bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Shark Fluid Dynamics to Guide Satellite Telemetry Tag Development
Authors: Zarea Munir , Brown Evan , George Allen , Kozsey Joshua , Palmgren Tyler , Wu Meng-Chien , Oman Sarah , Parmigiani John , Piacenza Joseph , Piacenza Susan
Published: February 2023

Sharks are powerful predators that make long-range migrations across vast swaths of the ocean. Scientists attach satellite telemetry tracking tags to sharks in order to gather data on behavior, movement patterns and habitat usage. However, hydro-dynamic loading from these tags may unintentionally influence the host shark’s behavior, although the extent of the loading is still not well understood. While tag manufacturers have made incremental improvements to make tags lighter and smaller, there is still not a clear understanding between tag design and host animal impacts. This fundamental knowledge gap makes the design of telemetry tags difficult when aiming to minimize hydrodynamic effects. In this paper, we present an approach intended to help inform tag design. In addition, a case study demonstrates this approach using 3D digital models discussed in the introduction. Four different shark species: the great hammerhead (Sphyrna mokarran), shortfin mako (Isurus oxyrinchus), blacktip reef (Carcharhinus limbatus), and Caribbean reef (Carcharhinus perezii). We used computational fluid dynamics (CFD) methods to estimate baseline drag and lift coefficients from a range of angles of attack to simulate the sharks ascending, descending, and swimming horizontally. We solved lift and drag coefficients through force reports integrated into the CFD software, STAR-CCM+. The simulations were solved with the Menter shear stress transport (SST) k-ω turbulence model at steady-state. Across species, the drag and lift coefficients ranged from 0.14 – 0.21 and −0.02 – 0.37, respectively. To visualize the fluid dynamics, we created plots of pressure distribution and fluid flow associated with each shark’s average cruising speeds, providing insight for future researchers investigating optimal tag placement that minimizes the tag’s impact. To validate the computational models, we performed wind tunnel testing by using 3D printed models of each shark, allowing us to empirically measure lift and drag forces. A three-axis sting-balance style measurement system with strain gauges was used, while considering wind speed, fluid density, and matched Reynolds numbers associated with the CFD models for each species. Finally, we statistically compared the computational and wind tunnel measurements. Moving forward, we will explore the changes in drag and lift with different satellite tag models attached to the shark species. Our findings will support development of a methodology to quantify the hydrodynamic impact of different tag designs on sharks. This can be used by future researchers to determine the lift and drag forces a shark experiences with a satellite telemetry tag attached. Ultimately, this information will help to better monitor sharks in their natural environment and provide information that can be useful to the conservation of the species.
Investigation on the Impact of Morphology and Arrangement of Graphene Nanoplatelet on Mechanical Behavior of Epoxy Nanocomposites
Authors: Aluko Olanrewaju
Published: February 2023

This research study addresses how the arrangement and morphology of the Graphene nanoplatelet (GNP) impacts the properties of epoxy nanocomposites using polycrystalline theory and micromechanics. The effective properties of the macroscopic epoxy network were used as inputs with GNP properties in the micromechanical model. Generalized Method of Cells (GMC) was applied to evaluate mechanical properties of the nanocomposites. The obtained results showed that the morphology and the arrangements of inclusions in epoxy have significant impact on the mechanical behavior of GNP/epoxy nanocomposites. The results of the simulations provide an understanding of the link between the morphology, the arrangement of the reinforcements, and the composite performance. The methodology can be used to optimize the GNP/epoxy performance for different engineering applications in automotive and aerospace industries.
Crushing Analysis of Square Tube With Fluid and Foam-Filled Cellular Core
Authors: Jenson Sean , Ali Muhammad
Published: February 2023

Passenger vehicles are constantly being redesigned to maximize occupant safety in the event of a collision. Changes and improvements to automobiles have resulted in a significant amount of energy absorption capability through the vehicle chassis. Axial crushing members are often deployed in vehicle front end and side chassis structures and are designed to absorb a maximum amount of energy before complete deformation. These structures experience a series of progressive folding during axial deformation resulting in moderate and relatively constant force throughout the crushing behavior. To increase the performance of these structures, different cross-sectional shapes and core materials have been investigated. The present study investigates the addition of graded cellular core structure with zones of crushable foam and fluid inserts within the cell voids. The addition of crushable foam material aimed to provide stability to the crushing behavior of the structure. The incompressible nature of the fluid insert provided sections of increased structural strength and a more global crushing response. The finite element approach was conducted using ABAQUS dynamic environment and the square crush tubes were subjected to dynamic axial crushing. Foam and fluid addition provided additional energy absorption while creating a more global deformation response.
Thermo-Mechanical Analysis of a Composite Tapered-Land Hydrodynamic Thrust Bearing Sector Manufactured Using Fused Filament Fabrication
Authors: Yasko Isaiah , Furuta Lloyd , Fais Collier , Ali Muhammad , Wisner Brian
Published: February 2023

This work investigates the use of carbon fiber filled polyamide filament as feedstock material for fused filament fabrication of hydrodynamic tapered-land thrust bearings. Experimental analysis was conducted on fused filament fabricated carbon fiber filled polyamide samples to obtain elastic properties and thermal expansion coefficients along the longitudinal and transverse directions with respect to the print orientation. Single bearing pads were modeled using the obtained mechanical properties and were then analyzed under in-service bearing operating pressures and temperatures. Thermo-mechanical analysis conducted in ABAQUS/CAE shows that taper geometry forms on both [0,90] and [0,0,90] print orientations with depths of 174 μm and 260 μm as a result of thermal expansion occurring from the heat load produced during hydrodynamic bearing operation.
A Study on 5-Axis Turning for Non-Axisymmetric 3D Surfaces
Authors: Ueda Narimasa , Ishizuka Akane , Morimoto Yoshitaka , Hayashi Akio , Kaneko Yoshiyuki , Suzuki Naohiko
Published: February 2023

A machining center is a common machine tool that can machine complex free-form surfaces such as the press mold, automobile’s cam profile. When these curved surfaces are machined by the conventional machining center and/or the grinding machine, it takes lot of time to complete with enough accuracy. In order to solve this problem, this study aims not only to improve the machining accuracy of this curved surface but also to make it possible to shorten the machining time using a CNC lathe. In this study, the NACS-Turning (Non-axisymmetric curved surface turning) method that we proposed originally was used. In this study, the spindle of C-axis, the moving table with the cutting tool of X1-axis, the other counter moving table of X2-axis, the spindle feed table of Z-axis, and the tool rotation axis of B axis are adapted. In this 5-axis machining method, all the axis are controlled with the synchronized manner. This method can machine the same rotational position of workpiece with the same cutting edge of the rotary tool. As an experiment, we compared 5-axis machining with synchronized spindle and tool rotation, 4-axis machining, and machining with non-synchronous rotation. Our new 5-axis machining method with synchronized spindle and tool rotation reduced the form error from 387μm to 360μm and the surface roughness from Rz 9.6μm to Rz 4.7μm compared to 4-axis. In 5-axis machining with synchronizing the spindle and the tool rotation, the surface roughness was reduced from Rz 15.9μm to Rz 4.7μm compared to the non-synchronous machining.
Numerical Investigation of Finite Element Lower Extremity Model Response in Blast Loading
Authors: Vikram Aman , Chawla Anoop , Mukherjee Sudipto
Published: February 2023

This study has investigated the response of Total Human Model for Safety (THUMS) lower extremity finite element model under blast loading. Response of the model was estimated in simulated underbody blast loading using a floorplate impact velocity of increasing severity. Correlation and Analysis (CORA) ratings suggested a good match between numerical response and available experimental data. Model response was then investigated in antipersonnel landmine explosion. The model was found stable in nearfield blast and sensitive to the threat definition. The lower extremity injury was predicted when detonation occurred below the heel. The model predicted major injuries localized to the hindfoot and midfoot with minimal damage to the forefoot, consistent with the findings in literature.
Multiple Flexoelectric Actuation and Control of Plates
Authors: Yang Xinyu , Zhang Jie , Fan Mu
Published: February 2023

Flexoelectric effect is a novel electro-mechanical coupling effect that has drawn a lot of attention in the past few decades. Compared with piezoelectric materials, flexoelectric materials have the inherent characteristics of gradient coupling effect between electric field and elastic field. Since no complex pre-polarization process is required, the flexoelectric materials do not have depolarization or aging problems during the trial period. Similar to piezoelectricity, flexoelectricity exhibits two different effects: direct and converse flexoelectric effect. The direct flexoelectric effect indicates that the strain gradient produces an electrical response, and can be used in sensor design and energy harvesting. The converse flexoelectric effect represents mechanical stress or strain caused by inhomogeneous electric field or polarization gradient, and then as a response, the induced membrane force and the corresponding control moment will occur in the structure.

This study will take the mechanic electric coupling characteristics of flexoelectric effect as the core, establish the dynamic equation, deduce the modal response of plate structure under the effect of flexoelectric and obtain the relationship between modal response and electric field gradient. To validate the theoretical method, a finite element model of flexoelectric actuated plate will be established in the commercial software COMSOL Multiphysics. With no existing flexoelectric module, the finite element model of flexoelectric plate will be built based on the original dynamic model. A non-uniform electric field is firstly constructed in COMSOL with the electrostatic module. The influence of different structural parameters on the vibration control effect caused by flexoelectric excitation will be analyzed and optimized, which will provide a theoretical basis for the application of flexoelectric materials in the vibration control of novel smart structures.
Exploring the Potential Role of Prunus Domestica in Corrosion Inhibition of AA6063-T5 Aluminium Alloy in Sodium Chloride Media
Authors: Sanni Omotayo , Ren Jianwei , Jen Tien-Chien
Published: February 2023

Aluminium is a material of choice in the industry for numerous applications due to its excellent properties. Unfortunately, the films formed are amphoteric and break when exposed to alkali and strong acid, making aluminium corrode. Diverse techniques have been used in mitigating aluminum against corrosion; product fluid blending, upgrading materials, chemical inhibition, and process control. Among these techniques, the use of inhibitors is considered one of the cheapest and most convenient means to fight corrosion, especially in chloride environments. Several organic and inorganic inhibitors for corrosion protection processes have been utilized in the industry, unfortunately, most corrosion inhibitors used in the industry are toxic and expensive, research has recently moved in the direction of nontoxic and low-cost inhibitors. Therefore, in the present work, the corrosion inhibition of AA6063-T5 aluminium alloy in sodium chloride (3.5% wt) solution by Prunus Domestica extract was studied. Electrochemical impedance spectroscopy, potentiodynamic polarization, and gravimetric techniques were utilized in this study. Scanning electron microscopy and energy dispersive X-ray techniques were employed to describe the surface morphology and elemental analysis, respectively. The results demonstrated that the presence of Prunus Domestica inhibits the corrosion of AA6063-T5 aluminium alloy with 99.01 % efficiency. The high corrosion resistance and low values of corrosion current, obtained from the electrochemical impedance spectroscopy, potentiodynamic polarization, and gravimetric experiments, affirmed the adequacy of Prunus Domestica as an excellent corrosion inhibitor for AA6063-T5 aluminium alloy.
Waste Disposal Plant Application of Overhauled and Regenerated Steam Turbine
Authors: Capata Roberto , Calabria Alfonso , Reale Michele
Published: February 2023

The present work aims to evaluate and identify the methodology for reusing disused steam turbines in waste-to-energy plants. First, the methodology for assessing the state of the turbine will be identified through a complete overhaul of the same turbine, with attention to the components subjected to greater wear, to evaluate the possibility of reconditioning. The reference turbine will be a disused, malfunctioning and old-tech machine, often considered as “waste”, but with great potential, such that it was evaluated and finally decided to enhance it through reconditioning. The turbine overhaul operations are characterized by a first analysis of the typical failures of steam turbines, identifying the components most exposed to breakage and a deep accurate inspection has been carried out. To accomplish this task, it is necessary to know, through a completed study, the “history” of the machinery, identifying the components of the steam turbine with the highest incidence of failure. Consequently, the frequency of occurrence and the severity of the damage can be evaluated. It will be necessary to put attention to the components that present a greater risk of breakage, identifying the checks to be carried out. All possible fault chains will then be studied, highlighting the main cause and the various maintenance periods to which the turbine has been subjected. Once the functionality of the turbine has been verified, the possibility of its reuse will be evaluated, for example for geothermal plants or for waste-to-energy. Once the turbine modernization operations have been completed, the possibility of its reuse in a waste treatment plant will be analyzed. So, a pilot power plant will be studied and the possibility of using the modernized turbine within the same plant will be verified, evaluating through simulations (not included in this work) the actual feasibility and functionality of the choice made. Given the current trend in the cost of energy is growing, with a consequent increase in revenues obtainable from the use of a reconditioned turbine, a comparison of the profits deriving from the use of a revised turbine compared to the new one, also considering the time necessary for economic recovery, will be carried out. In the present work, therefore, authors wanted to underline the importance of treating waste as a source of added value (in this case the disused driving machine) and a source of energy (municipal solid waste), rather than as tasks that inevitably weigh on the finances of the State and of the individual citizen. Finally, the main goal of the work has been achieved. In fact, proven by the data, it is possible to reuse turbines after having overhauled them and take advantage in different plant applications.
Non-Destructive Evaluation of Embedded Cracks in Metal by Ultrasound: Experimental Investigation
Authors: Habib Abir Sk. Yasin , Rahi S. H. M. Muntasir , Hasan Mohaimenul , Paul Titan Chandra
Published: February 2023

Embedded cracks of different type of samples of mild steel gas pipe API 1104 were identified and sized using Non-destructive evaluation. A procedure to create these embedded cracks inside the sample was developed. The UH-F1000knX hydraulic universal testing machine was used for bending and arc welding was done for bidding. 21 samples of different thickness and crack size were physically made. They were machined in shaper and grinding machine. A special reference slit of known deformity size was made to calibrate the ultrasonic testing machine’s sensitivity. EPOCH-650 ultrasonic testing machine was used to identify and measure these defects. Both normal and shear waves were used. Contact probe was used. Using the fabricated reference slit 4 different curves of deformity size (mm) vs Eco amplitude (%) were developed. Each of them provided a 3rd-degree polynomial equation. Amplitude Comparison Technique (ACT) and Amplitude Distance Differential Technique (ADDT) was used to size the deformities. For each shear wave an eco-amplitude (%) vs constant (c) curve was developed. Validation was done by destructive testing. For identifying deformities, around 95% accuracy was obtained and for sizing the deformities almost 60% accuracy was obtained. 35° and 45° shear waves gave 72% and 43% accurate data respectively.
Model of Angular Object Positioning Process by a System of Oblique Friction Force Fields on Parallel Planes
Authors: Piatkowski Tomasz
Published: February 2023

The paper concerns modelling of the angular positioning process of cuboidal objects by means of a system of two oblique friction force fields generated by conveyor belts located on parallel planes. The novelty of the research is discretization of the deformable contact surface of the object base with the friction force fields and the use of oblique infeed conveyors with two variants of inputs: angular and straight. It was assumed that the object, while moving between oblique conveyors at different heights, performs a 3D movement. The object is treated as a rigid body with a soft base, edges and corners that can be subjected to significant local deformations. A modified nonlinear Kelvin model was used to describe the normal reaction forces at the contact points of the object with the bearing surfaces of the conveyors, and the static Bengisu-Akay friction model represents the tangential forces. Research shows that the use of a slight offset between the bearing surfaces of the conveyors and the highest possible proportion between the motion velocities of the infeed and outfeed conveyors have positive effect on improving the angular precision of the positioned objects. The results of the research have practical application in the design of high-performance conveyor transport systems, used in the processes of picking cuboidal objects, requiring a strictly defined angular orientation.
Effects of Corner Radii on Vortex-Induced Vibration With Forced Convection Heat Transfer From Angled Tandem-Cylinder at Low Re
Authors: Sarout Yuvraj , Islam Md , Janajreh Isam
Published: February 2023

Flow-induced vibration (FIV) of the modified tandem-cylinder with a change in corner radii has been investigated in a laminar flow regime with Re = 150 and Pr = 0.7. The corner radius (r: corner radii, R: cylinder characteristic length) r* = 0, 0.5, 0.75 and 1 are used at a constant angle of attack of 45°. The cylinders are allowed to vibrate in transverse direction while restricted in axial direction with spacing ratio L/D = 4. Computation is carried out with a fixed mass ratio m* = 10 and varying reduced velocity Ur = 2 ∼ 10. Constant heating is provided by keeping boundary at a constant temperature. The two-dimensional incompressible Navier-Stokes equations and energy equation are coupled together. Navier-Stokes equations are used with FIV equation of elastically supported cylinder to have flow solutions. Lock-in phenomenon for most of the configuration is occurring at Ur = 6 where vibrational amplitude for most of the configuration is peaked. At Ur = 6 for square cylinder, pseudo ‘2P’ can be observed in the wake of r* = 0. Vortices at Ur = 6 are not merged properly to form a definite type of vortex shedding, although in further downstream weak 2S vortex shedding can be observed. Heating of cylinder is affected by various parameters such as corner radii and spacing ratio with other factors such as early flow separation, reattachment, and vibrational amplitude. Maximum values of Average Nusselt number Nuavg is at Ur = 6 for circular cylinder, whereas minimum lies at Ur = 2 for square downstream cylinder. Results give a deep insight into heat transfer getting changed by changing different parameters and will make a base for future study of tube bundles in heat exchangers with FIV.
Simulating Aerodynamic Effects of Location and Orientation of Bicycles Mounted on Sedans
Authors: Goodrich Sarah , Perez-Raya Isaac
Published: February 2023

Biking is a common activity, and many people want or need to drive their bike to different locations, necessitating a bike rack to easily transport it. Choosing a bike rack relies on cost, car type, and mounting ease. One of the aspects of choosing a rack that is less studied is the aerodynamics and effect on gas mileage and pollution. This paper describes the methods and results of simulations in ANSYS-Fluent, comparing the aerodynamics of different racks and bike positions on a car. Three simulations were done, one with just the car, one with a bike mounted on a roof rack, and one with a bike mounted on a trunk rack. After a mesh sensitivity analysis, determining a minimum mesh size, the three simulations were run with the same mesh and simulation settings to keep everything as similar as possible, with the geometries being the main difference between the simulations. Results were compared to similar simulations and values of the actual car. Results showed the car without bike as the most aerodynamic with a drag coefficient of 0.35, drag force of 335.8 N, and a gas mileage of 29 mpg, followed by the vehicle with the trunk rack with a drag coefficient of 0.37, drag force of 353 N, and gas mileage of 27.8 mpg, then the car with the roof rack with a drag coefficient of 0.40, drag force of 423 N, and gas mileage of 22.97 mpg. Overall, results show significant differences in the aerodynamic and environmental effects depending on the location and orientation of mounting a bike.
Evaluation of 3D-Printed Gel Using a Flat-Ended Square Indenter
Authors: Delgado Ana Isabel , Dong Pengfei , Gu Linxia
Published: February 2023

In this work, we provide a correction factor for quantifying the mechanical properties of soft biomaterials at the microscale with indentation test. Finite element (FE) models were developed to analyze the indentation test on the thin collagen layer. Based on the experiment setup, the indenter was simulated as a rigid flat-ended square indenter, the sample was simulated as a thin layer. The square indenter has a size of 2 × 2 mm and 3 × 3 mm, separately. For each indenter, the transverse dimension of the sample increased from smaller than the indenter size to 10 times the indenter size to quantify the relationship between the true stiffness and the nominal stiffness. Results have shown as the transverse dimension of the sample increased the correction factor increased from 1 when sample size less than indenter size, to 2.1 when sample size reaches 2.5 times of indenter size. For the sample thickness less than the indenter size, and transverse dimension larger than 2.5 times of the indenter size, a correction factor of 2.1 is suggested to determine the stiffness of the sample based on the force-displacement curve. These findings are independent of the material stiffness, allowing this approach to be generalized to test any soft sample.
Vibration-Based Nondestructive Evaluation of Bio-Printed Constructs Using Phase-Based Motion Estimation
Authors: Taylor Rayanne , Kim Jinki
Published: February 2023

Advances in additive manufacturing technologies have shown that bio-additive manufacturing has opened a new frontier in the biomedical field for 3D printing human organs. Despite these advancements, it is significantly challenging to reliably identify damage features, especially embedded defects, using non-contact methods. This research devises a novel method that can reliably assess the damage characteristics without contact by using video-based vibrometry. Vibration signals provide an integrated response of the target structure including geometry changes such as defects in bioprinting. Since the phase shift of the pixel intensity is intrinsically related to any motion captured in the video, the vibration characteristics that reflect surface and embedded defects can be remotely assessed for the entire structure captured in the camera view from a distance without installing several sensors on the structure. In this study, the vibration characteristics of a cube that is manufactured by an extrusion-based bio-printer with pneumatic dispensing are experimentally obtained by using a high-speed camera and phase-based motion estimation technique. The occurrence of damage and its severity are identified by monitoring the change of the vibration characteristics. A finite element model was formulated, and its response characteristics are compared with the experimentally obtained results. Overall, the results of this study reveal promising potential of implementing video vibrometry for effectively verifying the structural integrity of additively manufactured organs after fabrication, which may be the foundational step in the quality testing of bioprints.
Material Removal Characteristics of Longitudinal Turning of Green Ceramics
Authors: Castellana Jesse , Melkote Shreyes
Published: February 2023

Green ceramic machining involves shaping a dried and extruded part, consisting of a ceramic powder held together by a polymer binder, before it is sintered. This paper investigates the effects of longitudinal turning on the material removal characteristics of green aluminum oxide (alumina) rods, of different binder composition and particle sizes. Forces during machining and the roughness of the machined surfaces are measured and their relationship to the process parameters are analyzed. Results show that low feed, fine alumina particle size, and a positive rake angle tool increased the machining forces. Surfaces were also smoother when the feed was low and the rake angle was positive.
Dynamic Analysis of Low and Medium Maglev Train-Bridge System With Fuzzy PID Control
Authors: Ren Qiao , Zhang Jimin
Published: February 2023

In order to analyze the dynamic behavior of medium and low speed maglev train under different suspension control algorithms and effectively improve the robustness of the suspension control system, an optimized fuzzy PID controller is proposed based on the vehicle bridge coupling model of maglev train. The 23-dof (degree-of-freedom) vehicle model, the modeling of the electromagnetic suspension, and track irregularities are described, respectively. Furthermore, the fuzzy PID controller optimized by the genetic algorithm (GA) is addressed for the control of the dynamic response of the maglev system for complex dynamic conditions. Finally, the proposed controller is applied to the whole vehicle multipoint suspension platform for maglev train to verify the suspension performances in different operation conditions, including static and dynamic conditions. The results demonstrate that the introduction of GA has significantly improved the ride comfort of the maglev moving on the track under different operation conditions.
In-House Built Robust and Adaptable System Architecture for Virtual Reality Haptic Interface
Authors: He An-Chi , Herron Connor W. , Kalita Bhaben , Leonessa Alexander
Published: February 2023

This work presents an in-house built, expandable and flexible system architecture for controlling the robotic motion and supply power to a full-body scale virtual reality (VR) haptic interface named, ForceBot. This VR haptic interface maps the human pilot motion into a virtual avatar, and applies force feedback that results in a high-fidelity sensory of live interaction. ForceBot applies haptic feedback on hands through a pair of pneumatically actuated wearable VR haptic gloves which creates an artificial sense of touch in user’s hands. The robotic arms and the gantry systems are connected to the user’s arms and feet by mounting on a base frame alongside the human pilot. The measured forces are used to synchronize the robot’s motion with the human by allowing a transparent experience during movement and governing desired interaction forces. The whole system architecture consists of mainly three sections: a central computer, a VR computer, and robotic sub-systems. Further, the in-house developed motor control unit ensures the motor behaviour with safety and efficiency for distributing the large amount of electrical power required for the gait simulator to provide support and generate rapid motion. Overall, this system framework can be helpful for the designers and researchers to further study the control and interaction between the robotic motion and the human pilot under VR environments.
An Adaptive Thermal Finite Element Simulation of Direct Energy Deposition With Reinforcement Learning: A Conceptual Framework
Authors: Sousa João , Darabi Roya , Reis Ana , Parente Marco , Reis Luís Paulo , de Sa Jose Cesar
Published: February 2023

During the last decades, metal additive manufacturing (AM) technology has transitioned from rapid prototyping application to industrial adoption owing to its flexibility in product design, tooling, and process planning. Thus, understanding the behavior, interaction, and influence of the involved processing parameters on the overall AM production system in order to obtain high-quality parts and stabilized manufacturing process is crucial. Despite many advantages of the AM technologies, difficulties arise due to modelling the complex nature of the process-structure-property relations, which prevents its wide utilization in various industrial sectors. It is known that many of the most important defects in direct energy deposition (DED) are associated with the volume and timescales of the evolving melt pool. Thus, the development of methodologies for monitoring, and controlling the melt pool is critical. In this study, an adaptive numerical transient solution is developed, which is fed from the set of experiments for single-track scanning of super-alloy Inconel 625 on the hot-tempered steel type 42CrMo4. An established exponential formula based on the response surface methodology (RSM) that quantifies the influence of process parameters and geometries of deposited layers from experiments are considered to activate the volume fraction of passive elements in the finite element discretization. By resorting to the FORTRAN language framework capabilities, commercial finite element method software ABAQUS has been steered in order to control unfavorable defects induced by localized rapid heating and cooling, and unstable volume of the melt pool. A thermodynamic consistent phase-field model is coupled with a transient thermal simulation to track the material history. A Lagrangian description for the spatial and time discretization is used. The goal is to present a closed-loop approach to track the melt pool morphology and temperature to a reference deposition volume profile which is established based on deep reinforcement learning (RL) architecture aiming to avoid instabilities, defects and anomalies by controlling the laser power density adaptability. Despite the small number of iterations during RL model training, the agent was able to learn the desired behaviour and two different reward functions were evaluated. This approach allows us to show the possibility of using RL with openAI Gym for process control and its interconnection with ABAQUS framework to train a model first in a simulation environment, and thus take advantage of RL capabilities without creating waste or machine time in real-world.
Experimental Investigation of Fixed-Geometry Thrust Bearing Taper Geometry on Critical Operating Parameters
Authors: Fais Collier , Yasko Isaiah , Lutfullaeva Anbara , Ali Muhammad , Walker Rick
Published: February 2023

This research presents a newly developed hydrodynamic test rig for experimental testing of hydrodynamic thrust bearings. In this study, the test rig applies thrust loads up to 500 lbf at rotational speeds up to 6,000 rpm. Three fixed geometry hydrodynamic thrust bearings with eight identical helically tapered thrust pads made of cast aluminum alloy have each been machined such that the depth of their tapered surface at the leading edge is 0.0005″, 0.0015″, and 0.0025″ with all other geometrical features held constant. The test rig includes an oil conditioning system which supplies a constant flow of ISO 32 motor oil to the test bearing at 40°C. An integrated sensor system includes an eddy current sensor to measure the minimum oil film thickness, a friction torque moment arm with load cell to measure power loss, K-type thermocouples to measure bearing temperature, pressure transducers to measure oil film pressure distribution, and load cells to measure the applied thrust force. The test rig also introduces a novel bearing alignment system used to ensure precise alignment of the bearing and runner during operation based on pressure feedback from individual thrust pads. Results obtained from this experiment are used to compare the effect of taper geometry on active performance of the test bearings considered. Trends in performance observed are related to the trends predicted analytically by the Reynolds equation.
Transmission Characteristics of Pulsatile Parameters in an Initially-Tensioned Orthotropic Artery
Authors: Hao Zhili
Published: February 2023

With radial and axial displacement of the arterial wall being considered, the problem on the pulse wave propagation in an initially-tensioned orthotropic artery is formulated and solved by using a free wave propagation approach, identifying the Young wave and the Lamb wave in an artery. With pulsatile pressure in blood flow and axial stress in the arterial wall as the sole excitation source for the Young wave and the Lamb wave, respectively, transmission characteristics of the two waves are theoretically analyzed and the influence of wave reflection and harmonics on the waveforms of various pulse parameters is identified. Numerical values for transmission characteristics of the two waves at the ascending aorta (AA) and the carotid artery (CA) are calculated. Regardless of the relative excitation source amplitudes in the two waves, pulsatile pressure, radial displacement, circumferential stress, and blood flow rate are found to be solely in the Young wave. In contrast, the relative excitation source amplitudes of the two waves determine which wave is dominant in axial displacement, axial stress, and wall shear stress. This work sheds new insights on the wave propagation behavior in arteries and might improve the interpretation of measured pulsatile parameters for arterial health assessment.
Numerical Analysis of Interfacial Electrohydrodynamic Flow With Modal Decomposition
Authors: Cândido Sílvio , Páscoa José C.
Published: February 2023

For many applications, Reduced Order Models (ROMs) use linear tools such as Proper Orthogonal Decomposition (POD) as a method for analysing the spatio-temporal coherence of dynamical systems and to construct reduced order models of fluid flows and optimally balanced control laws and identify correlations between different flow quantities. In particular, these techniques are of interest for liquid injection systems due to the inherent complexity of multiphase interactions, and extracting the underlying flow processes is desirable. In this study, we propose to use these techniques to determine a ROM for electrohydrodynamic interfacial flows, more specifically for a Taylor cone jet. From engineering nanofibres to propulsion, the electrohydrodynamic jets bring us an outstanding technique for the emission of microdroplets. This is due to the stretching of interfacial flows due to the external application of an electric field. The present investigation uses an efficient geometric Volume-Of-Fluid (VOF) method, called isoAdvector, to compute the advection equation of the phase fraction. This algorithm computes an immiscible two-phase flow, that is then coupled with the reduced form of the Maxwell equations for an electrostatic field and a transport equation for the electric charges. Electrically induced body forces are incorporated into the hydrodynamic momentum equation with the Maxwell Stress Tensor (MST). A laminar condition is assumed for the flow, thus the laminar incompressible Navier-Stokes’s equations are used to compute the hydrodynamic behaviour of the flow and the associated The modal decomposition POD uses the snapshot technique with a set of high-definition snapshots of the transient behaviour of the jet. The dynamic structures, formed by the velocity field and the electric charge dynamics, determine the fundamental dynamics of the droplet emission. The results show that 2D POD based ROM models can accurately reconstruct the flow field details, properly identifying the flow characteristics. The axial velocity transports the jet almost in a steady regime since a low number of POD modes are needed to preserve 99% of the kinetic energy. The flow fluctuations, principally the breakup of the jet, are represented by the fluctuations of the electric charge density, which is transported by the velocity field and the external electric field.
Electrostatically Actuated MEMS Cantilevers of Linear Thickness Variation: Amplitude-Frequency Response of Parametric Resonance
Authors: Caruntu Dumitru , Flores Rigoberto
Published: February 2023

This paper deals with the frequency-amplitude response of parametric resonance of alternating current (AC) electrostatically actuated nonuniform micro-electromechanical system (MEMS) cantilever resonators. The resonators consist of a cantilever of linear thickness and constant width, parallel to a ground plate, and under AC voltage producing soft excitations. AC frequency is near first natural frequency of the cantilever. The fringe effect is included in the electrostatic force. Two reduced-order models (ROMs), namely ROMs using one and two modes of vibration, are developed. Two methods are used to solve these ROMs: the method of multiple scales (MMS), and numerical integration. The frequency-amplitude response shows a softening effect and two bifurcation points, one subcritical and another one supercritical. The two bifurcation points occur at zero amplitude. Three branches of steady-state solutions are predicted, one zero amplitude branch, and two non-zero amplitude branches, one stable and one unstable. Pull-in occurs for constant frequency with initial amplitudes above the unstable branches, or when the frequency is swept down from frequencies larger than supercritical bifurcation frequency. The range of frequencies between the bifurcation points decreases as damping increases and/or voltage and fringe effect decrease. Between the two bifurcation points, damping, voltage, and fringe effect have the greatest effect on the subcritical bifurcation point.
The Effect of Buoyancy-Driven Convection in Vacuum Membrane Distillation Module
Authors: Caspar Justin , Xue Guanyang , Asiri Jaber , Oztekin Alparslan
Published: February 2023

CFD simulations were run to determine the impact of buoyancy-driven natural convection on Membrane Distillation, a thermally driven filtration process. A computational domain was created with a high Grashoff number, and vertical and horizontal modules were considered. Convection cells were dominant in the channel at low Reynolds numbers and effectively increased the performance of Membrane Distillation modules by up to 66%. This was done by generating convection cells that reduced the temperature/concentration polarization inside that module, typically forming due to the low Reynolds numbers and correspondingly high thermal and concentration boundary layers. It is shown here that natural convection enhances the flux performance of membrane distillation immensely.
Effects of Surface Finish and Molecular Structure on the Lubricating Ability of Borate-Based Protic Ionic Liquids
Authors: Sierra Alfonso , Scott Hope , Pray Darwin , Polus Zachary , Iglesias Patricia
Published: February 2023

Friction and wear are inherent problems in mechanical systems, leading to about 23% world’s total energy usage. However, energy losses could be reduced by up to 40% using high-performance lubricants.

In order to meet these objectives, Ionic liquids have been studied for more than two decades. Ionic liquids are a class of synthetic salts with melting points below 100 °C due to their asymmetric chemical structure. This feature confers them remarkably interesting physicochemical properties. Moreover, the delocalized charge in their functional groups enables them to react with metal surfaces through the formation of protective layers that prevent them against contact. Ionic liquids are generally categorized based on the nature of their cation into aprotic ionic liquids and protic ionic liquids. Even though aprotic ionic liquids have been proved as neat lubricants and additives with great performance, their applicability is limited as a consequence of the complexity of their synthesis. On the contrary, protic ionic liquids can be easily obtained through proton transfer from a Brønsted acid to a Brønsted base.

In this study, two borate-based PILs, N-methylethanolamine 1,2-dodecanediolborate and N’N-dimethylethanolamine 1,2-dodecanediolborate, were synthesized, with same anion and different ammonium cation. Their lubricating abilities were investigated as neat lubricants on steel-steel contact at room temperature, using a custom-designed ball-on-flat reciprocating tribometer. Each protic ionic liquid was tested using ground and polished steel disks and two levels of normal force and frequency.

Results showed that the surface finish have an important influence on the lubricating performance of these ordered fluids. In addition, frequency was found to have an influence on the wear mechanisms on steel surfaces.
Senior Capstone Design Research Project: Study of the Combustion of Paraffin-Based Fuels in Hybrid Propellant Rocket Engine
Authors: Naoumov Viatcheslav , Al-Masoud Nidal , Mahjoob Mohammad
Published: February 2023

Paraffin-based fuels such as paraffin, beeswax, and others are considered as an advanced fuels for Hybrid Propellant Rocket Engine (HPRE). Starting from 2010, engineering faculty/student teams were performing long-term experimental study of the combustion of pure paraffin-based fuels and paraffin-based fuels enriched by aluminum powder in the frameworks of engineering senior capstone design projects and faculty/student research. Test fixture, consisted of unique lab-scale HPRE, oxygen supply system, propane supply system, flow control systems, ignition system, instrumentation system and data acquisition system were designed and built. More than 130 experiments were performed aimed to study the combustion of bio-derived fuels. Dozens of regression rate formulas were obtained which are essential for the prediction and analysis of combustion parameters and calculation of HPRE thrust and specific impulse. Student-faculty teams discovered experimentally and simulated theoretically a considerable loss of unburned paraffin-based fuels and estimated the influence of these losses on the regression rates. Performing this multidisciplinary challenging project student teams faced with a variety of problems and successfully resolved them. HPRE project provided mechanical engineering students with excellent opportunity to apply their knowledge, skills, and experience from a variety of courses to the real-life design and research.
Automation of a Dual Planetary Gearing Transmission Using Control Mechanisms and a Programmable Logic Controller
Authors: Fadow Olivia , Leonard Skyler , Azzouz Salim
Published: February 2023

The transmission used in this project has been worked on by three senior design teams. The fourth team is currently working to design control mechanisms to automate the manual dual planetary transmission. The control mechanisms are a combination of mechanical and pneumatic systems that are controlled by a Programmable Logic Controller (PLC) program. The transmission will be used in the Machine Elements Design Laboratory to educate students on gear transmissions and levers. SolidWorks software was used to draw and simulate the mechanical parts of the control systems, before being sent to a machine shop for manufacturing. The first control system uses vertical levers and linear actuators to control the brakes, while the second uses horizontal levers and rodless pneumatic cylinders to control the clutches. Willis Gearing Theory was then used to determine the six gear ratios realized by the transmission. To automate the mechanical parts of the control systems, a program was designed and uploaded to the CPU console. A Human Machine Interface (HMI) displays the transmission’s speed and torque readings from the PLC. It is expected that the future group will the finish the automation of the transmission and proceed with the testing phase.
Assessing the Potential for Implementation of Distributed Ledger Technology in the Nuclear Power Plant Lifecycle
Authors: Pandit Priyanka , Nevius Daniel , Srivaths Vibhav , Diaconeasa Mihai A.
Published: February 2023

The Nuclear Power Plant (NPP) project lifecycle consists of multiple organizations, private and public, that work together to carry out the licensing and regulation, commissioning, construction, supply chain management, decommissioning, and non-proliferation of nuclear power plants. Each stage of the lifecycle generates a considerable amount of documentation that needs to be archived and made available on request. In this paper, we examined the current frameworks employed by the stakeholders of nuclear power plant lifecycles for data generation, classification, archival, and exchange and we evaluated the use of distributed ledger technology for data management. We further demonstrated the implementation of distributed ledger technology to capturing and immutable recording nuclear supply chain structure, production, and failure data.

Distributed Ledger Technology (DLT) promises to address the current bottlenecks in the lifecycle management of nuclear power plants with faster data exchange times, lower processing cost of documents, bridging the gap between perceived and actual risk, faster decisions, customizable transparency in job tasks being executed, improved cash flow, instant validation of job completion, reduction in logistical friction, and sped up supply chain decisions for clients. We gave a comprehensive review of distributed ledger technology, its properties and an open-source permissioned distributed ledger system called Hyperledger Fabric.

Each sector of the nuclear power plant lifecycle was analyzed for data management bottlenecks and building on our discussion of employing distributed ledger technology we discussed the pathway in which Hyperledger Fabric can be employed to address the data management bottlenecks in each stage of the lifecycle including, licensing and regulation, commissioning, construction, supply chain management, decommissioning, and non-proliferation.