bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis and Assessment of the Spring-Back Effect of Steel Sheet Metal Under Bending Operations
Authors: Pérez Martínez Omar , Medellín-Castillo Hugo I.
Published: January 2020

The accurate prediction of the spring-back effect is a major issue in the design of metal forming tools and operations. A bad prediction of the spring-back effect will cause geometrical and quality deviations from the designed part, together with the associated cost impacts. In this paper the analysis and evaluation of the spring-back effect of steel sheet metal under bending operations is presented. The aim of the work is twofold: 1) to assess how accurate the spring-back effect can be predicted by the finite element method (FEM) and theoretical approaches, and 2) to evaluate the effect of process parameters on the springback effect. To accomplish this, two case studies corresponding to L-bending and V-bending operations of steel sheet metal were selected. The spring-back effect for these case studies was then analysed and estimated using theoretical approaches and FEM. Several values of the process parameters were also considered in the evaluation. Finally, the results were compared with the experimental values and the prediction error for each approach was estimated. The results have suggested that the FEM approach can predict with accuracy the spring-back effect; however, the solution is very sensitive to the simulation and process parameters.
Enhancing the Performance of Centrifugal Pump by Adding Cylindrical Disks at Inlet Suction
Authors: Sadik Linda , Jawad Badih , Hermez Munther Y. , Liu Liping
Published: January 2020

Optimizing the high efficiency design of centrifugal pumps requires a detailed understanding of the internal flow. The prediction of the flow inside the pump can be acquired by understanding the rotatory motion and the three-dimensional shape of the impellers, as well as its fundamental unsteady behavior. The flow inside a centrifugal pump is three-dimensional, unsettled and always associated with secondary flow structures. When a centrifugal pump operates under low flow rates, a secondary flow, known as recirculation, starts to begin. Inside this, the separation of flow increases, which creates vortices and cause local pressure to decrease, which induces cavitation. This phenomenon of recirculation will increase the Net Positive Suction Head Required (NPSHR).

Improving the suction performance continues to remain a vital and continuous topic in the development and application of centrifugal pumps. In this research, the focal point is to enhance the pump suction performance under low flow rates by modifying the impeller design. This research entails a numerical simulation investigation on the addition of three different designs, each consisting of two cylindrical disks at the impeller inlet suction. It is hypothesized that these modifications will assist suppressing the recirculation phenomenon. The turbulent flow within the centrifugal pump was analyzed by applying the Reynolds-Averaged Navier-Stokes equations and the k–ϵ equations for turbulence modelling. The computational domain consists of the inlet, impeller, diffuser and outlet. Analysis of ΔP, torque data and pump efficiency was conducted. The application of CFD solvers to predict pump performance resulted in reduced prices for testing as well as pump development time.

The numerical simulation concluded that placing 3-D multi-cylindrical disks at the impeller inlet section improved the centrifugal pump performance under low flow rates. The model design 1 resulted in a pump efficiency improvement of about 5% at low flow rates by lowering the amount of flow leaking back (re-circulation) through the internal suction.
Opportunities for Radiation Pressure in Characterization of Micro- / Nano-Materials
Authors: Leseman Zayd C.
Published: January 2020

Manmade use of radiation pressure in optomechanical devices is a relatively new concept and warrants a discussion of its possibilities. In this article, the limitations and opportunities of radiation pressure’s use in optomechanical devices will be examined from the perspective of mechanical testing of materials. Concepts and physics not normally considered in mechanics of materials are introduced in order to inform the greater materials characterization community of the unique possibilities that optomechanical devices offer. In particular, it is shown that forces in the range of fN – μN can be traceably calibrated using radiation pressure.
Numerical Analysis With Physical Test Correlation and Design Optimization of a Rollover Protective Structure (ROPS)
Authors: Karpat Fatih , Yahşi Mehmet , Akalp M. Kaan
Published: January 2020

In this study, a rollover protective structure design was investigated according to its performance required for product validation. An investigation was performed by using finite element method and the acceptance criteria was taken from the OECD Code 6 standard. After performing finite element analyses in order to simulate ROPS loadings, it was found that the strength of the current ROPS design is good enough and this situation was correlated with physical tests. This situation allows to make some weight reduction studies. Firstly, an analytical optimization study performed on current ROPS design. A new ROPS design was achieved and this design was called as “Design 1”. After that, a parametric optimization study was built and newly achieved ROPS design was called as “Design - 2”. These optimization studies gave some design suggestions but the all changes in studies was not applied to new ROPS design because of some design constraints. The simulation results correlated with tests for the final design also. This study provides an effective method for virtual validation and design optimization of a rollover protective structures.
Axiomatic Design to Foster Additive Manufacturing-Specific Design Knowledge
Authors: Chekurov Sergei , Niklas Kretzschmar , Rossoni Marco , Redaelli Davide F. , Colombo Giorgio
Published: January 2020

Axiomatic design has the potential to help designers understand the increased design freedom and limitations of additive manufacturing prior to starting the actual design process. The purpose of this study is to verify the usefulness of Axiomatic Design in the design process of complex additively manufactured components. The article uses a case study involving the design of a non-assembly turbine to demonstrate that Axiomatic Design can be applied as a supportive tool to acquire information on new limitations imposed by additive manufacturing, such as minimum wall thickness and maximum size of parts. The use of axiomatic design is demonstrated by describing the process of decomposition of the non-assembly turbine and examining the suitability of the general design according to the independence axiom. The resulting decomposition chart is subsequently used as a basis by the authors to design individually two competing designs of a turbine. Finally, the information axiom is used to determine the design with the lowest information content according to design (part and support volume), performance (pressure drop) and economic parameters (cost).
Periodic Motions With Grazing in a Discontinuous Dynamical System With Two Circular Boundaries
Authors: Guo Siyu , Luo Albert C. J.
Published: January 2020

In this paper, studied are periodic motions with grazing in a discontinuous dynamical system with two circular boundaries. The grazing motion is for a periodic motion switching to another periodic motions. Thus, the sufficient and necessary conditions of motion switching, grazing and sliding on the boundaries are discussed first. Periodic motions with grazing in the discontinuous system are presented for illustration of motions switching.
Jet Initiation After Drop Impact on Micropatterned Hydrophilic Surfaces
Authors: Siddique Anayet Ullah , Zhao Feng , Weislogel Mark , Tan Hua
Published: January 2020

Droplet-wall impacts are well known to produce a wide variety of outcomes such as spreading, splashing, jetting, receding, and rebounding from hydrophobic and superhydrophobic surfaces. In this work, we focus on the growth of jets that form during the partial recoil of liquid droplets that impinge upon hydrophilic substrates composed of cylindrical micro-pillars of various dimensions and distributions (i.e., height, width, pillar spacing, etc.). Micro-pillars are fabricated on the hydrophilic silicon wafers by standard microfabrication processes, including metal etch mask patterning by photolithography, metal deposition, and lift-off to achieve the designed pillar shapes and spacing, and followed by dry etching for various pillar heights. Micrometer-sized drops of glycerol mixtures impacting micro-structured wafers are investigated using high-speed video photography. Impact velocities are varied to observe the influence of Weber number on the dynamic properties of the rebounding jet and jet initiation time, as well as whether or not the jet detaches ejecting satellite droplets normal to the substrate surface. The specific influence of the micro-patterned surfaces on maximum spreading, jet formation, jet tip velocity, and jet ejection is characterized. We find that the micro-patterned substrates have a significant effect on the behavior of the drop impact and jetting mechanism. From our experiments, we find that jet velocity is approximately 4 times that of the drop impact velocity. The jet formation time is shown to follow the capillary time scale as (ρDi3/σ)½ (where ρ, Di, and σ are density, initial droplet diameter, and surface tension, respectively).
Three Dimensional Dynamic Model Development and Validation for Stranded Cables
Authors: Jalali Mohammad Hadi , McKercher Richard , Rideout Geoff
Published: January 2020

Interactions between cables and structures affect the design and non-destructive testing of electricity transmission lines, guyed towers, and bridges. In order to understand the effect of conductors on dynamics of utility poles, a three dimensional dynamic model for stranded cables is presented based on the bond graph formalism and validated through experimentation. The cable is modeled considering the bending stiffness, tension and sag due to self-weight. The model consists of three-dimensional rigid segments, connected with translational and rotational springs and dampers. To validate the model, an instrumented set up for a stranded cable was tested in the laboratory and the model was validated in both the in-plane and out-of-plane directions in the frequency domain by measuring the cable response to hammer impacts in both directions. Time domain response obtained from simulation was also validated with experimental time response by performing a free vibration test. A set up was designed and built to accurately measure the bending stiffness of a stranded cable in different tensions and the measured values for bending stiffness were used in the numerical model. It was observed that the bending stiffness increased with the increase in tension. The modal properties of the cable were obtained numerically and experimentally for different tensions and consequently for different amounts of sag. The model is verified to have sufficient fidelity to predict the dynamics of cables undergoing both in-plane and out-of-plane motion, and can be used in a pole-cable system model to investigate the effect of cable on dynamics on poles or structures.
A Multi-Stage Optimization Approach for Energy Supply Systems With Discrete Design Decisions
Authors: Bruche S. , Tsatsaronis G.
Published: January 2020

Mixed integer linear programming is frequently applied to identify promising design solutions of energy supply systems. However, application-relevant optimization models are often associated with complicating model features, e.g. numerous discrete design candidates or a large time horizon of the optimization. So, even state-of-the-art solvers may be confronted with major challenges to find satisfying solutions within reasonable time. In this paper a systematic multi-stage optimization approach is proposed that is intended to support the available algorithms in solving these complex problems. The basic idea of the approach is the distribution of the original problem into two major levels. On the first level, promising design candidates are generated using simplified optimization models. These simplifications are achieved through time series aggregation and the relaxation of operational binary variables. In the second stage, the objective values of the design candidates for the original problem are determined. The division of the problem into two stages leads to a significant reduction in required optimization time but simultaneously leads to an uncertainty regarding the quality of the found solution. Therefore, in a subsequent step, it is checked whether the objective value is within an acceptable distance from the theoretically best solution. If this is not the case, the first two steps are iteratively repeated. The proposed multi-stage approach is applied to the optimization of an energy supply system located in Germany. The results show a superior performance regarding required optimization time over conventional methods.
On Dimension Synthesis of Hart’s Inversor III Straight-Line Mechanism As a Precision Robotic End-of-Arm Tool
Authors: Huang Ming Z.
Published: January 2020

In flexible manufacturing systems, straight line motions are often required in part handling, assembly, cutting, sealing, or welding operations. Rather than using a high performance industrial robot to execute the path directly, employment of a less precise robot outfitted with an end-of-arm tool comprising an exact straight line mechanism could be more effective in both performance and in cost. Exact straight line mechanisms with pin connections are easy to manufacture and assemble, in comparison to those realized by translational joints where alignment of linear axes or surface could be problematic. Such an issue becomes even more difficult when relatively large stroke and/or high precision of straight line motion is required. In this paper, a study of the kinematic characteristics of a special class of exact straight line mechanisms, Hart’s Inversor Type III, with emphasis toward dimension synthesis, is presented. An analytical approach for sizing the link lengths with respect to a desirable straight line stroke constraint is developed and illustrated with examples. Also presented are stiffness and mechanical advantage characteristics for additional design considerations.
A Systematic Material Design Approach to Develop Self-Lubricating Ceramic-Composite Tool Inserts for Dry Cutting Conditions
Authors: Akhtar Syed Sohail
Published: January 2020

A systematic approach is the focus of the current work in order to design and develop ceramic composites for cutting tool inserts with a balanced combination of structural and thermal properties together with enhanced antifriction characteristics. In the material design stage, various combinations of ceramic materials and inclusions with optimum self-lubricating attributes are selected based on predictions of mechanical and thermal properties using in-house built codes. A mean-field homogenization scheme is used to predict the constitutive behavior while J-integral based fracture toughness model is used to predict the effective fracture toughness of the ceramic composites. An effective medium approximation is used to predict the potential optimum thermal properties. The current strategy incorporates thermal and structural properties of composites as a constraint on the design process together with self-lubrication property. Among various metallic and carbon-based fillers, silicon carbide (SiC) together with titanium oxide (TiO2) and graphite are found the most suitable candidate fillers in alumina (Al2O3) matrix to produce cutting inserts with best combinations of thermal, structural and tribological properties. As a validation, various combinations of Al2O3-SiC-TiO2 and Al2O3-SiC-TiO2 composites are developed in line with the designed range of filler size and volume fraction using Spark Plasma Sintering (SPS) process to complement the material design.
A Methodology for Virtual Factory Applications Definition, Development and Validation
Authors: Marcelino-Jesus Elsa , Sarraipa Joao , Fraile Francisco , Poler Raul
Published: January 2020

The Virtual Factory Open Operating System (vf-OS) aims to become the reference system software for managing factory related computer hardware and software resources and providing common services for factory computational programs. Additionally, it provides a methodology to support the implementation of virtual factory applications to be deployed in industrial scenarios. This paper focuses on this proposed methodology that guides the virtual factory applications definition, development, and validation. It takes into account the industrial application requirements and specifications to technically and business validate its integration in the proposed vf-OS environment and in the real factory production. Thus, this methodology presents the successive steps and interactions that occur in the process, during the following proposed three phases. In the starting phase, the functionality of the application taking into consideration the actors involved in the process e.g. manufacturing and logistics users and software developers is defined. The development and test phase represent the moment in which the applications are developed, deployed and tested inside pilots’ premises. The evaluation phase is when applications are validated by the evaluators to guarantee that they fulfil the needs of the users. In line with these phases, the methodology presents templates and guidelines that both developers and users should fill to create a common understanding of what is desired. This includes a use case definition template, an application questionnaire, and guidelines for the creation of sketches, mock-ups, and workflow diagrams. This paper demonstrates the proposed methodology reporting the evaluation conducted in three different industrial pilots: 1) manufacturing and logistics or automation: applications focused on providing support to maintenance and spare part stock management in automation production equipment; 2) construction or industrialization: applications to improve time and resource utilization in construction projects through advanced collaboration between construction managers and material providers; 3) manufacturing assembly or collaboration: applications to enable collaborative design and manufacturing of complex products.
Secondary Flows in Eccentric-Annular Tubes
Authors: Letelier Mario , Siginer Dennis A. , Almendra Diego L. , Stockle Juan
Published: January 2020

In this paper, transversal flow field of nonlinear viscoelastic fluids abiding by the modified-Phan-Thien-Tanner (MPTT) constitutive model in straight tubes of eccentric-annular cross-section is investigated. An analytical solution is developed based on an asymptotic expansion in terms of the Weissenberg number coupled with the shape factor method a one-to-one mapping taking the circular cross-section into the eccentric annular cross section. The analysis reveals the formation of transversal flows due to elasticity and to the eccentricity parameter. The number of vortices in the cross-section depends on the ratio of the diameters in addition to the eccentricity parameter. The effect of these parameters on the vortical structure is explored for different values of the material parameters.
Mesh-Less Analysis of Products: A Revolution Within Computer Based Design Analysis
Authors: Petersson Håkan
Published: January 2020

For many years, FEA (finite element analysis) has been the dominant way of evaluating the mechanical properties of products. Engineers and design analysts are well familiar with the technology, and it is used for a lot of different types of phenomena. It is not easy to use FEA as it requires a lot of knowledge and skills for the analysis to be successful. One of the many problems is that it quickly becomes a large model with a large number of equations that have to be solved. A computer with a large internal memory, a fast CPU and fast hard disk drives is expensive to purchase and to keep up to date.

Another problem is when thin-walled solids have to be analyzed. You usually need 2–3 elements in thickness to be able to obtain all stresses, which requires a lot of elements and nodes and makes the computations large or even too large. To solve these types of problem, a conversion to surfaces has to be made, where 2D shell elements may be used. Converting solids to surfaces can be demanding and time-consuming. It is a compromise, but it is solvable as a 2D model. As we all know, all body-in-white, e.g., automotive and aerospace industry, is analyzed by this method.

A new type of software has recently reached the market, mesh-less design analysis, which makes it possible to perform design analysis in all kind of solids, very quickly and by using much less solving time and computer power. As this type of software doesn’t mesh the geometry, much time can be saved both on the geometry but also on waiting time for the problem to be solved. The main question is, “is it too good to be true”?

In this paper, the focus is on comparing two types of design analysis software, traditional FEA, and mesh-less design analysis. Different samples of design problems have been analyzed and compared; results and conclusions are reported.
New Control Valve Technology Requiring Engineering Solutions to Reduce Erosion Corrosion and Flow Accelerated Corrosion
Authors: LeBoeuf Catherine , Laurito Mark
Published: January 2020

Due to the new control valve technology presented in this paper, inlet and outlet reducers must be used to replace globe valves up to five times its size in existing systems. In many water, steam or any high velocity fluid application, there are wear mechanisms, such as Erosion Corrosion (EC) and Flow Accelerated Corrosion (FAC), that cause wall-thinning and pitting in process equipment. This deterioration of the reducer wall can be extremely dangerous and, ultimately, can cause reducers to fail.

In an attempt to lessen the risk of these failure modes, using Computational Fluid Dynamics (CFD), Clarke Valve™ has engineered new asymmetric reducers that are cast into the body of the valve. These newly designed reducers with a coned-shaped inlet and a bell-shaped outlet will decrease failures in the field by reducing high velocity areas along the pipe wall, preventing unplanned downtime and unsafe system failures.

A digital twin of both the off-the-shelf (OTS) reducers and the newly designed asymmetric reducers were created and, in support of the design process, CFD simulations were used to not only observe the deficiencies in the existing “off-the-shelf” (OTS) reducers, but also optimize the newly integrated asymmetric reducers.
Numerical Investigation on Thermal and Fluid Dynamic Behaviors of a Thermoelectric Generator in an Exhaust Automotive Line With Aluminium Foam
Authors: Buonomo Bernardo , di Pasqua Anna , Ercole Davide , Manca Oronzio , Nardini Sergio
Published: January 2020

In the present work a two-dimensional steady state convective heat transfer problem in a channel aluminum foam partially filled with an external thermos-electrical generator (TEG) component is numerically solved. The channel is characterized by a length equal to 272 mm and by a height of 60mm; instead, the TEG has a length equal to 65 mm and a thickness of 8.5 mm. The metal foam is modelled assuming the local thermal equilibrium (LTE) hypothesis. The TEG is analyzed as a solid with an internal energy generation. Thermophysical properties of the exhaust gas are assumed equal to the ones of the air. The governing equations are considered with temperature independent thermophysical properties. The governing equations for gas, porous media and TEG are solved by finite volume method using the Ansys-Fluent code. The foam is characterized by a porosity of 0.92 and number of pores per inch equal to 5, 20, 40. Results are carried out for several mass flow rates of gas and different thicknesses of metal foam. Results are given in terms of temperature distributions, pressure drop, thermoelectric efficiency and power density for TEG for different exhaust gas flow rates and aluminum foam thicknesses.
Definition of Basic Functional Geometries: A Survey to Support Automatic Metrology
Authors: Vale André Pinto , Silva João , Costa Carlos A. P. , Machado Michael
Published: January 2020

The greed of consumers always increasing in terms of performance, quality and price of future products, has contributed a lot in recent decades to the development of integrated manufacturing systems and the production of large series. At the same time, measuring processes and systems have become increasingly flexible and capable of automatically verifying the conformity of the products at the inspection stage. The article intends to approach the fundamental concepts and techniques used in the evaluation of the basic functional geometries: plane and cylinder. The paper will present an overview of the main inspection methods and the mathematical foundations used to contribute to the automatic measurement of a fundamental geometry (cylindric).
Combustion of Biomass Based Pellets With Pyrolysis Bio-Oils
Authors: Couto Diogo Manuel , Gonçalves Maria Margarida , Carvalho Joana , Ferreira Manuel Eduardo , Araújo Jorge , Teixeira José Carlos , Vilarinho Cândida
Published: January 2020

Due to increased energy demands and environmental concerns, biomass has become an increasingly attractive primary source in the energy mix. It can be used as heat supply to both domestic and industrial sectors, but also as fuel in dedicated or co-generation-based power plants and it is also considered CO2 neutral.

Amongst the most widely used formats, wood pellets are very attractive because of their standardized properties which makes them efficient over a wide range of applications. In Portugal alone, over 1 million tons a year are produced. However, due to their attractiveness, the pressure on traditional raw materials for their fabrication (saw dust) has driven the cost upwards and induced bottlenecks upstream in the supply chain. One way to expand the range of raw materials is to combine a biomass based matrix with alien materials into the same pellet format. In this way one can also find alternative uses for other materials which, some of them wastes, are often dumped into landfills. Such an approach has been pursued into combining industrial wastes with biomass in pellets.

This project concerns the evaluation of the combustion behavior of saw dust based pellets fortified with pyrolysis bio-oils produced from waste vegetable oils. The bio-oil is an organic liquid obtained by pyrolysis of used vegetable sunflower oil, at 420 °C and 10 min. The pellets were manufactured with pine saw dust with bio-oil incorporation up to 5% in mass. The resulting pellets were fully characterized for their properties, including the heating value, which increased when compared with standard saw dust pellets. These pellets were afterward tested in a fully instrumented 20 kW fixed grate combustion facility. The flue gases were analyzed and the resulting ashes were tested for their chemical composition in order to assess their ability to melt during combustion. The results show that this route can be beneficial in terms of exhaust emissions, including promoting the reduction of NOx during combustion. However, the physical characteristics of the pellets have some restrictions, since they do not meet minimum requirements for its certification ENplus level of density, mechanical durability and fines content.
Effect of Annealing on the Microstructure and Mechanical Properties of Mg-9Al% Alloy Plates Processed With Symmetrical and Asymmetrical Rolling
Authors: Xu Zhigang , Zhang Honglin , Yarmolenko Sergey , Wei Qiuming , Kecskes Laszlo , Sankar Jagannathan
Published: January 2020

In this study, the Mg-9Al% plates with a total of approximately 50% thickness reduction corresponding to 0.76mm per pass, were obtained by symmetrical and asymmetrical rolling. The effect of different annealing temperature and corresponding holding time on the microstructure and mechanical properties were investigated. Key results showed that in the as-rolled state, the plates processed by asymmetrical rolling had smaller grain size and higher hardness value and ultimate tensile strength than symmetrical rolling. After annealing treatment, the hardness value of the both plates decreased due to the internal stress released. A good combination of strength and ductility were achieved for symmetrical and asymmetrical processed plates at 350°C for 1 hour and 325°C for 1 hour, respectively, which can be attributed to the static recrystallization and weakening the basal texture. These results show that the appropriate annealing is an effective way to enhance the mechanical formability of plastic deformed Mg plates.
Study of Low-Frequency Narrow Bandwidth Surface Acoustic Wave Sensor for Liquid Applications
Authors: Lee Kun-Lin , Voiculescu Ioana
Published: January 2020

Surface acoustic wave (SAW) devices have been applied as telecommunication filter for decades. Due to its simple interdigitated transducer (IDT) layout and geometry-dependent frequency, the SAW filter operates at the designed frequency and its working bandwidth could be designed to fulfill specific applications. Researchers also use SAW devices for sensing the mass or pressure in air. Furthermore, SAW device can be employed in liquid environments. The main focus of this paper is to present a Love mode device for liquid sensing. The Love mode device included a shear-horizontal surface acoustic wave (SH-SAW) delay-line configuration with a photoresist waveguide, which was deposited on split-electrode IDT and reflectors. The substrate was ST-cut quartz, and the SH-SAW propagated between the waveguide and the piezoelectric substrate. Using the Love mode device, we monitored the frequency shift corresponding to a water drop. We demonstrate that the insertion loss level is not critical for S-parameter transmission signal readout. The signal quality within the resonant narrowband is very important for water sensing. In this study, two types of SH-SAW devices were fabricated and tested; SH-SAW resonator and SH-SAW delay-line. We also demonstrate single and split electrodes electrode configurations to generate acoustic waves. Four different waveguide thickness values were tested to prove the benefit of thick polymer waveguide. This research also offers a standard method to fabricate SAW on ST-quartz for liquid application. In the future, we plan to integrate the Love mode device with a cell-culturing chamber to obtain a biosensor.
Design and Start-Up of a Plant for Dairy Processed Sweets
Authors: Maradey Lázaro Jessica Gissella , Garrido Gianina , Cáceres Kevin
Published: January 2020

The industry of processed dairy and fruit sweets is listed in the agroindustry as one of the most representative at the economic level preceding poultry and oil palm production. In addition, the requirements of safety and product quality that are indispensable, it also requires committed and specialized labor generating a social impact in terms of employability and competitiveness of the companies that make up the production chain.

The production process is carried out in an artisanal way, therefore, one of the problems faced by this industry is the absence of technology and / or automation that allows them to improve process times and, consequently, productivity. However, this can be solved with the incorporation of systems that optimize the acquisition and control of the process variables of cooking and dosing of the sweet, reducing the costs due to waste and poor handling of its ingredients, as well as reaching higher production levels with quality and products that meet the standards imposed by globalized markets.

This article shows the development, implementation and start-up of a pilot plant for the cooking and dosing of the sweet, taking into account that the capacity of the hopper is 70 liters.

The results show a considerable improvement in the quality and process standards, as well as establishing criteria to optimize other variables that appear in the development.
Flow Modelling of Propulsion Nozzles for Nano-Satellites
Authors: Páscoa Marques José , Ribeiro Gustavo , Brójo Francisco
Published: January 2020

The development of compact propulsion systems for nano and micro satellites is nowadays a growing research topic. Actually, the availability of low cost materials able to withstand space operation is now becoming widespread technology. This democratization on the access to space was not followed with a corresponding availability of critical propulsion technologies. However, the availability of propulsion systems for this class of satellites will provide them with new possibilities in what relates to mission profiles. In the present work an electrospray will be analysed, in particular the flow in the nozzle. This flow is controlled by a mix of pressure and electrostatic field. A full EHD (electrohydrodynamics) computational model is developed that is integrated in a classic CFD code using user specified functions. The proposed computational model was able to compute the flowfield for the electrospray test case under consideration. A benchmark against experimental results, by comparing spray thruster droplet size, concluded that the numerical model can predict their size within an error of 5%.
EMG Controlled Soft Robotic Bicep Augmentation
Authors: Zhang Jiayue , Vanderbilt Daniel , Fitz Ethan , Dong Janet
Published: January 2020

Repeated lifting tasks are often required of industrial workers. Such repetitive loading of workers’ arms throughout the workday can lead to injury and fatigue. This paper details the development and prototyping of a wearable soft robotic device to augment a worker’s arms by sensing and mimicking the contractions of their arm muscles. The device shares lifting loads with the user’s muscles to increase their lifting capacity, thereby preventing injury and reducing fatigue. The human arm contains many muscles that coordinate to produce movement. However, as a simplified proof of concept, this project developed a prototype to augment just the biceps brachii muscle since it is the primary pulling muscle used in lifting movements. Key components of the prototype include a soft robotic actuator analogous to the biceps, a control system for the actuator, and a method of attaching the actuator to the user’s arm. The McKibben-inspired pneumatic muscle was chosen as the soft actuator of the prototype. The Electromyography (EMG) and pressure sensors are used to inform a hybrid control algorithm combining PID and model-based control methods. The method and results of the design and preliminary feasibility testing of the pneumatic muscle, the controlling algorithm, and the overall prototype are discussed in this paper. Based on these results, a wearable EMG controlled soft robotic arm augmentation could feasibly increase the endurance of industrial workers performing repetitive lifting tasks.
Fatigue Modeling of Friction-Stir-Welded (FSW) Butt-Joints for Aerospace Applications
Authors: Wahab Muhammad A. , Raghuram Vinay
Published: January 2020

Among the recent research Friction-Stir-Welding (FSW) has been adopted worldwide as one of the dominant processes for welding lightweight aerospace Aluminum alloys. Al-2195 which is one of the new generation Aluminum alloys has been used in the external tank of the space shuttles. Aerospace fabricators are continuously pursuing FSW-technologies in its efforts to advance fabrication of the external tanks of the space shuttles. The future launch vehicles with reusable mandates require the structures to have excellent fatigue properties and improved fatigue lives. The butt-welded specimens of Al-2195 and Al-2219 are fatigue tested according to ASTM-E647. The effects of stress ratios, use of corrosion preventive compound (CPC), and the applications of periodic overloading on fatigue lives are investigated in this study. Scanning-electron-microscopy (SEM) is used to examine the criticality of the failure surfaces and the different modes of crack propagation that could have been initiated into the materials. It is found that fatigue life increases with the increase in stress ratio, and results show an increase in fatigue life ranging over 30% with the use of CPC, and the fatigue life increases even further with periodic overloading; whereas crack-closure phenomenon predominates the fatigue fracture. Fracture mechanics analysis and crack similitude was modified for fatigue cracks by Paris. Numerical studies using FEA has produced a model for fatigue life prediction scheme for these structures, where a novel strategy of the interface element technique with critical bonding strength criterion for formation of new fracture surfaces has been used to model fatigue crack propagation lives. The linear elastic fracture mechanics stress intensity factor is calculated using FEA and the fatigue life predictions made using this method are within 10–20% of the experimental fatigue life data obtained. This method overcomes the limitation of the traditional node-release scheme and closely matches the physics of the crack propagation.
Three-Dimensional Velocity Field Measurements in Rugged Terrain Using Magnetic Resonance Velocimetry
Authors: Chung Daniel
Published: January 2020

Magnetic resonance imaging techniques were used to collect three-dimensional velocity data measurements of scaled models of a canyon in New Mexico to compare to simulations where a gas was released inside the canyon. The first canyon model covers an area of 1850m × 1030m with a scale of 1:5250 while the second model covers an area of 290m × 160m with a scale of 1:825. A fully turbulent flow with a Reynolds number of 36,000 using the channel hydraulic diameter passes through the canyon geometry for both models. With Magnetic Resonance Velocimetry (MRV), more than 13 million data points were measured to represent flow velocity. The MRV experiment with the 1:5250 scale model helped to identify key terrain features to be included in the next set of measurements of a higher resolution model. MRV not only served as a method of analysis but also as a method for design. The analysis of the data resulted in a new design of a 1:825 scale, which had a higher resolution of the terrain surrounding the gas release point. The preliminary scans from the 1:825 scale model showed a much more dynamic flow around the release point than observed in the 1:5250 scale model. Counter-rotating vortices and circulation can be observed in the 1:825 scale model. This data set will be used to compare to Sandia National Laboratories’ simulations of turbulent flows in a complex terrain.
Ultrasonic Vibration Assisted Milling of Aerospace Materials
Authors: Tapoglou Nikolaos , Taylor Chris
Published: January 2020

The machinability of aerospace grade alloys is a major concern in the production of components and is the focus of industrial and academic research projects. Assisted processes have emerged as a potential alternative for machining aerospace materials, increasing the material removal rate while not compromising the quality of the component. One of the assisted processes which have shown potential are ultrasonic (vibration assisted) processes. In these methods the tool is vibrated at a high frequency using an actuator, usually parallel to the depth of cut direction. In general this method is thought to be more effective when applied to hard materials. This research focuses on the machining of an aerospace material on a milling configuration using traditional and ultrasonic machining techniques. The results present the potential benefits of using ultrasonic machining techniques in machining difficult to machine alloys.
Performance of Prophylactic Knee Brace
Authors: Saboori Parisa , Corado Margarita
Published: January 2020

Female athletes are more likely to incur a knee injury compared to men when competing in the same sport. The increased risk is due to anatomical, biomechanical and hormonal differences between males and females. Women anatomically, have wider hips and this creates a greater quadriceps angle, which is the angle measured between the anterior superior iliac spine (ASIS), and a line that passes through the tibia trubercle and the middle of the patella (kneecap). Consequently, when landing after a jump, or making sudden movement, women tend to turn their feet inwards to compensate for a greater bending moment and this can result in knee injuries.

This work involved using a prophylactic brace to retrain the muscle memory of the leg and thereby promote correct landing technique. The brace geometry was based on data collected from 20 previous women athletes and was 3D printed using ABS to allow some basic customization. However, even though the results were somewhat promising, they were statistically inconclusive due to unforeseen braced design issues. Consequently, a new brace will be redesigned using the feedback from the participants and a new study will be undertaken.
Numerical Study of Particle Transport and Deposition in a Horizontal Channel Using a Lagrangian-Based Modelling Approach
Authors: Choi Byung-Hee , Orea Daniel , Nguyen Thien , Anand N. K. , Hassan Yassin , Sabharwall Piyush
Published: January 2020

Texas A&M University is participating in the U.S. Department of Energy (DOE) Office of Nuclear Energy’s Versatile Test Reactor (VTR) program to develop instrumentation and tools for a proposed fast spectrum test reactor. Our research project aims to develop and implement techniques to quantify the transport and deposition of fission products in the primary system of Gas Fast Reactors (GFRs) and ultimately in the reactor confinement. Developed techniques will be performed and tested in the NGNP Reactor Building experimental facility, which was previously 1/28 downscaled from General Atomics 350 MWth and built to study the reactor building responses to depressurization accidents. Prior to applying the techniques to the scaled facility, it is essential to verify and validate the performance of developing techniques using numerical simulations and quantify their associated uncertainties.

This manuscript presents our numerical study of particle transport and deposition in an experimental channel. The channel has three test sections, each has 3-inch square cross-section, 24 inches in length for a combined total length of 72 inches. The experimental facility is built using transparent materials, allowing the applications of non-intrusive, laser-based measurement techniques, such as Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV). Details of the experimental setup, measurement techniques, and results of flow field characteristics and particle transports in the channel will be presented in an accompanied manuscript.

The simulation domain is built upon the geometrical dimensions of the experimental facility, while upstream flow characteristics of the square channel obtained by PIV measurements are used as boundary conditions. State-of-the-art Lagrangian approach with random walk model is employed to investigate behaviors of surrogate particles within the square channel, coupled with computational fluid dynamics (CFD) model. While the main stream in the channel is solved by Eulerian turbulent model, motion of particles is tracked in Lagrangian framework. It is assumed that well-mixed air-particle mixture at a constant temperature is injected into the horizontal channel. Drag force, gravity force and turbophoresis force are adapted on this simulation and their competition are investigated.

Comparisons and validations of simulations and measurements on the flow fields downstream of the channel and characteristics of particle transports and depositions within the square channel will be systematically investigated. Experimental and numerical uncertainties will be quantified using the accepted standard approaches.
Effects of Laser Ablation Parameters to Pattern High Purity Magnesium Surfaces
Authors: Yayoglu Yahya E. , Gallant Nathan D. , Toomey Ryan , Crane Nathan B.
Published: January 2020

Magnesium and magnesium-based alloys have relatively low weight and desirable mechanical properties for many applications in multiple industries including aerospace and automotive. In the past decade, due to its biocompatible nature, the medical field has expressed significant interest in magnesium for biodegradable implant applications. However, utilization of magnesium-based alloys in surgical implant applications is strictly limited by magnesium’s high vulnerability to corrosion causing premature disintegration inside the human body. Hydrophobic (non-wetting) behavior of metal surfaces has been proven to be beneficial for corrosion protection in academic literature. One way of achieving hydrophobic and super-hydrophobic surfaces on metal surfaces without using non-biocompatible coatings is creating uniform microstructures that would alter the wetting characteristics of the surface. This work focuses on creating uniform pillar shaped micro-patterns on smooth pure magnesium surfaces by utilizing a picosecond laser (λ = 355 nm). The study reports the effects of average laser power, partial laser beam overlap and number of laser scans on the height, steepness, roughness of the resultant micro-pillars. Information gathered from this study could be useful in creating more complex or finer micro-structures on magnesium and its alloys to alter their wetting or corrosion characteristics using laser ablation which is a fast, repeatable and an un-convoluted process.
Development of a Skateboard for a Physically Disabled Child
Authors: Costa Ana Helena , L. R. Okimoto Maria Lucia , Cardozo Eloisa , A. Barbosa Maria Lilian
Published: January 2020

The aim of this paper is to present the development of a skateboard for a physically disabled child. The design presented in this study was motivated by an existing request of a local school that wanted to provide one of its students, a lower-limb amputee, with a more efficient method of transportation. Therefore, the design of an adapted skateboard, that values a healthy posture and an alternative propulsion system was proposed. For the product design, a user-centered methodology was applied based on the Project Development Orientation Guide. This methodology is divided in 8 stages and starts at the market opportunities and ends in the product testing. Hence, strategies of research and idea generation, such as articles and patents research, questionnaires, morphological matrix and SCAMPER tool, were used to develop a solution with a 3D model. With the model, a static simulation was performed through a finite element analysis method to validate the design and define the product’s dimension. The development of a product focused on the real needs of the user was highly approved. However, the user centered method presents significant challenges, especially dealing with a child and considering ethical standards in scientific research. The adapted skateboard represents a life quality improvement for the user and needs to be prototyped and tested for validation of the presented solution.