bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flame Stability in Inverse Coaxial Injector Using Repetitive Nanosecond Pulsed Plasma
Authors: Zare Saeid , Lo Hao Wei , Roy Shrabanti , Askari Omid 
Published: January 2020

Abstract
There has been recently a growing interest in the use of methane as a strong candidate for both interplanetary and descent/ascent propulsion solutions. The higher boiling point and higher density of methane compared with hydrogen, makes its storage tank lighter, cheaper and smaller to launch. Methane is abundant in the outer solar system and can be harvested on Mars, Titan, Jupiter, and many other planets and therefore, it can be used in reusable rocket engines. However, there are still some technological challenges in methane engines development path. Among those challenges, ignition reliability and flame stability are of great importance. These challenges can be addressed by integrating low-temperature plasma (LTP) through repetitive nanosecond pulsed (RNP) discharge to the injector design. This research work focuses on Air/CH4 jet flames in a single-element coaxial shear injector coupled with RNP plasma discharge to study the influence of LTP on ignition characteristics and flame stability using advanced diagnostic techniques. The experiments have been performed for different fuel composition, jet velocities, discharge voltages and frequencies at atmospheric conditions. The transient flame behavior including flame oscillation is studied using direct photography by CMOS high-speed camera. The effect of plasma discharge location on flame stability is also investigated. To demonstrate the effectiveness of RNP discharge on liftoff and blowout/blowoff velocities, the jet velocity at the critical conditions is measured in terms of discharge frequencies and the enhancement of flame stability is then evaluated. The collected experimental data have shown that the RNP discharge can significantly extend the flame stability by reducing the liftoff height and increasing the velocity at which blowout/blowoff occurs.
Detailed Chemical Mechanism Generation for Combustion of Ethanol-Air Mixture
Authors: Roy Shrabanti , Hadi Fatemeh , Askari Omid 
Published: January 2020

Abstract
Significance of ethanol as an alternative source of renewable energy is increasing every day. In this study a chemical mechanism has been developed to predict the characteristic of ethanol oxidation in a wide range of temperature and pressure of 300–2500 K and 1–50 atm, respectively. The mechanism is generated using reaction mechanism generator (RMG). Sensitivity analysis on the mechanism is done to find the reactions responsible in the deviation of numerical results with experimental data. Rate coefficient of important reactions is corrected with well-accepted data from literature which helps to improve the mechanism against experiment. The validation is done with laminar burning speed and ignition delay time results at various operating conditions. The results show a reasonable agreement in both high pressure and low temperature cases. A good prediction of major species concentration is found in flame structure measurement. A comparison of the current mechanism with other available chemical mechanisms is also presented at different operating conditions. Compared to other mechanisms, this improved mechanism has an advantage of handling the high pressure and low temperature operating conditions within a reasonable time and accuracy.
Leidenfrost Phenomenon and its Impact on Sessile Drop Evaporation for Different Liquids and Surfaces
Authors: Ahmed Pranzal , Amin M. Ruhul , Ali Mohammad 
Published: January 2020

Abstract
Recent study of the applications of the Leidenfrost effect has sparked renewed interest in this phenomenon. Due to Leidenfrost effect, a droplet can be levitated by its own vapor layer on a sufficiently heated surface. In this work an experimental investigation has been performed to determine the Leidenfrost point (LFP) of different liquids on different surfaces. Copper, aluminum and brass plates were used with water, methanol, and ethanol as different liquids to study the variation of LFP. The experiment was conducted with incident droplets of water, methanol, and ethanol on the three different metal blocks which were heated by cartridge heaters. The input powers in the heaters were varied by a voltage variac. At each temperature, droplet evaporation time was recorded where the highest evaporation time corresponded with the LFP. For the ranges of parameters considered in this study, the Leidenfrost temperature for water varied from 180°C to 200°C. For organic fluids like methanol it varied from 160°C to 200°C while for ethanol it varied from 160°C to 200°C. These findings are important because accurate modeling of Leidenfrost phenomenon is crucial for the design of many cooling devices. If a vapor layer is present between the liquid and the surface to be cooled, then the cooling becomes inefficient. This is especially important for the rapid cooling of overheated components in high power density systems, such as nuclear reactors and other devices.
Design of Metacarpophalangeal Single-Piece Joint Prosthesis to Increase Motion in Abduction/Adduction
Authors: Millard Nathan , Yee Raymond K. 
Published: January 2020

Abstract
One of the leading causes of disability is rheumatoid arthritis (RA), especially that of the hand, the metacarpophalangeal (MCP) joint being affected the most. Current single piece prostheses are designed to allow for motion in flexion and extension, but little effort is put towards motion in abduction and adduction. The objective of this study is to determine the effects of web (hinge) joint cross-sectional geometry on stress, strain, shear strain, strain energy, and reaction moment magnitude for an MCP joint that is subject to not only flexion and extension but also abduction and adduction. Using finger bone dimensions from the literature, geometry was produced in ANSYS finite element software. The geometry was assigned a hyperelastic material constitutive model, making the analysis nonlinear. The cross-sectional shape of the hinge was controlled by ellipse dimensions, one for thickness and one for width. Motion boundary conditions were applied to the distal portion of the model resulting in bending at the hinge. The study showed that for flexion/extension motion the von Mises (equivalent) stress, shear strain, and equivalent strain are linearly proportional to the thickness but inversely proportional to the width. The reaction moment and strain energy are linearly proportional to the thickness but exponentially proportional to the width. For motion in abduction and adduction the behavior is opposite; the width acting as the thickness does in flexion/extension motion and the thickness acting as the width does in flexion/extension motion. It was also seen that high levels of shear strain develop on the palmer side of the model, indicating that failure has the most potential to occur in that area.
The Mechanical Response of a Cantilever Beam With an Embedded Crack With Non-Linear Crack Surface Closure Effects
Authors: Fang Xiaomin , Charalambides Panos G. 
Published: January 2020

Abstract
This study addresses the crack surfaces closure effects of a cracked cantilever beam subjected to transverse force applied at its free end under static loading. A crack closure method is developed as needed to account for crack surface contact in regions wherein the linear solutions predict physically inadmissible crack surface inter penetration. An efficient finite element algorithm is developed accordingly to solve the static problem of the beam containing a fully embedded sharp crack in a linear, elastic, homogeneous and isotropic system. Emphasis is placed on the comparison between the near-tip fracture characteristics estimates, e.g. the normalized energy release rate, Mode I and Mode II stress intensity factors (SIF), and mode mixity, with closure effects and those without closure effects reported elsewhere. The crack length, orientation, and crack center location appear as the studied model parameters of a beam of fixed beam aspect ratio. In addition, based on the study observations of pure Mode II crack, a case study on the beam with an embedded vertical crack in the compressive regime is reported to show the deformed profiles due to full crack surfaces closure during loading. The curvature profile of the cracked beam with and without closure effects are compared to those of the healthy beam for the application of closure effects in improving the results accuracy.
Thermal Transport in Actinide Oxide Fuels With Interstitial Defects
Authors: Mitchell Katherine , Horner Hunter , Resnick Alex , Park Jungkyu , Farfán Eduardo B. , Yee Tien , Hummel Andrew 
Published: January 2020

Abstract
Molecular displacement occurs in the oxide fuels of nuclear reactors during operation. This causes several types of point defects to be generated inside the oxide nuclear fuels. To improve the safety and efficiency of nuclear reactor operation, it is necessary to better understand the effects of point defects on the properties of the oxide fuels. In this study, we examine the effects of interstitial defects on thermal transport in two representative actinide oxides used in modern reactors (UO2, and PuO2). Reverse non-equilibrium molecular dynamics (RNEMD) is employed to approximate the thermal conductivities for the aforementioned fuels at several sample lengths and at defect concentrations of 0.1%, 1%, and 5%. The results show that alterations to the lattice structures of these fuels reduce their thermal conductivities significantly. For example, oxygen interstitial defects at concentrations even as low as 0.1% decreased thermal conductivity by 20% at 100 units for each fuel.
Investigation of Surface Characteristics and Chip Morphology in High Speed Cutting of Inconel718 Based on SHPB System
Authors: Wang Zengqiang , Zhang Zhanfei , Wang Wenhu , Jiang Ruisong , Lin Kunyang , Xue Hongliang , Guo Biao 
Published: January 2020

Abstract
High speed cutting (HSC) technology has the characteristics of high material removal rates and high machining precision. In order to study the relationships between chip morphology and machining surface characteristic in high speed cutting of superalloy Inconel718. High-speed orthogonal cutting experiment are carried out by used a high speed cutting device based on split Hopkinson pressure bar (SHPB). The specimen surfaces and collected chips were then detected with optical microscope, scanning electron microscope and three-dimensional surface profile measuring instrument. The results show that within the experimental parameters (cutting speed from 8–16m/s, depth of cut 0.1–0.5mm), the obtained chips are sawtooth chips and periodic micro-ripple appear on the machined surface. With the cutting speed increases, machining surface roughness is decreases from 1.4 to 0.99μm, and the amplitude of periodic ripples also decreases. With the cutting depth increases, the machining surface roughness increases from 0.96 to 5.12μm and surface topography becomes worse. With the increase of cutting speed and depth of cut, the chips are transform from continues sawtooth to sawtooth fragment. By comparing the frequency of surface ripples and sawtooth chips, it is found that they are highly consistent.
Characterization of GRE Pipes Fatigue Failure Subjected to HTHP Loading Conditions
Authors: Abdo Jamil , Hassan Edris , Kwak Jan 
Published: January 2020

Abstract
GRE composite pipes are a great substitute for Carbon steel, however, obstacles of introducing GRE composite pipes into oil and gas transmission lines have been primarily related to inadequate testing data to maintain materials’ extended performance and pipes fatigue failure characterization. Customized testing facility has been designed and fabricated to substantiate design of GRE pipes under controlled service conditions. The testing procedure was conducted based on ASTM and ISO Standards. Pipes filled with crude oil were placed in a thermal and pressure enclosure at a temperature of 65°C and an internal pressure of 130 bars for 1000 hours and fatigue failure behavior of the GRE pipes were investigated. Pipes with a surface crack a/t = 0.5 and 0.3 were exposed to alternating internal pressure of 25 cycles/min and a load ratio of R = 0.05. Fatigue tests were performed at two load levels: 50%, and 30% of the pipes strength under static internal pressure.
Results show that the GRE pipes burst suddenly without any leakage when the internal pressure was high, however, the pipe exhibit leakage first and then fails when the internal pressure was low. The maximum fatigue life obtain for GRE reference and HTHP specimen pipes in the crack region were 72,237 cycles and 73,107 cycles, respectively, with applied 0.5 static internal pressure (102 MPa) and a/t = 0.3 ratio. The minimum fatigue life obtained in the crack region are 14,105 cycles and 13,627 cycles for GRE reference and HTHP specimen pipes, respectively, with applied 0.5 static internal pressure (170 MPa) for a/t = 0.3 ratio.
Research on Flywheel Battery With Flux Switching Permanent Magnet Motor and its Application on Servo Press
Authors: Liu Chen , Zhao Shengdun , Dong Peng , Zhang Peng 
Published: January 2020

Abstract
Servo press is a manufacturing machine that usually works under impact loads. Flywheel battery is an energy storage device that has been widely studied in recent years. In this paper, a flywheel battery system for servo press energy compensation was put forward. In considering the efficiency and structure robustness, the flux switching permanent magnet (FSPM) motor is appropriate for flywheel battery as energy conversion device. In this study, the flywheel battery structure and working principle were first described. Then the motor characters were analyzed by FEM. After that, a simply initiative power control strategy was introduced for the flywheel battery. Finally, the prototype of flywheel battery with FSPM motor was made and connected to a servo press’s motor driver. The experiments were taken with and without the flywheel battery respectively. The experiment results proved that the flywheel battery could compensate a certain of DC link voltage loss during the press stamping process. That makes the servo press’s driven motor has a more stable power source and reduces the electrical shock to other equipment. In conclusion, the flywheel battery with FSPM motor is an effective energy storage system for servo press. It is believed that with the miniaturization and simplification of flywheel battery, the flywheel battery will be more general in impact load devices.
Effects of Gravity Level on Morphology of Laminar Double Flames
Authors: Chen Tao , Liu Yu Cheng 
Published: January 2020

Abstract
Laminar double flames exist in many combustion configurations involving non-premixed or partially-premixed combustion processes. These flames can exhibit a “double-branched” structure due to local mixing in a non-premixed fuel and oxidizer flows. The dynamics and morphology of double flames in a convective flow could be significantly influenced by buoyancy driven convection such that various strengths of gravitational field may lead to complete different flame behaviors.
In this work, double flames generated at the flow nozzle of a slot burner were investigated using the open source software, OpenFOAM®. A two-dimensional simulation was used to replicate the geometric feature of a slot-burner flame. Conditions of interests include five different gravity levels with and without radiative heat transfer. Through analyzing the spatial distribution of velocity, temperature, heat release rate and species, the difference of double flames at different gravity levels were studied. The results show that higher gravity levels appear to entrain the cool surrounding fluid through buoyancy effects, which is indicated through obvious negative x-velocity region. The heat release rate and OH radical information are used to explain intrinsic behaviors of diffusion flame and premixed fuel-rich branches.
Design of a Composite Mountain Bike Hydraulic Disc Brake
Authors: Rahman AHM E. , Pugh David 
Published: January 2020

Abstract
The primary goal of the project is to design a hydraulic disk brake system for mountain bikes made from reinforced plastics. Hydraulic brakes offer significantly better performance for a mountain bike over traditional cable rim break or cable disk break. Nevertheless, people are unable to appreciate advantage because of the price. The traditional hydraulic disk brake systems are made of aluminum alloy. With a proper design, it may be possible to create a lever assembly and a caliper that would be competitive on price and weight. Often bike parts are judged by how much they weight, the less they weight, the more they are desirable. This is only true to a certain extent because lighter parts come with a premium price tag. The current project proposed that the injection molded brakes would be lighter because of the material being used and cost-effective because the manufacturing process can be utilized. Commercial reinforced plastic composites have been identified as lighter materials compared to aluminum alloy. Through an iterative design process, the final designs of lever assembly and caliper have been achieved. The stopping force has been determined considering the abrupt stoppage with a standard weight person riding the bike. Based on the stopping force the stress analyses were obtained using FEA simulation for master cylinder, slave cylinder, and lever. At the end, the final designs were chosen based on the stress analyses and manufacturability.
Variation Analysis for Composite Parts With Considering Local Delamination Defects
Authors: Liu Jinyu , Li Zhimin , Liu Tao , Li Xinxin 
Published: January 2020

Abstract
Laminate composite components have been widely used in engineering fields, such as aerospace and aircraft fields, automotive industries, marine and civil engineering. Due to inherent properties of laminated composites, the effects of local delamination defects will result in a decrease of assembly dimensional precision and mechanical property, and a variation analysis considering the effect of delamination defects become increasingly indispensable. In order to understand the influence relationship between delamination defects and manufacturing deviations, a methodology based on the method of influence coefficients is proposed to analyze the influence relationship between delamination defects and manufacturing deviations. Then, local delamination modes are developed based on the interface deformable bi-layer beam model with consideration of transverse shear and delamination tip deformations. This model provides an accurate solution with the delaminated composite structures. Finally, the effect of local delamination length ratio (a/h) has been further studied for the assembly precision analysis based on the flexible joint model, and the comparison of simulation result shows that the delamination has a signification influence on the structural performance and the quality of the product.
Strain and Photovoltaic Sensitivities of Dumbbell-Shape GNR-Base Sensors
Authors: Goundar Jowesh Avisheik , Kudo Takuya , Zhang Qinqiang , Suzuki Ken , Miura Hideo 
Published: January 2020

Abstract
The area-arrayed dumbbell-shape Graphene Nano-Ribbons (GNRs) were fabricated by using chemical vapor deposition and photolithography technologies. The electronic behavior of the fabricated GNR-FET structure was evaluated for its photonic properties with an incident light intensity of 1-mW. The 200-nm wide GNRs structure showed metallic properties, while those with the width of 40 nm showed semiconductive properties as was expected. The light-induced photocurrent was observed in all the fabricated GNRs structures. The average photocurrent observed in the 2-mm wide graphene structure was 3.3 A/m2 and that observed in the 40-nm wide area-arrayed GNRs structure was 261 A/m2, respectively. Based on this photocurrent, the external photosensitivity of the 40-nm wide GNRs structure was about 2.6 × 105 A/W.m2 and this value was much larger than that of conventional Si-base solar cells. In addition, the effect of strain on the resistivity of GNRs was measured. Uniaxial tensile strain was applied to the area-arrayed GNRs structures with the width from 200 nm to 40 nm. The gauge factor obtained from the GNRs with the width wider than 100 nm was about 3, and that with the width of 40 nm was about 160. Therefore, highly-sensitive strain sensors can be realized by using GNRs thinner than 70 nm.
Dynamic and Static Fracture Toughness of Al/Epoxy Resin Interface
Authors: Saito Yusaku , Sudo Kosuke , Kanamori Kohei , Yonezu Akio 
Published: January 2020

Abstract
This study evaluates the interfacial fracture strength and toughness of an epoxy resin/aluminum alloy based on two different tests of impact loading and quasi-static loading. In the impact test, we carried out the Laser Shock Adhesion Test (LaSAT). This method uses a strong ultrasonic wave induced by pulsed laser irradiation to induce interfacial fracture. Due to the grease layer ablation caused by laser irradiation, strong elastic wave generates and propagates. The tensile stress acts on the Al/epoxy resin interface, inducing an interfacial delamination. This delamination is further extended by an additional laser irradiation in order to evaluate the interfacial fracture toughness. By simulating the experimental delamination progression in FEM (Finite Element Method), we evaluated the dynamic fracture toughness of the Al alloy/epoxy resin interface. On the other hand, a quasi-static test for the toughness evaluation was conducted using a uniaxial tensile test. Before the tensile test, we produced an initial crack (initial delamination) at the interface by using laser ablation. Subsequently, this sample having initial crack is loaded by uniaxial tension. It is found that the interfacial crack progresses, resulting in unstable interfacial fracture. Furthermore, we conducted FEM simulation, in order to estimate the stress distribution near the delamination. By deriving a stress intensity factor from the stress distribution, we evaluated the quasi-static fracture toughness. To compare the dynamic and quasi-static fracture toughness of Al alloy/epoxy resin interface, we clarified the loading rate dependency of interfacial fracture toughness.
Self-Synchronization in a Class of Motor Driven Reciprocating Mechanisms
Authors: Sinha Anubhab , Bharti Saurabh Kumar , Samantaray Arun Kumar , Bhattacharyya Ranjan 
Published: January 2020

Abstract
The phenomena of ‘self-synchronization’ is investigated in Reciprocating Mechanisms, namely — crank slider mechanisms. A typical crank-slider mechanism comprises a rotating crank, a sliding piston and a connecting rod in between them. A series of such mechanisms are installed inside a common vibrating base structure. Each of these mechanisms are independently powered by a DC motor. So, for ‘n’ number of mechanisms, there are also ‘n’ number of motors driving them. The assembly is then set up an SDoF vibrating system. A multi-body simulation model is developed on MSC Adams. The numerical study shows that even with different voltage inputs for each motor, the individual mechanisms ‘self-synchronize’ by attaining a single common driving speed. The synchronization is self-induced due to energy interactions between the non-ideal drives and the common vibrating base. Moreover, the tendency to synchronize is so strong that once synchronized, the mechanisms continue to do so even when one or more motors are switched off. The study demonstrates how synchronization can assist in driving multiple mechanisms simultaneously, possibly with minimal power requirements as well as reduced vibrations.