bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surrogate Modeling-Based Analysis of Concentration Decay in Diffusion-Reaction Mass Transfer Problems
Authors: Abbas Muhammad Mehdi , Jain Ankur 
Published: December 2024

Abstract
Diffusion-reaction phenomena occur commonly in heat and mass transfer problems. Determining the decay characteristics of such problems by solving the underlying energy/mass conservation equation is often mathematically cumbersome. In contrast, there is continued interest in simplified decay models that may offer reasonable accuracy at significantly reduced mathematical complexity. While simplified decay modeling has been presented before for pure diffusion problems, there remains a lack of similar work on diffusion-reaction problems. This work presents analysis of decay characteristics of diffusion-reaction problems using surrogate modeling, wherein the decay constant is determined using the moment matching method. Results are derived for homogeneous and two-layer Cartesian, cylindrical and spherical geometries. Under special conditions, results from this work are shown to correctly reduce to previously presented pure diffusion analysis. Good agreement with past work on a diffusion-reaction drug delivery problem is also demonstrated. Surrogate modeling using a single exponential function is shown to agree well with exact solutions. A two-term exponential model is also proposed to further reduce the error under certain conditions. This work extends surrogate decay modeling to the technologically important class of diffusion-reaction problems. Results presented here may help analyze and optimize several heat/mass transfer problems, such as drug delivery and reactor safety.
Solidification of a Liquid Column Between Two Rods of Unequal Sizes and Different Temperatures
Authors: Ho Nang X. , Nguyen Vinh T. , Vu Truong V. 
Published: December 2024

Abstract
A liquid column hanging between two surfaces (e.g., rod ends) appears in many engineering applications. This study focuses on its solidification with volume expansion through the use of an axisymmetric front-tracking method. The phase boundaries are handled by connecting points while the momentum and energy equations are solved on a fixed, rectangular grid. The rods holding the column in the vertical direction have different radii and temperatures and initiate solidification from their ends due to their temperatures smaller than the liquid melting point. As the upper rod is hotter than the lower rod, the lower phase-change interface moves faster than the upper one, resulting in an increase in the difference between the lengths of the upper and lower solid phases. The liquid phase changing into the lighter solid phase results in a ring formed near the midplane of the column at the end of solidification. The ring is located above the midplane and shifts more away from it as the upper rod has a higher temperature and a smaller radius than the lower rod. Increasing the upper rod radius or the column length or decreasing the Stefan number causes the solidification of the column to progress longer.
An Undulating Kirigami Pattern With Enhanced Tear Strength
Authors: Corrigan Tom , Xie Di , Srivastava Abhishek 
Published: December 2024

Abstract
Kirigami, the cutting and folding of sheets, can create useful three-dimensional shapes from flat sheets of material. Some kirigami patterns self-deploy from their flat state when tension is applied; we call these tension-activated kirigami (TAK) patterns. A new TAK pattern has been proposed that produces ribbons of material that undulate out of the plane of the kirigami sheet when deployed with tension. In the planar state, this pattern comprises staggered rows of multiple slits, so we call it the multi-slit pattern. The multiple slits can include two, three, or more slits in place of the widely studied single-slit kirigami pattern, with an increased number of undulations produced with additional slits. An enhancement is also proposed that increases the tear strength of this pattern by adding multiple beams to carry the tension forces that deploy and hold the structure. This multi-beam enhancement to the multi-slit pattern has been investigated with experiments and duplicated with finite element analysis simulations. A good correlation was found, and a broader design space was also investigated with additional simulations. It is proposed that the multi-slit undulating kirigami pattern, with or without the multi-beam enhancement, produces a compelling new deployed structure with increased interlocking and the potential for many applications.
Load-Side Dynamics Introduces Complex Effects on Orthotic Actuator Performance in Benchmarking
Authors: Sun Mingrui , Oetomo Denny , Tan Ying , Kulić Dana , Baček Tomislav 
Published: December 2024

Abstract
Series elastic actuators are increasingly adopted in wearable robots, due to superior sensing and actuating capabilities provided by the added internal compliance. However, when evaluating their performance in benchtop setups, the dynamics of the physical human–robot interface (i.e., external compliance) are usually overlooked despite it causing energy dissipation and delays in power transmission. This work closes the gap by emulating in a test bench the physical human–robot interaction dynamics and validating actuator performance against commonly used performance indices, including torque bandwidth, torque tracking, and transparency. The results show a significant impact of the interaction dynamics on the actuator performance. When interface dynamics is present, decreasing the actuator (internal) compliance has little to no effect on its bandwidth. When delivering a walking torque, decreasing internal (actuator) and external (interface) compliance has the same decreasing effect on the motor’s peak electrical power in the hip joint. Conversely, the motor peak electrical power decreases with an increase in internal (actuator) compliance but increases with an increase in external (interface) compliance in the knee joint. As such, this work demonstrates the importance of including interaction dynamics as a norm in designing and evaluating actuation units in wearable robots.
Flow and Heat Transfer in a Rotating Disc Cavity With Axial Throughflow at High-Speed Conditions
Authors: Wang Ruonan , Chew John W. , Gao Feng , Marxen Olaf 
Published: December 2024

Abstract
Flow and heat transfer in a compressor rotating disc cavity with axial throughflow is investigated using wall-modeled large-eddy simulations (WMLES). These are compared to measurements from recently published experiments and used to investigate high Reynolds number effects. The simulations use an open-source computational fluid dynamics solver with high parallel efficiency and employ the Boussinesq approximation for centrifugal buoyancy. Kinetic energy effects (characterized by Eckert number) are accounted for by scaling the thermal boundary conditions from static temperature to rotary stagnation temperature. The WMLES shows very encouraging agreement with experiments up to the highest Reynolds number tested, Reϕ=3.0×106. A further simulation at Reϕ=107 extends the investigation to an operating condition more representative of aero engine high-pressure compressors. The results support the scaling of shroud heat transfer found at lower Reϕ, but disc heat transfer is higher than expected from a simple extrapolation of lower Reϕ results. This is associated with transition to turbulence in the disc Ekman layers and is consistent with the boundary layer Reynolds numbers at this condition. The introduction of swirl in the axial throughflow, as may occur at engine conditions, could reduce the boundary layer Reynolds numbers and delay the transition.
High-Fidelity Investigation of Vortex Shedding From a Highly Loaded Turbine Blade
Authors: Gloerfelt Xavier , Cinnella Paola 
Published: December 2024

Abstract
High-fidelity numerical simulations based on wall-resolved large-eddy simulations (LESs) are used to investigate the vortex shedding dynamics in a linear turbine cascade. The profile geometry is the well-documented LS59 highly loaded rotor blade. The simulation campaign covered several outlet Mach numbers (subsonic and transonic) and several experimental configurations to shed light on the relations between vortex shedding frequency, the laminar or turbulent states of boundary layers, and the resulting cascade losses. A first major result concerned experiments for transonic outlet Mach number. LES without inlet turbulence and LES without tripping the suction-side boundary layer are unable to match the experimental flow field. In the untripped case, the recirculation bubble is shorter leading to a vortex shedding Strouhal number of 0.17, whereas in simulations with trip wire or inlet turbulence, the bubble was longer, with a Strouhal of 0.24. A second finding is that the inlet turbulence intensity is able to drive the switching between two regimes for subsonic outlet Mach numbers: the so-called detached vortex shedding (long bubble, St∼0.24) or a “transonic vortex shedding” (short bubble, St∼0.19). The appearance of shock waves and very coherent rolls in the wake for the “transonic” regime can lead to a doubling of the cascade losses due to the drastic pressure drop near the trailing edge. Such a change in the flow regime, due solely to an increase in freestream turbulence, has not been reported earlier.
An Active Turbulence Grid for Turbomachinery Flow Experiments
Authors: Bertelli Federico , Okada Mizuki , Lavagnoli Sergio , Hillewaert Koen 
Published: December 2024

Abstract
Quantifying and predicting the effects of freestream turbulence on the aerodynamic performance of turbomachinery flows continues to be of primary interest to advance the physical understanding and modeling of loss mechanisms. This work is motivated by the need to expose turbine flows to a wide class of inlet turbulence fields, characterized by the peculiarity of setting the turbulence intensity levels and yet tuning the turbulence scales independently. This article describes the development and experimental characterization of an active turbulence generator concept that provides the authority to enable future experimental measurements in turbine cascade rigs. The study has been conducted in an auxiliary low-speed test bench with a small cross-sectional area, testing at low Mach numbers (∼0.05) and ambient conditions. Pressure, hot-wire anemometry, and particle image velocimetry (PIV) measurements are presented. The results indicate that the active turbulence generator is capable of generating a wide range of homogeneous and isotropic freestream turbulence. Turbulence levels in the range of 1.5–13% with minimum pressure losses and a low degree of nonuniformity (&lt;5%) have been obtained with the ability to independently control the integral length scale within the range of 6–25 mm.
Autonomous Satellite Servicing Infrastructure for In-Space Assembly and Manufacturing
Authors: Down Ian M. , van Wijk David E. J. , Parikh Deep , Majji Manoranjan 
Published: December 2024

Abstract
This work examines the closed-loop deployment of spacecraft servicing modules onto an uncontrolled bundle of assembly components as a method of gaining custody during the in-space assembly process. Minimum energy, low-thrust relative trajectories are generated using indirect optimal control on linear dynamics over a finite time search horizon. A line search solves for the minimum energy solution in the closed subset that satisfies a keep out zone constraint. A trajectory tracking linear quadratic regulator is used in conjunction with an extended Kalman filter to closed-loop maneuver the spacecraft under nonlinear relative orbital motion dynamics. Bearing angles, range, and range rate measurements are assumed available. Launch ΔV’s from the servicer spacecraft’s deployment of a module and the ΔV’s seen in the relative frame upon impact on the client are included, and their effect on covariance due to impact site uncertainty is investigated. Discussions regarding these GN&C elements’ importance within the context of the manufacturing/assembly process are included.
Application of PyAnsys for Level 3 Assessment Tool Development
Authors: Bao Ji , Zhang Shenwei , Zhang Billy 
Published: December 2024

Abstract
Finite Element Analysis (FEA) is a prevalent tool for the integrity assessment of pipelines in the industry and is widely acknowledged by industrial standards such as CSA Z662 and CFR 192.712. Previous research has established the capability of FEA to accurately simulate the response of pipelines under various loading scenarios, demonstrating high fidelity in processes like dent simulation and predicting the failure of corroded pipelines.
The Finite Element method is a complex numerical technique that involves discretizing a continuous pipeline into small finite elements. While the accessibility of commercial FEA software tools has facilitated the application of this method, challenges and potential issues persist. Firstly, FEA simulations generate substantial amounts of data, including nodal solutions and stiffness matrices. Secondly, debugging can be intricate, necessitating a combination of experience and specialized knowledge. Thirdly, postprocessing can be time-consuming; for instance, calculating the Ductile Failure Damage Indicator (DFDI) involves integrating stress components across all time steps. Lastly, commercial FEA software typically operates as closed source, limiting customization options to the features provided by the software.
This paper introduces the use of a Python-based FEA library, PyAnsys, offering a more accessible and streamlined approach to managing the extensive data generated by FEA simulations. The integration of PyAnsys with Python enhances the debugging process by providing an intuitive and user-friendly scripting interface. Python’s readability and extensive debugging tools contribute to a smoother debugging experience, reducing the dependency on specialized knowledge. Additionally, PyAnsys facilitates efficient pre-processing and post-processing by leveraging the power of Python. The open-source nature of PyAnsys enhances customization options, allowing integration with other Python libraries, such as the visualization package PyVista, making PyAnsys a versatile and powerful tool for FEA applications.
Two case studies are presented in the paper to demonstrate the effectiveness of PyAnsys. The first case study utilizes PyAnsys to analyze a dented pipe in structural analysis, while the second case study involves study simulating a corroded pipeline to evaluate the load carrying capacity of a pipeline containing metal loss corrosions.
Effective Anomaly Management Approach for Class Location Change With Engineering Assessment
Authors: Al-Amin Mohammad , Zhang Shenwei , Kariyawasam Shahani 
Published: December 2024

Abstract
Canadian Standard Association (CSA) Z662 allows pipeline operators to perform engineering assessment (EA) to determine the suitability for continued operation of the existing pipeline at the new class location designation instead of pipe replacement or pressure reduction. Canadian Energy Regulator (CER) filing manual guide E provides the filing requirements for class location change EAs. However, there is no clear guideline in CSA Z662 or CER filing manual guide E on how to assess and manage pipeline anomalies (e.g., corrosion and cracking) on a pipeline operating with a class change managed under an EA.
CSA Z662-23 Clause 10.7.2 requires evaluation and repair of imperfections per Clause 10.10 and Clause 10.11 for class location change pipeline segments. However, no explicit guidelines are provided regarding which location factor is to be used when the class location changes from a lower class to higher class with an EA. The most common perception is that the location factor based on the new higher class should be used in a class location change scenario. This leads to the question whether a pipeline segment which is designed for a lower class location can have an appropriate response criterion (i.e., acceptable FPR level) based on a higher class location. The authors performed an in-depth analysis to address this question. These results are explained in this paper. The anomaly assessment and response process presented in this paper combines a deterministic FPR based assessment and a probabilistic assessment to effectively manage anomalies on class location change pipeline segments. The proposed process will ensure safe and consistent response requirement for anomalies identified in pipeline segments with class location changes.
Key Elements to Consider When Managing Circumferential SCC In Pipelines
Authors: Guillen Pedro , Merotto Fernando , Monteiro Larissa , Gamboa Erwin 
Published: December 2024

Abstract
In recent years, stress corrosion cracking (SCC) has become a more prevalent threat to pipeline integrity worldwide; SCC only occurs in a specific combination of a susceptible material, environment, and tensile stress at a particular location. In pipeline systems, the main SCC driving stress — from internal pressure — favors axial rather than circumferential SCC (CSCC). However, under certain conditions, such as excessive soil loads, high residual axial stresses from construction, etc., axial loading can reach the threshold for CSCC to initiate and propagate. Although in a smaller proportion when compared to axial SCC, CSCC incidence has also increased in the pipeline industry. Similar to any other integrity threat, a holistic approach is required to manage it; once a pipeline has been identified to be susceptible to CSCC, the next stage is to assess its extent in the system, understand the pipeline locations with active CSCC, and implement adequate repair and mitigation actions.
Using only crack ILI to assess the extent of CSCC in a pipeline can be challenging due to limitations in currently available ILI technologies, especially for gas pipelines. Thus, direct assessment becomes a key supporting task at this initial stage of the management process; combining relevant data sets will help to define areas more susceptible to CSCC. Combining this information with ILI outcomes, when available, will help to develop and implement a more effective management plan. Although SCC direct assessment industry guidance is available, a CSCC-focused susceptibility model should be developed for each pipeline.
This paper describes a proposed approach to managing CSCC in pipelines, which combines applicable data based on CSCC specific drivers, such as geohazards and construction features along the pipeline, pipe material data and cathodic protection (CP) performance. Hence, different layers of information are considered, including the pipeline data book and available ILI datasets (e.g., MFL, geometric inspection, historic CP surveys, visual inspections, and field verification data). In fact, this document includes a review of the main factors affecting CSCC in a gas pipeline with the aim of identifying those that should be considered in the susceptibility model; it also includes an example of elements considered for a specific pipeline whit CSCC present. Furthermore, it reviews the relevance of ILI when dealing with this threat, available ILI technologies and their possible limitations, and uncertainties and how to manage them. Finally, relevant mitigation and other actions aimed to manage this threat are also discussed.
Development of a SCC Crack Growth Rate Calculator
Authors: Gamboa Erwin , Wynne Andrew 
Published: December 2024

Abstract
Estimation of representative Crack Growth Rates (CGR) for pipelines with confirmed Stress Corrosion Cracking (SCC) is an Integrity management challenge.
Published rates used within the industry can be unreliable, as most estimates assume a particular range of time periods for when cracks initiated, without providing reliable evidence for when crack initiation occurred. Also, little detail is provided to help assess whether the published rate could be applied to similar asset of interest. Laboratory testing (often used to determine industry published CGRs) tends to be under Stage II growth conditions where the CGRs are known to be much higher than compared to Stage III conditions. As a result, reported maximum CGRs can vary greatly from approximately 5 mm/yr (from laboratory testing) to approximately 0.8 mm/yr (from infield estimates, where operational conditions are not generally provided). These values are known to be very conservative, so a “rule of thumb” rate of 0.3 mm/yr is commonly used throughout the pipeline industry as an SCC growth rate. This estimate of 0.3 mm/yr is still considered to be conservatively aggressive when compared with reliably obtained rates of 0.15 mm/yr or lower.
To support operators, an SCC Crack Growth Rate Calculator has been developed to bring together the different parameters known to affect SCC crack growth rates in order to provide an initial, conservative crack growth rate for individual anomalies (reported or hypothetical) located along a specific pipeline.
Establishing the Value of Pre-1970 (Non-Subpart J) Pressure Tests for MAOP Determination
Authors: Mittelstadt Benjamin C. , Nicholson Matthew , Delong Terry , Jimenez Brian 
Published: December 2024

Abstract
This paper presents a technical discussion of pre-regulation (i.e., pre-1970) pressure testing and specifically the engineering value of legacy test records for use in activities such as fitness for service when considering manufacturing-related threats or establishing Maximum Allowable Operating Pressure (MAOP) of pipelines.
The requirements associated with 49 CFR 192 Subpart J and specifically §192.517, records of each test performed, were first introduced in August of 1970. Prior to this time, pressure testing was addressed within industry standard ASA (American Standards Association) Code B31.1 with varying guidance for the performance of the test and associated record keeping. The requirement for pressure test records to contain all information listed in §192.517 is reasonable for pressure tests performed after 1970. Pressure tests performed prior to the promulgation of the record keeping requirements are unlikely to contain all information required under §192.517, however not all elements of §192.517 have engineering value when establishing the efficacy of a pressure test.
Certain information is required to understand the stress applied to the pipeline during a pressure test. This information includes pressure levels at each location along the segment, elevation, and test medium. Some of this information must be obtained from the records, other information can be researched and derived from other sources.