bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forebody Optimization Using Response Surface Methodology With Genetic Algorithm
Authors: Kandemir Omer , Tuncer Ismail H. 
Published: January 2022

Abstract
Aerodynamic design of a forebody geometry has a significant effect on aircraft performance and stability. Although the studies conducted on aircraft performance so far, mostly, focus on optimization of wing-like structures, the contribution coming from an effective forebody design to the aircraft performance could be as high as the contribution coming from wing-like structures. A proper forebody design can reduce the wave drag and provide better lateral characteristics at high angles of attack. The reduced drag may enable the aircraft to achieve higher speeds and consume less fuel which eventually results in higher endurance and range to be achieved. On the other hand, achieving better lateral characteristics at high angles of attack may enable aircraft to withstand higher gust loads during take-off and landing phases. In addition to that, it may provide improved spin characteristics. In this paper, the forebody optimization of a jet trainer aircraft is studied. While doing so, two objectives are considered. Turbulent flow solutions are obtained with SU2. Response surface methodology is used as database generator and Pareto-optimal solutions are searched by using non-dominated sorting genetic algorithm–II. The optimization study improves the aircraft performance in the aspects of the wave drag and the lateral stability.
Potentials for PdAgCu Metal Hydrides Energy Simulations
Authors: Hijazi Iyad , Zhang Chaonan , Fuller Robert 
Published: January 2022

Abstract
Palladium hydride (Pd-H) is a metallic palladium that can absorb substantial amount of H at room temperature. Because this H absorption is recoverable, it can be utilized in a variety of energy applications. When Pd is alloyed with silver (Ag), sulfur poisoning remains a problem, but adding Ag improves Pd mechanical properties, boosts hydrogen permeability and solubility, and narrows the Pd-H system miscibility gap region. Pd alloyed with copper (Cu) has a lower H permeability and solubility compared to pure Pd and Pd-Ag alloys, but adding Cu gives better sulfur and carbon monoxide poisoning resistance and hydrogen embrittlement resistance, as well as better mechanical properties and a wider operating temperature range than pure Pd. These findings show that alloying Pd with a mix of Ag and Cu to make Pd-Ag-Cu ternary alloys improves Pd’s overall performance while also lowering its cost. Thus, in this paper, we provide the first embedded atom method potentials (EAM) for the quaternary hydrides Pd1-y-zAgyCuzHx. The EAM potentials can capture the preferred H occupancy locations, and determine the trends for the cohesive energies, lattice constants and elastic constants during MD simulations. The potentials also captured the existence of a miscibility gap for the Pd1-y-zAgyCuzHx and predicted it to narrow and disappear when Ag and Cu concentration increases, as was predicted by the experimental findings.
A Control Oriented Soot Prediction Model for Diesel Engines Using an Integrated Approach
Authors: Shewale Mahesh S. , Razban Ali 
Published: January 2022

Abstract
Diesel engines have been used in many vehicles and power generation units since a long time due to their less fuel consumption and high trustworthiness. With reference to upcoming emission norms, various engine out emissions have proved to be causing adverse effect on human health and environment. Soot, or particulate matter is one of the major pollutants in diesel engine out emissions and causes various lung related issues. There have been efforts to reduce the amount of soot generated using after-treatment devices like diesel particulate filter (DPF) to filter out particles and get clean tailpipe emissions. These technologies increase load on the system and involves additional maintenance. Also, deposition-based soot sensors have been found to be inoperative in certain scenarios like cold start conditions. In this research work, an effort has been made to develop a phenomenological model that predicts soot mass generated in a Cummins 6.7L diesel engine. The model uses in-cylinder conditions such as pressure, bulk mean temperature, fuel mass flow rate and injector orifice diameter. The difference between soot mass formed and oxidized yields the net amount of soot generated at engine out end. Furthermore, the generated soot mass is compared with benchmark results for specific load conditions and appropriate controller is designed to minimize this tradeoff. The control parameter being used here is fuel rail pressure, which controls the lift-off length, and ultimately equivalence ratio, which predicts mass of soot, generated in formation phase. The presented method shows a prediction error ranging from 5–20%, which is significantly reduced to 2% using a PID controller. The approach presented in this research work is generic and can be operated as stand-alone system or an integrated subsystem in a higher order control architecture.
On the Use of Probabilistic Risk Assessment for the Protection of Small Modular Reactors Against Terrorist Attacks
Authors: Polat Burak , Diaconeasa Mihai A. 
Published: January 2022

Abstract
Safety and security are two of the most important requirements of the nuclear industry. In the event of a potential problem, the consequences can have serious implications for the public and the environment. Measures should be taken against various hazards and threats by analyzing possible realistic scenarios. Therefore, probabilistic risk assessment is one of the necessary technologies to achieving safe and secure nuclear facilities. In the study, a limited scope probabilistic risk assessment was made for a possible terrorist attack against a generic small modular reactor (SMR). A possible attack threat was selected to develop scenarios by following a probabilistic risk assessment approach.
In the scenarios created, terrorists have to pass all physical barriers that security guards protect. Thus, the decisions and actions of the security guards directly affect the result of the attack. To analyze these events, a human reliability assessment (HRA) was employed. In the first study, each security guard’s decision-making process was analyzed using the Standardized Plant Analysis Risk Human Reliability Assessment (SPAR-H) method. The purpose of its use in this study is to verify the SPAR-H method’s applicability for security applications.
In this paper, we give the likelihoods of each security guard making a decision and taking action to prevent terrorists from passing obtained using the SPAR-H method. Besides, event tree and fault tree analyses were performed using the SAPHIRE PRA software.
Finally, since the current HRA methods were designed for control room operators, we introduce a new model-based HRA methodology applicable for security guards to be used in physical security PRAs.
Study of Flexural Strength and Fracture of Additive Manufactured Parts With Stiffeners
Authors: Regalla Srinivasa Prakash , Shyam P. V. , Mylavarapu Sampath , Irigineni Sai Harshini , Shrivastava Prakash Narayan 
Published: January 2022

Abstract
The authors have developed trans-tibial prosthetic sockets using additive manufacturing. These sockets made with mono-material thermoplastics such as Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA) at lower thicknesses were found to fracture within a few days of use by the amputees. The fracture was repeatedly found to occur at specific locations such as the lobe corners and the socket’s lower one-third zone. The most probable causes of crack initiation are lack of fusion (LOF) sites and voids. The causes of crack propagation are the lower interlayer bond strength compared to intra-layer bond strength. However, no scientific work exists that clearly explains these phenomena and methods to prevent such potential crack initiation sites and arrest the propagation of such fracture in additively manufactured polymeric structures. Therefore, in the present work, the investigation was carried out into possible enhancement in the resistance to fracture by different strength-enhancing post-processing techniques. In the first technique, the placement of stiffener features at selected locations on the socket was investigated. Three-point bending tests were carried out on D790 standard ABS specimens with different stiffeners introduced on the bottom face. The study focused on fracture characteristics in the stiffener-based topologically optimized geometric design of plate structures made by Fused Deposition Modeling (FDM) under flexural loading. The D790 three-point bending specimens were provided with differently shaped stiffeners, namely, triangular, prismatic, cuboidal, and pyramidal, extending all along the specimen’s length and spread with differential gaps in the width direction. In the second method, thermosetting epoxy resin coatings were applied on the three-point bending specimens of ABS, and the effect of the coating on the flexural strength was investigated. Bending tests were done on three specimens, the first specimen without any coating, the second specimen with only the epoxy resin coating, and the third specimen with two different coating layers. The first of the two coating layers on the third specimen was with primer and the second layer was with epoxy resin. Scanning electron microscope (SEM) and energy dispersion spectroscopy (EDS) scanning analyses were conducted on the fractured specimens. The scanning images indicated that both the primer and resin materials showed a tendency to diffuse into the substrate of ABS, thereby weakening the extreme fibers of material on the specimen’s tension side, resulting in premature crack initiation and propagation. Significant gain in the flexural strength was observed in both the strength enhancement techniques compared to plain specimens.
An Analytical Model for Predicting the Deflection of Hollow Surgical Needle in Soft Tissue
Authors: Al-Safadi Samer , Hutapea Parsaoran 
Published: January 2022

Abstract
Considerable research efforts have been devoted for studying the interaction between surgical needles and soft tissues which can be used to evaluate the deflection of a bevel-tip needle inside a tissue. The development of an analytical model to predict the steering behavior of the needle during needle-tissue interactions could improve the performance of many percutaneous needle-based procedures. In this study, Euler-Bernoulli beam elastic foundation theory was utilized to model the needle as a cantilever beam moving along its longitudinal axis and undergoing various external loads. The external loads are the result of the interaction between the tissue and the needle during insertion, they can be modeled as a concentrated tissue cutting force acting at the needle bevel, and needle-tissue interaction forces acting along the needle length and tangent to the needle shaft. The accuracy of the analytical predictions offered by the model are verified by comparing them to the experimental data. Due to the assumption of the elastic tissue material, the difference between the analytical model and the experimental results was between 15% to 33%. Current work is ongoing to consider tissue viscoelastic properties to improve the analytical prediction.
Double Curved Panel Forming With Bespoke Slits
Authors: Mertens Jonas , Troi Valentine , Maleczek Rupert 
Published: January 2022

Abstract
In this publication, the authors show and discuss a method, that allows the forming of flat sheets of material to a wished three-dimensional state, based on bespoke slits cut into the sheet.
Especially a method known as Kerf is investigated. As current methods are using a grid of slits from border to border in linear or orthogonal crossing configuration, the authors are presenting a method with slits based on surface curvature. The bespoke slits can be straight or curved and must not be from border to border of the sheet-material. Depending on the curvature, the slits can cross. The method is applicable for developable and with strong limitations for non-developable surfaces.
The authors will explain their method that analyses a given target surface’s curvature and generates a slit pattern of smooth planar curves on a 2D development of Surfaces. The pattern relates a physical slit, that will be closed until the upper gap is closed. The Angle of the closed gap defines a target angle. In this paper the described slits have a constant angle and a constant depth. but can have different cross sections namely a V- and U-shaped one. The paper focuses on the geometric generation of the slits and will show and analyze some results.
As the investigation is done in the context of architecture, the authors are mainly considering a pure geometric approach that is not taking into account different physical material properties.
Heat Transfer Enhancement of Counter Flow Heat Exchanger With Pin Fins
Authors: Molham Ibrahim Daadoua Mohammed , Alnaimat Fadi , Ziauddin Mohammed 
Published: January 2022

Abstract
Heat exchangers with microchannel/mini-channel configurations have wide applications including aerospace, air-conditioning, process/power industries, gas turbine cooling, etc. Heat sinks are effective due to the main feature of having fins, however, there are limitations with respect to their applications. The main objective of this study is to observe the changes in the performance of the heat exchanger by calculating effectiveness with respect to Reynolds number, pin fins (two types: circular and square), and operating conditions. The current study is conducted through Computational Fluid Dynamics (CFD) analysis using ANSYS Fluent solver platform. The CFD geometric model consisted of a top channel with hot fluid (air), the bottom channel (water), and the middle part, aluminum block. Overall, it is noted that the heat transfer is enhanced by adding pin fins along the mini-channel of the heat exchanger. The findings indicated that square fins perform slightly better than circular fins.
Non-Intrusive Parametric Reduced Order Models For The Prediction Of Internal And External Flow Fields Over Automobile Geometries
Authors: Rezaian Elnaz , Biswas Rajarshi , Duraisamy Karthik 
Published: January 2022

Abstract
In many-query applications such as design, optimization, and model-predictive control, reduced order models (ROMs) have the potential to significantly decrease the computational cost. In contrast to intrusive projection-based ROMs which require direct access to the high-fidelity model (HFM) operators, non-intrusive ROMs can be constructed in a data-driven fashion using the input-output data generated by the HFM. When used in the prediction of the system response in unseen parameter regimes, however, generalization capabilities have to be carefully assessed. In this study, we pursue a two-step approach to construct non-intrusive parametric ROMs: The first step involves the extraction of low-dimensional latent spaces using proper-orthogonal decomposition (POD) and convolutional neural network-based autoencoders (CNN-AE); and the second step uses regression for the latent variables in parameter space. We adapt a unique decomposition approach named Split-POD to enrich the low-dimensional subspace of the parametric ROM. The proposed methods are used to predict the flow field over a vehicle geometry as a function of vehicle speed and internal fan speed. Through orders of magnitude reduction in the degrees of freedom, the non-intrusive ROMs enable flow field prediction in real-time and bypass hours of computations by the HFM. The results show that the nonlinear encoding in CNN-AE can enhance ROM predictions given adequate data. POD-based ROMs are more robust and efficient, and in particular more accurate than CNN-AE in under-sampled regions of the parameter space. We further enhance the utility of non-intrusive ROMs by formulating a training process that minimizes the required number of high-fidelity simulations using Gaussian process regression to adaptively sample the input parameter space and optimize the estimated variance of the predictions.
Application of Oxygen-Enriched Combustion in an Industrial Reheating Furnace Using CFD
Authors: Worl Bethany , Martinez Francisco , Li Xiang , Silaen Armin K. , Johnson Kurt , Fabina Larry , Tian Kelly , Maiolo Joe , Zhou Chenn 
Published: January 2022

Abstract
The most energy intensive part of a hot rolling mill is the reheat furnace, where the steel products, the products are heated to target temperature using the combustion of natural gas. The energy consumption of the reheat furnace in a typical integrated steel mill is the second highest after blast furnace. Any improvement to energy efficiency of the reheat furnace can have significant impact on the overall energy efficiency of the steel plant. Oxygen enrichment of the combustion air beyond 21 vol% oxygen can be used to improve the furnace energy efficiency. The molar fraction of oxygen is increased, replacing nitrogen in the combustion air. In this study, computational fluid dynamics modeling of various burner configurations was conducted to investigate the application of oxygen enrichment or oxy-fuel to reduce fuel usage while maintain a given slab heating rate. The applications of medium oxygen enrichment (46 vol% O2) and oxy-fuel (100 vol% O2) in the preheating zone, which has the highest fuel usage of the three furnace zones, were investigated.
Investigation of Microstructure and Mechanical Properties of Additive Manufactured AISI - 420 Martensitic Steel Developed by Directed Energy Deposition Method
Authors: Hassan Md Mehadi , Radhakrishnan Madhavan , Otazu David , Lienert Thomas , Anderoglu Osman 
Published: January 2022

Abstract
The traditional manufacturing approach to produce engineering components can have a high energy cost, high material waste, longer delivery times, and specific geometries that may be unattainable. The recent developments in additive manufacturing might provide the opportunity to produce complex engineering components, reduced manufacturing costs, and reduced delivery times. Direct Energy Deposition (DED) offers excellent possibilities such as fabrication of metal components with complex geometries, repair of high-value equipment, development of functionally graded materials, and large-scale additive fabrication or repair. This work focuses on the fabrication of AISI 420 martensitic steel using DED for the application of the aerospace, automotive, and medical industries. AISI 420 martensitic steel (12.7%Cr, 0.4%C in wt.%) was successfully deposited onto 316L substrate by a Laser Engineered Net Shaping (LENS®) process carried out in an open atmosphere. The cross-sectional examination by electron microscopy and XRD confirms the dual-phase microstructure of martensitic needles in random orientation and approximately 22 wt. % of austenite lamellar phase by Rietveld refinement and quantitative phase analysis. There are no cracks observed throughout the materials. However, the area fraction of porosity was found to be 0.4%, with the max size of 2μm. Preliminary mechanical characterization by micro-Vickers hardness tests shows uniform hardness about 725 (HV) trend across the build. The microstructure, the chemical composition of the phases, and the mechanical properties of the steel could be affected by the post-heat treatment, which is very sensitive. The team investigates to optimize the heat-treating method to improve the microstructure and mechanical properties.
Investigating the Flow Field Physics Within Unsteady Compressible Flows
Authors: Feng Dehua , Gao Yang , Thompson Larry , Ferguson Frederick 
Published: January 2022

Abstract
Computational Fluid Dynamics (CFD) continues to play a critical role in the solution of complex fluid dynamics flows. This computational tool allows us to investigate complex flow patterns that would otherwise be impossible to investigate and has greatly aided in the development of our knowledgebase. At the Heart of successful CFD tools are creative numerical schemes that are developed and used in an attempt to capture ‘real world’ flow physics. One such creative numerical scheme in the Integro-Differential Scheme (IDS) has be created. In previous studies, the IDS Scheme has demonstrated that it has achieved adequate dispersion and dissipation capabilities in the smooth flow field regions along with very robust shock-capturing capabilities in the vicinity of discontinuities. In this proposed paper, the IDS Scheme will focus on unsteady fluid motion like Rayleigh-Taylor Instability problem as an example with 2nd order accuracy in space and 3rd order of accuracy in time. Initial perturbations will lead to bubbles and mushroom-shaped spikes due to the release of potential energy, which is from a linear growth phase into a non-linear growth phase. The Total Variation Diminishing Runge-Kutta (TVD-RK3) Scheme will be applied in IDS Scheme and shows incredible results. The detail of how eddies are formatting and interact will be proposed in this paper. Also, IDS Scheme shows its capability to capture more eddies which WENO 5th order is not shown with same computational grids. The IDS simulations are governed by the full set of Navier-Stokes Equations (NES) and focus on the basic flow structure and their interaction which lead to complex flow phenomena. The numerical form of the IDS to be used for solving these compressible flow field problems will consist of the coupled 3rd order Runge-Kutta explicit time marching method and an explicit spatial integral method for the control volume convective flux evaluation. The accuracy and resolution of the unsteady IDS scheme will be tested by its simulations of several benchmark unsteady compressible test cases. Already, evidence of the IDS capability is demonstrated in its simulating solution of the unsteady Rayleigh-Taylor problem.