bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Natural Evolution Based Numerical Optimisation Framework to Develop and Enhance Airfoil-Slat Arrangement
Authors: Kumar Sushrut , Gupta Priyam , Singh Raj Kumar 
Published: January 2020

Abstract
Leading Edge Slats are popularly being put into practice due to their capability to provide a significant increase in the lift generated by the wing airfoil and decrease in the stall. Consequently, their optimum design is critical for increased fuel efficiency and minimized environmental impact. This paper attempts to develop and optimize the Leading-Edge Slat geometry and its orientation with respect to airfoil using Genetic Algorithm. The class of Genetic Algorithm implemented was Invasive Weed Optimization as it showed significant potential in converging design to an optimal solution. For the study, Clark Y was taken as test airfoil. Slats being aerodynamic devices require smooth contoured surfaces without any sharp deformities and accordingly Bézier airfoil parameterization method was used. The design process was initiated by producing an initial population of various profiles (chromosomes). These chromosomes are composed of genes which define and control the shape and orientation of the slat. Control points, Airfoil-Slat offset and relative chord angle were taken as genes for the framework and different profiles were acquired by randomly modifying the genes within a decided design space. To compare individual chromosomes and to evaluate their feasibility, the fitness function was determined using Computational Fluid Dynamics simulations conducted on OpenFOAM. The lift force at a constant angle of attack (AOA) was taken as fitness value. It was assigned to each chromosome and the process was then repeated in a loop for different profiles and the fittest wing slat arrangement was obtained which had an increase in CL by 78% and the stall angle improved to 22°. The framework was found capable of optimizing multi-element airfoil arrangements.
The Interaction Problem Between a Crack and a Wedge Disclination Dipole With Irwin Plastic Zone Correction
Authors: Cao Meigen , Fan Mu , Min Hequn 
Published: January 2020

Abstract
In this work, the multiple defects interaction problem is studied. A crack located near an inclusion is influenced by a wedge disclination dipole. Stress field induced by the disclination affects the crack tip field and yield behavior of the crack. With varying the wedge disclination dipole properties, including strength, position to the crack tip, arm length, etc., the plastic zone size (PZS), the crack tip opening displacement (CTOD) and the stress intensity factor (SIF) are estimated with the generalized Irwin model. Numerical results showed that the wedge disclination dipole arm length and strength can significantly increase or decrease the values of the CTOD and PZS, depending the disclination dipole positions. The maximum values of the CTOD and the PZS were explored with the change of disclination position.
Wettability Gradients on Graphene to Drive Bubble Motion
Authors: Yu Hongyang , Zhao Yu , Sha Jingjie , Chen Yunfei 
Published: January 2020

Abstract
The molecular dynamics (MD) method is employed to simulate thermal bubble nucleation processes confined in graphene nanochannels. It is found that nucleation sites depend strongly on the different solid-liquid interfacial properties in various systems. In this work, the thermal bubble nucleates on the graphene surface, on which the interaction between liquid molecules and channel wall is weak relatively. It is demonstrated that the hydrophobic surface would make thermal bubble to initiate easier. A conceptual design about surface wettability gradient was proposed, which can break the equilibrium state of a bubble and induce its unidirectional movement on the surface. Moreover, MD simulation showed that through a continuous gradient of surface wettability, the direction of movement is under control. These findings provide us with a method in device design for applications of self-controlling motion of bubble down to nanoscale and other wettability-enabled actuators.
Study on Fracture Mechanism and Fatigue Life Prediction for Cutting In-Situ TiB2/7050Al MMCs
Authors: Xiong Yi-feng , Wang Wen-hu , Lin Kun-yang , Liu Xiao-fen , Jiang Rui-song , Deng Chu-quan 
Published: January 2020

Abstract
For machined parts, the surface roughness and profile would have a significant impact on the fatigue life and fracture mechanism. At present, a lot of research have been carried out on the cutting mechanism, modeling and machining performance of particle reinforced Al-based metal matrix composites. However, the study of fatigue life and fracture mechanism of machined parts after cutting particle reinforced Al-based metal matrix composites is rarely reported. In this paper, the fatigue life and fatigue fracture morphology of in-situ TiB2/7050Al MMCs were studied by high cycle fatigue test under different loading stresses. It was found that the surface roughness influenced the fatigue life greatly. With surface roughness decreasing, the fatigue life of machined parts increased exponentially. The fracture mechanism of cutting in-situ TiB2/7050Al MMCs was found to be brittle fracture due to the existence of fine particles. Besides, a fatigue life prediction model was established based on the machined surface roughness. With validation, the relative errors between prediction model and experiment were smaller than 11% indicating that the proposed fatigue life prediction model of machined in-situ TiB2/7050Al MMCs parts was of good reliability and accuracy.
Delamination Detection in Composite Plates Using Linear and Nonlinear Ultrasonic Guided Waves
Authors: Shen Yanfeng , Cen Mingjing 
Published: January 2020

Abstract
This paper presents a delamination detection strategy for composite plates using linear and nonlinear ultrasonic guided waves via the wave field imaging and signal processing based on Scanning Laser Doppler Vibrometry (SLDV). The anisotropic elastodynamics in composite plates is first studied. Two numerical methods are deployed to analyze the wave mechanics within the composite plates. The Semi-analytical Finite Element (SAFE) method is utilized to obtain the dispersion curves and mode shapes for a carbon fiber composite plate by bonding two quasi-isotropic carbon fiber composite panels together. The Local Interaction Simulation Approach has been employed to investigate the wave propagation and interaction with the delamination. Contact Acoustic Nonlinearity (CAN) between the delamination interfaces during wave damage interaction is presented as a potential mechanism for delamination detection. After developing an in-depth understanding of the wave propagation and wave damage interaction mechanism, active sensing experiments are conducted using the Piezoelectric Wafer Active Sensors (PWAS) and the Scanning Laser Doppler Vibrometry (SLDV). Two delamination imaging methodologies are presented. The first one utilizes the total wave energy to detect the delamination, taking advantage of the trapped modes within the delaminated area. The second one adopts the nonlinear second harmonic imaging algorithm, highlighting the nonlinear interaction traces at the delamination region. The damage detection images are finally compared and fused to provide detailed diagnostic information of the delamination. The damage imaging technique presented in this paper possesses great potential in material evaluation and characterization applications. This paper finishes with summary, concluding remarks, and suggestions for future work.
Comparative Energy and Exergy Analysis of Proposed Gas Turbine Cycle With Simple Gas Turbine Cycle at Same Operational Cost
Authors: Khan M. N. , Alarifi Ibrahim M. , Tlili I. 
Published: January 2020

Abstract
Environmentally friendly and effective power systems have been receiving increased investigation due to the aim of addressing global warming, energy expansion, and economic growth. Gas turbine cycles are perceived as a useful technology that has advanced power capacity. In this research, a gas turbine cycle has been proposed and developed from a simple and regenerative gas turbine cycle to enhance performance and reduce Specific fuel consumption. The impact of specific factors regarding the proposed gas turbine cycle on thermal efficiency, net output, specific fuel consumption, and exergy destruction, have been inspected. The assessments of the pertinent parameters were performed based on conventional thermodynamic energy and exergy analysis. The results obtained indicate that the peak temperature of the Proposed Gas Turbine Cycle increased considerably without affecting fuel consumption. The results show that at Pressure Ratio (rp = 6) the performance of the Proposed Gas Turbine Cycle is much better than Single Gas Turbine Cycle but the total exergy destruction of Proposed Gas Turbine Cycle higher than the SGTC.
Numerically Constructed Energy Consumption Mapping for the Orthogonal Machining of Ti6Al4V
Authors: Nouzil Ibrahim , Pervaiz Salman , Kannan Sathish 
Published: January 2020

Abstract
Energy efficiency is an important aspect of all industrial processes. Sustainability in manufacturing sector can be improved by reducing and optimizing the energy requirements of the machine tool during the machining process. Growing energy demand and shortages in conventional energy sources have prompted research into energy conservation and sustainable development. Machining of difficult-to-cut materials such as titanium-based alloys involve high consumption of energy and hence it is compulsory to study the optimal combinations of process parameters that yield the best result with highest efficiency in terms of energy. This paper aims to develop a finite element (FE) assisted virtual energy consumption map for the machining of Ti6Al4V in orthogonal turning operation. The cutting power for the machining process is simulated in AdvantEdge specially designed machining software for specific cutting parameters. The map developed is universally applicable and independent of the machine tool as only cutting power is used. The visual energy map can be utilized at the shop floor level, as it is easily understandable to the operator. The information enabled through the map can help the operator select the optimal combination of process parameters for the machining process and maximize the energy based efficiency of the cutting process.
Parametric Study of Split Flow Cylindrical Packed Bed Reactor for High-Temperature Thermochemical Energy Storage Using Cobalt Oxide Redox Reaction
Authors: Vahedi Nasser , Oztekin Alparslan 
Published: January 2020

Abstract
Thermal energy storage has become an integral part of Concentrated Solar Power (CSP) plants to guarantee continuous supply of power demand. For cost-effective solar power generation, the size and operating temperatures of CSP plants should be increased. Thermochemical energy storage (TCES) is the only available solution to meet energy density and high-temperature requirements. Air is mostly used as Heat Transfer Fluid (HTF) for high-temperature CSP plants. For the air-based system, metal redox reactions are good candidates as storage reactant. Application of metal oxide gas-solid redox reaction in storage systems requires an efficient reactor design. Cost-effectiveness and simplicity have made packed bed reactors a viable candidate for high-temperature applications. The high-pressure drop along the bed is the main drawback of such reactors preventing them from widespread applications. Split flow design modification could aid in reducing pressure drop while providing more flexibility in reactor performance control. A cylindrical split-flow packed bed reactor with an annulus for HTF flow is considered as a modified reactor design. The transient two-dimensional axisymmetric numerical model is developed for solving mass, momentum, and energy equations for both gas and solid phases using suitable reaction kinetics for the cobalt oxide redox reaction. A parametric study is performed on cylindrical-shaped split-flow reactor design as a basis for future optimization for complete storage cycle. The effect of split flow ratio and side-channel width on reactor performance are considered. It is shown that both parameters could be used effectively to design and optimize the reactor.
On an Independent Period-1 Motion in a Flexible Rotor System
Authors: Xu Yeyin , Luo Albert C. J. 
Published: January 2020

Abstract
This paper investigates stable and unstable period-1 motions in a rotor system through the discrete mapping method. The discrete mapping of a nonlinear rotor system is for stable and unstable period-1 motions. The stability and bifurcation of periodic motions are determined. Numerical simulations of periodic motions are completed and phase trajectories, displacement orbits and velocity plane are illustrated. The period-1 motion near the internal resonance is determined with large vibration in the nonlinear rotor system.
Temperature Regulated Sleeve for Leg Prosthesis
Authors: Grubbs Rachel , Yough Matthew , Rose Olivia , Lee Anthony , Sicree Teresa , Tiari Saeed , Piovesan Davide 
Published: January 2020

Abstract
This paper presents the findings of the research and design of a heat generating thermal prosthetic sleeve. The goal of the project was to get the sleeve to be designed in a way that keeps a comfortable temperature of the amputation site. Heat transfer analysis as well as comfort tests were used to select the optimal materials for the body of the sleeve. A series of electrical tests using multimeters were used to determine which heating element should be used, as well as in which orientation they should be connected. A microcontroller system had also to be selected to give the sleeve some adjustability.
Design and Fabrication of a Universal Gripper for Children With Special Needs
Authors: Vijaya Kumar Ajay Kumar , Schweitzer Emily , Baer Julie , Piovesan Davide 
Published: January 2020

Abstract
One in every sixty-eight children in the United States is affected by autism or another form of developmental disability. For children with autism it is difficult to learn the basic hand movements, which are required for gripping and holding objects of complex shapes. Our goal was to help these children by designing an ergonomic, simple, and easy to use interface that can be used to grasp desired objects of various shapes. This grasper translates a full hand power grip to a more fine-tuned precision grip. The sphere-shaped interface design outperformed all other shapes when used as the ergonomic side to be grasped by the children. Using 3D software modeling, we were further able to fine tune the interface for ease of use, manufacturing, and robustness.
Experimental Study on Effects of Operational Parameters on a Single-Cell Test-Bed Vanadium Redox Flow Battery
Authors: Islam Rabiul , Jeong Kwangkook 
Published: January 2020

Abstract
This paper describes the experimental characterization of a laboratory scale single-cell vanadium redox flow battery (VRFB) with variations of operational parameters. The single cell was experimentally investigated with respect to energy storage capacity, charge-discharge time, voltage, coulombic and energy efficiencies under various operating parameters such as current densities, electrolyte flow rates, and the ratio of electrolyte volume in electrolyte storage tank and cell. It was found that the voltage efficiency was increased by 11% entailing energy efficiency improvement from 60 to 66% as the electrolyte flowrate was increased from 40 to 220 ml/min. The highest columbic efficiency was achieved at 96% for the current density of 40 mA/cm2 which was 14% higher than that of the current density of 15 mA/cm2. Energy storage capacity was linearly increased with higher ratio of tank to cell volume due to the larger number of vanadium ions present. The improvement in energy storage capacities was observed to be 60, and 41% as the ratio was raised by 67, and 40%, respectively.
Experimental Characterization of a Novel Piezoelectric Fan
Authors: Benner Jingru , Shilyuk Eric , Coletta Jarrod , Mortazavi Mehdi , Santamaria Anthony D. , Su Shun , Nguyen Tony 
Published: January 2020

Abstract
Piezoelectric fans have attracted attentions in the past decades because of their low energy consumption, low noise level, light weight and reliability. A novel form of piezoelectric flapping fan is characterized experimentally and numerically. An experimental setup was built to measure the pressure and flow rate of piezoelectric fans with low static pressure at various frequencies. The fan performance curve was established. A high speed camera system was used to analyze the oscillation motion of the fan wings. The displacement of the leading edge and trailing edge of the piezoelectric fan wings are used as inputs to describe the deflection of the fan in the numerical model. The flow field obtained from the model is analyzed. The vortex shedding is observed and discussed. The pressure and flow rate obtained from the 2D numerical model are compared with the experimental results. The results provide a fundamental understanding of a piezoelectric fan with opposing oscillating wings.
A Decision Support Tool for Distributed Solar and Storage Investments: A Case Study in Austin, TX
Authors: Bandyopadhyay Arkasama , Conger Julia P. , Webber Michael E. , Leibowicz Benjamin D. 
Published: January 2020

Abstract
This study builds a decision support tool to evaluate when it is a good economic decision (least cost with minimum discomfort) for the residential customer to invest in distributed energy resources (DERs) based on different electricity rate structures, DER ownership frameworks, and DER rebates offered by electric utilities. The tool is demonstrated using empirical electricity consumption data from Pecan Street Inc. (a non-profit entity based on Austin, Texas), residential rates from Austin Energy (the municipal electric utility in Austin, Texas), DER ownership costs from various nationwide pilot programs, and incentives offered by electric utilities in the United States. Results show that for constant electricity rates, the overall expenditure is least when the customer owns solar panels without storage, while for time-varying pricing structures, the least expensive scenario is one where the customer does not own any DERs. As the capital costs for DERs decline, utilities incentivize customer ownership of DERs, and more residential customers face the decision of whether to invest in DERs, this study aims to be a key tool in aiding that decision-making process.
Thermal Behavior and Melt-Pool Dynamics of Cu-Cr-Zr Alloy in Powder-Bed Selective Laser Melting Process
Authors: Rahman M. Shafiqur , Schilling Paul J. , Herrington Paul D. , Chakravarty Uttam K. 
Published: January 2020

Abstract
Selective laser melting (SLM) is a growing additive manufacturing (AM) technology which is capable of rapidly fabricating functional components in the medical and aviation industries. The thermophysical properties and melt-pool dynamics involved in the powder-bed SLM process play a crucial role to determine the part quality and process optimization. In this study, a 3-D computational fluid dynamics (CFD) model with Cu-Cr-Zr (C-18150) powder-bed is developed incorporating a moving conical volumetric heat source and temperature-dependent thermal properties to conduct the Multiphysics simulations of the SLM process. The melt-pool dynamics and its thermal behavior are investigated numerically and results for temperature profile, cooling rate, variation in density, thermal conductivity, specific heat capacity, and velocity in the melt pool are obtained for different laser beam specifications. The validation of the CFD model is conducted by comparing the simulation results for temperature and the melt-front motion with the analytical results found from the classical Stefan problem of the phase-change material. Studying the process parameters, melt-pool geometry, and thermal behavior of Cu-Cr-Zr alloy can generate valuable information to establish Cu-Cr-Zr as a low-cost engineering material in the AM industry.
Analysis of Bio-Inspired Structures for 3D Force Sensing Using Virtual Prototyping
Authors: Alotaibi Ahmed M. , Anwar Sohel 
Published: January 2020

Abstract
3D force sensors have been proven its effectiveness and appropriateness for robotics applications. It has been used in medical and physical therapy applications such as surgical robot and Instrument Assisted Soft Tissue Manipulation (IASTM) in the recent times. The 3D force sensors have been utilized in robot assisted surgeries and modern physical therapy devices to monitor the 3D forces for improved performances. The 3D force sensor performance and specifications depend on different design parameters, such as structural configuration, sensing elements placements, and load criterion. In this paper, different bioinspired structure configurations have been investigated and analyzed to obtain the optimal 3D force sensor configuration in terms of structural integrity, compactness, safety factor, and strain sensitivity. Finite Element Analysis (FEA) simulation was used for the analysis to minimize the time of the development cycle.
Investigation on Mechanical Properties and Corrosion Resistance of Cobalt-Based Alloy Cladding Layer
Authors: Jin Zhiyi , Yao Zhenqiang , Shen Hong 
Published: January 2020

Abstract
Austenitic stainless steel was cladded with Cobalt-based alloy by means of Tungsten inert gas (TIG) welding to improve the performance of the working parts such as the thrust bearing plates under dynamic loads and corrosive liquid. Specimens were prepared with different welding parameters, namely the cladding current, preheating temperature, inter-layer temperature and post heat treatment temperature, so as to investigate their influence on micro-hardness, as well as tensile and bending strength. It is revealed that the lower welding current coincides with higher micro-hardness as well as tensile and bending strength. The higher inter-layer temperature will result inhigher overlay micro-hardness. The post weld heat treatment temperature influences the bending strength of the overlay weld specimens. In addition, the accumulation of Cr and Ni compounds on weldment surface is found to coincide with higher corrosion resistance in over-layers by means of XRD.
A New Trefftz Based Finite Element for Static Analysis of Laminated Composite Structures
Authors: Dwibedi Subhasankar 
Published: January 2020

Abstract
Composite materials have been widely used in industries for several years owing to their capability to perform better than homogeneous isotropic materials. Numerical tools like finite element method are efficiently used for analysis of structures made of composite materials. However, for complex shapes or geometries of structures, it becomes uneconomical (computational resource wise) to use Rayleigh-Ritz based finite element analysis. An unique Trefftz based finite element has been developed in this article to efficiently fill the gap in the above mentioned scenario. Hybrid-Tefftz finite element method’s flexibility to use arbitrary shaped elements comes handy in modelling complex geometries. The developed hybrid-Trefftz finite element approach has been used on symmetric angle-ply laminated composite plate and the obtained results have been compared with bench mark solutions. The present method proposes an approach for development of hybrid-Trefftz type finite elements, by which analysis of antisymmetric structures is also possible, an area of research which has been less explored by such approach as revealed from survey of available open literature.