used in the literature for vibration analysis of passive isolators. Two methods have been used for analysis, namely the Harmonic Balance Method (HBM) and explicit numerical integration. Test results from a previous study have been used for model characterization of all the models. It is observed that the modified Kelvin-Voigt model is analogous to the HSLDS model from the literature. For the isolator parameters used in this study, it is observed that the Kelvin-Voigt model with stiffness nonlinearity is able to exhibit characteristics similar to the HSLDS design, this includes the jump phenomenon as well as the hardening behavior. In general, all three models demonstrate that stiffness nonlinearity results in a reduction in peak transmissibility as well as an enhancement of the isolation bandwidth. The findings of this study could be useful in the design of passive isolation systems for products with significantly different multi-axial requirements with various design constraints.
Near Critical Carbon Dioxide Characteristics of Heat Transfer Processes in Microchannels
Authors: Parahovnik Anatoly , Asadzadeh Mostafa , Peles Yoav 
Published: January 2020

Abstract
Convective heat transfer of CO2 flows near the critical condition in a 300 μm hydraulic diameter microchannel was visualized and measured. Flow patterns of the gas, liquid, and supercritical phases are presented and discussed. An experimental rig and a microfluidic device were designed and constructed to enable precise control and measurements of temperature, pressure, and mass flux. Heaters and resistive temperature detectors (RTDs) were formed on the microchannel wall to provide heating power and to measure local surface temperature. Flow patterns for the near-critical condition of CO2 were visualized, and local heat transfer coefficient (HTC) of 4.5, 6.1, and 150 kW/m2K were measured, for gas supercritical and liquid cases, respectively. It was observed that there is a distinct difference in flow and heat transfer patterns of different phases near the critical point, which leads to the deviation of the HTC. Also, CO2 presents high HTC coefficients for supercritical and boiling conditions that make it a viable option as thermal fluid for different micro scale applications.
Ultrasonic Casting of Off-Eutectic Tin Bismuth Solder Alloy for Mechanical Property Testing
Authors: Smith Laura , Jennings Jeff 
Published: January 2020

Abstract
Knowledge of solder mechanical properties is essential when designing electronic assemblies for use in harsh environments like those that exist in automotive or aerospace applications. However, information on solder mechanical properties is limited because fabricating material samples in a form factor used for typical mechanical testing is difficult. Conventional casting processes are prone to void formation and dross inclusion which can degrade the quality of test results acquired and often produce high degrees of variability.
The current work describes in detail a novel casting process which seeks to address these solder sample fabrication issues. The non-conventional process applies ultrasonic excitation to eliminate voiding by breaking up dross inclusions and other voids, so none can form within the melt upon solidification. Cast ingots are machined then undergo non-destructive screening to ensure material consistency within the regions critical to producing good test results prior to being subjected to destructive mechanical testing. This ultrasonic casting process is applied to the testing of an off-eutectic Tin-Bismuth solder alloy and its ambient tensile and compressive stress versus strain properties are evaluated. The improvement in result repeatability for the various tested properties due to the ultrasonic casting are assessed and sample size considerations discussed.
Borehole Temperature Modelling in High Temperature Drilling Environment Based on Heat Transfer Laws
Authors: Chodankar Abhijeet D. , Lin Cheng-Xian 
Published: January 2020

Abstract
High temperature drilling environment has a drastic effect on drilling fluids, wellbore stability, and drilling system components. It has been observed that drilling fluids displace conventional halide based fluids in High Pressure and High Temperature (HPHT) wells leading to corrosion and environmental hazards, while wellbore strengthens further as a result of an increase in fracture initiation pressure in high temperature environment. However, it seriously damages the downhole tools like sensors, elastomer dynamic seals, lithium batteries, electronic component and boards leading to increases in cost and non-productive time. The main objective of this paper is to present an analytical borehole temperature model based on classical heat transfer laws in a high temperature drilling environment. The borehole is modelled using two approaches: composite wall and concentric cylinders. The composite wall and concentric cylinder approaches consist layers of geological formations, drilling fluids outside the drill string, drill string, and drilling fluid inside the drill string. Temperature, heat transfer coefficient, and heat transfer variations along the borehole layers are determined using the derived analytical solutions and tested for different drilling fluid types, air drilling environment, and different drill string materials. The results of composite wall and concentric cylinder models are obtained by using the input field temperatures data in the geological formation and inner annulus of drill pipe to determine the borehole temperature profile in HPHT wells. Therefore, a thorough borehole heat transfer analysis will help in wellbore stability, drilling fluid selection, corrosion control, and optimal placement and material selection of drilling components in HPHT drilling environments.
Using a Heat Pump Experiment With Automated Data Acquisition to Augment Hands-On Learning
Authors: Anderson Kevin R. 
Published: January 2020

Abstract
This paper presents the results of using laboratory facilities in conjunction with computer aided data acquisition in order to enhance the teaching and learning experiences of the air conditioning and measurements/instrumentation courses in an engineering program. The paper discusses the use of educational technology in the form of a laboratory experiment developed for support of Science Technology Engineering and Math (STEM) education in an engineering curriculum. The experimental apparatus discussed in the paper is a heat pump demonstration unit with LabView data collection and visualization software. The use of modern technology in the classroom is illustrated in this paper by using a heat pump demonstration unit to illustrate the physical principles of air conditioning and heating. Data collection and acquisition/instrumentation, data reduction curriculum is addressed by using an automated data collection system to gather data for the heating and cooling processes. The main objectives of the study were to i) expose STEM students to LabView based data collection, ii) enhance the curriculum of air conditioning and measurements science by using hands-on facilities, iii) develop technical report writing and data reduction skill sets. The experiment is conducted in small teams of 3 to 4 students in order to make the experiential learning a more intimate process. The heat pump hardware is used to illustrate real world working system. The experiment is composed of a compressor, an evaporator, a condenser and throttling valve. The unit allows for operation as both a heat pump and a refrigeration unit. Thus illustrating the concept of Coefficient of Performance (COP) and Energy Efficiency Ratio (ERR) for both the heat pump and the refrigeration mode are enabled. The unit works on R134A and water as the working fluids. The unit is instrumented with a control thermostat allowing the set-point of the device to be changed. Thermocouples, pressure transducers and flow rate meters are used to collect live data which is fed to the LabView based data-acquisition platform. By using such equipment in the teaching of the Air Conditioning curriculum, it allows the students
Mechanical Characterization of Valve Compression Packing at High Temperature
Authors: Legault Xavier , Bouzid Abdel-Hakim , Aweimer Ali Salah Omar 
Published: January 2020

Abstract
Packed stuffing boxes are sealing devices used in valves, compressors and pumps. The compression packing is the most critical element of this assembly. Packing rings are compressed axially to produce lateral contact pressures large enough to confine the processed fluid within the pressurized valve and avoids leakage to the outer boundary. Although popular, this old method of sealing has seen very limited analytical and numerical development. There is no standard design procedure for engineers to follow, and the existing standard test procedures are limited to qualification and quality control tests such as API622, 624, ISO-15848 1 and 2. As a result, structural integrity and leak tightness are rarely verified, and consequently 60 % of pressurized equipment requiring fugitive emissions compliance are valves that use this type of sealing device.
The mechanical properties of compression packing materials are the main factors affecting fluid tightness at room and high temperatures and yet there is little or no data available either in manufacturer’s catalogues or in the literature. Packed stuffing box research is scant and focuses mostly on the distribution of the contact pressure between the stem and packing at room temperature without considering packing mechanical properties such as rigidity, thermal expansion, creep and aging. It is proposed, in this project, to measure the mechanical properties such as pressure transmission ratio, short-term creep deformation and thermal expansion coefficient of two packing materials at high temperature. This initiative will serve as a basis to launch a North American testing program to develop ASTM-like testing procedures for compression packing at high temperature.
Assortment of Hydroforming Fluid for Extreme Pressure and Anti Wear Properties
Authors: Rudraksha S. P. , Gawande S. H. 
Published: January 2020

Abstract
Lubricants play vital role in tube hydroforming (THF) process to reduce friction between tool and die wall interface which helps to enhance the quality of finished product. The process parameters and quality of components is influence by the friction between the tube and inner surface of the die. Excellent lubricant reduces the problem of wrinkling, buckling and premature failure of the component. Extreme pressure, Anti-wear, and frictional properties of fluid influence the performance of tube hydroforming process. In this paper EP (extreme pressure), anti-wear and friction properties of hydroforming lubricating oils as Enklo68, Enklo46, Enklo32 and Enklo100 are investigated. Test method as per ASTM standards is used for the measurement of EP and wear preventive properties of hydroforming fluids by using Ball Tester TR – 30L under atmospheric pressure of lubricating oil at 392 N load and 75°C temperature with constant speed of 1770 rpm. From experimental investigations it is observed that as Enklo68 is more suitable hydroforming fluid as compared to Enklo46, Enklo32 and Enklo100 as its observed coefficient of friction (i.e. 0.10581) is very less.
Numerical and Experimental Analysis of Twisted Tape Insert in Circular Tube
Authors: Chandratre V. S. , Keste A. A. , Sane N. K. 
Published: January 2020

Abstract
Energy is a major area of concern for many industrial and engineering applications. For the development of energy efficient heat exchangers, heat transfer enhancement by passive inserts have growing research potential. The present study gives the numerical and experimental analysis of twisted tape insert in a circular tube for the range of Reynolds number between 5000 to 15000 with heat flux variation from 500W/m2 to 1.5 kW/m2 with air as working medium. A circular tube of 52.5 mm internal diameter, 60 mm outer diameter and 1000 mm length is used as test section with uniform heat flux. Twisted tape used is of Aluminum material having a pitch of 100 mm. Outside surface temperatures are measured at different locations on test section. Two ‘T’ type thermocouples are used to measure air temperature at inlet and outlet of test section. From numerical and experimental analysis it is observed that the Nusselt number increases for twisted tape as compared to smooth bare tube by 2.2–3.1 times. Again the Nusselt numbers obtained for smooth tube is compared with Dittus-Boelter and Gnielinski correlation and it is observed that the error is within acceptable limit of 10% variation. An error of 10% variation is observed in friction factor obtained by experimental analysis and Blasius and Petukov correlations.
Explicit Evaluation of Design Readiness for Student Refinement of Conceptual Design
Authors: Iino Kenji , Nakao Masayuki 
Published: January 2020

Abstract
Students at three graduate schools of mechanical engineering and adult groups in Japan have been taking conceptual design courses the authors teach. Among the three graduate schools, the 24 hour course, at the University of Tokyo, spread over 13 classes during 4 months, takes the students all the way from identifying their design goals, generating ideas, refining their designs, to building prototypes. The adult course students also spend long hours of building prototypes. Despite strong encouragement by the instructors for detail design, the students often leave their design concepts at rough stages without refining their ideas to the detail level needed for prototype building. Building a prototype from a design concept that is not fully expanded often results in efforts that lead to failure and retrial. Such back and forth between concepts and physical trial is unavoidable in design, however, if possible they better be kept at the minimum. The instructors, in their efforts to better motivate students to refine the designs, developed a metric “Level of Readiness (LOR) index” for evaluating how refined a design is. Students are better motivated to reach higher scores and this index that evaluate the quality of their designs, in terms of how detail they are, in numbers serves as a better incentive for the students than words from the instructors.
A Numerical Investigation of the Effects of Structural Properties on the Performance of a Two-Section Porous Medium Burner
Authors: Rahimi Borujerdi P. , Akbari Hadi 
Published: January 2020

Abstract
Porous media combustion is a feasible approach to tackle challenges encountered in free flame burners by offering advantages such as lower pollutant emissions, higher flammability limits and better flame stabilization. This study computationally investigated the premixed combustion of a methane/air mixture in a porous medium burner. The porous medium consisted of two sections: The upstream one was called the preheating section; The downstream one was called the combustion section. For methane oxidation, GRI 3 mechanism including 53 species and 325 reactions was used. After a successful validation against the experiments, a baseline study was conducted. Furthermore, a parametric study was performed to illustrate the effects of the structural properties of the combustion section on the burner performance. Increasing the pore density decreased the temperature difference between the gas and the solid phases. Consequently, a burner with higher pore density in the combustion section exhibited less emissions. When the porosity of the combustion section increased, the gas phase temperature also increased but the solid phase temperature remained virtually unchanged for the porosity values studied. As a result, higher pollutant emissions were observed at the burner outlet. Finally, it was noticed that when the combustion section was elongated, both phases gained higher temperatures and while CO emission decreased, NO emission increased.
Automotive Laminated Side Glazing Rollover Performance When Subjected to Roadway Abrasion and Occupant Loading
Authors: Phillips Donald R. , Batzer Stephen A. 
Published: January 2020

Abstract
Destructive testing of commercial automotive movable laminated side glass was conducted to document the occupant retention characteristics of this glazing system in quarter-roll crashes with a prolonged slide distance. That is, in some overturns a vehicle will slide to a halt on its side with a window adjacent both to an occupant’s position and to the moving roadway. It is known by field experience that this situation can result in injurious ejection of the occupant through the adjacent window if the window is constructed of tempered glass and the window has fractured. When tempered glass fractures, the window disintegrates and fully opens the portal. With the laminated side glazing that is used on some passenger vehicles, fracture of the inboard and outboard glass plies will not necessarily cause the “sandwiched” PVB interlayer to be compromised. This PVB interlayer allows the glass plies to remain in place and resist the sliding interaction. This diminishes the ejection hazard that is associated with tempered side glass. The three drag tests described within this technical paper used a single model of sport utility vehicle driver’s position door and factory installed laminated side door glass. The testing replicated the interaction of the exterior surface of the laminated glass against the moving roadway while the glazing was pre-fractured and the interior glass ply was subjected to significant simulated occupant loading. These conditions ensured contact of the exterior glass ply against the moving abrasive roadway. The detached and slightly modified driver’s door was pulled at near highway speed over a substantial distance against abrasive asphalt, simulating a rollover accident with the side of the vehicle sliding to halt. The results of these tests show that the exterior surface of the glazing, primarily consisting of the hard ceramic SiO2, is sufficiently wear resistant and durable to wear but not rupture or pull out of the peripheral channel. This testing shows that laminated glass is the superior glazing material for this accident mode from an occupant containment perspective.