bluuebunny/crossref_metadata_2025_split huggingface dataset:
Updating Turbomachinery Aerodynamics Teaching on an Undergraduate Course Using Three-Dimensional Design Tools
Authors: Ingram Grant 
Published: November 2023

Abstract
This paper outlines the update of a turbomachinery course to cover three-dimensional (3D) aerodynamics using a Reynolds-Averaged Navier Stokes solver. Prior to the activities outlined in this paper, the course was taught in a conventional way with a series of lectures and a timed, written, open book examination in a formal exam setting. Students were equipped with a calculator and set of notes including correlations from Howell and Soderberg. The students had around 1 h to answer the turbomachinery question, which was revealed to them only when they opened the paper at the start of the exam. This limited the depth of any aerodynamic problem they could get through and so they were restricted to simple design or analysis exercises. The genesis of the course update was the release in 2017 of “MULTALL OPEN” (Denton, J. D., 2017, “Multall: An Open Source, Computational Fluid Dynamics Based, Turbomachinery Design System,” ASME J. Turbomach., 139(12), p. 121001), a freely available turbomachinery design system, and this was adopted as the course software—although other software choices were considered. Students now produce two turbomachinery designs during the course. These are both based on the J85 turbojet—largely to keep cycle calculations to a minimum but it was also important to ensure that students recognize that they were completing a real engineering task. The first task was a 3D aerodynamic design of multistage turbine, which includes compressible flow, tip clearance, and stacking techniques such as lean or sweep. The second task was a midspan (two-dimensional) compressor design. The exact cycle conditions were varied each year to explore design scenarios such as an increase in firing temperature. Assessment was by means of a short report where the best students report on their design choices, provide critical analysis of the design using appropriate postprocessing techniques, and compare their designs to the state of the art in the wider literature. As well as describing the successes and challenges of the update to 3D design methods the paper provides some guidance for educators thinking about adopting a similar approach.
Experimental Study on Thermal Management of Nano-Enhanced Phase Change Material Integrated Battery Pack
Authors: Vali P. S. N. Masthan , Murali G. 
Published: November 2023

Abstract
In recent years, lithium-ion batteries (LIBs) have gained attention and popularity due to their extended cycle life and high energy density. A hexagon-shaped 18,650 lithium-ion cylindrical cell battery pack was designed, incorporating paraffin wax (PA) as a phase change material (PCM) and nano-enhanced phase change material (Ne-PCM). However, the low thermal conductivity of the PCM causes a significant challenge to the development of electric vehicles (EVs). The highest temperature in the cylindrical cell battery pack is reached in the midregion, leading to an uneven temperature distribution across the cells. To overcome these challenges and achieve efficient battery module performance, phase change with nanomaterials such as graphene platelet nanopowder (GPN), multiwalled carbon nanotubes (MWCNTs), and graphite-synthetic powder (GSP) was placed in the center of four cells. Studies on the battery module were conducted without cooling, with PCM cooling, and with Ne-PCM cooling. The investigation revealed that the battery pack with Ne-PCM performed well, maintaining the temperature below 50 °C at different discharge rates of 1C, 2C, and 3C, and ensuring a uniform temperature variation within the cells. Ne-PCM decreased the temperature differential between the modules at 1C, 2C, and 3C discharge rates by 85.49%, 91.47%, and 84.21%, respectively, compared to PCM.
Uncertainties in In-Structure Response Spectra Due to Uncertainties in Input Motion Amplitude and Phase Spectra
Authors: Nie Jinsuo R. , Xu Jim , Graizer Vladimir , Seber Dogan 
Published: November 2023

Abstract
We concluded in PVP2020-21132 that the four or five time histories in the current practice are not sufficient for estimating stable mean in-structure response spectra (ISRS), therefore a check of their power spectral density functions is necessary. The time histories used in that work were not developed based on typical response spectrum (RS) convergence criteria and did not consider the uncertainties in Fourier amplitude spectra. This paper examines how the uncertainties in both Fourier phase spectra and Fourier amplitude spectra of the input motions resulting from seed time histories and a new RS-matching algorithm affect the uncertainties in ISRS. This study finds that the coefficient of variation in ISRS reached as high as 68%, generally confirming previous results obtained using a different RS-matching algorithm. This level of ISRS variation continues to support our conclusions in PVP2020-21132. Therefore, a check of the power spectral density functions of the multiple input time histories in the current practice is necessary to ensure the estimated mean ISRS would vary on the conservative side, although not as stable as necessarily required for reasonable confidence levels. These results provide the necessary technical bases for consistent technical positions between industry standards and regulatory guide for nuclear power plants.
Experimental Evaluation of Contribution of Content Liquid to Uplift Commencement Condition of Cylindrical Liquid Storage Tanks Subject to Horizontal Base Excitation
Authors: Yoshida Yuichi , Taniguchi Tomoyo 
Published: November 2023

Abstract
This study experimentally investigates contribution of content liquid to the uplift commencement condition of flat-bottom cylindrical shell tanks subjected to the horizontal base excitation. The conventional analytical models assume that the tank bottom plate uplifts when the overturning moment overcomes the resistant moment consisting of dead weight of a side shell (including the fixed roof and the appurtenances). In other words, the conventional uplifting resistance system in tanks does not implicitly expect any contribution of the content liquid to it.
In this study, a tank model made of PVC was set on a shaking table and the required horizontal acceleration to commence uplift of the tank bottom plate was investigated by increasing the amplitude of the horizontal sinusoidal base excitation step by step. In this experiment, several aspect ratios (Liquid depth / Diameter = 0.25, 0.30, 0.35, 0.40) of the content liquid, which were adjusted by changing the liquid depth, were used. Despite aspect ratio of tanks, the observed acceleration required to commence uplift was larger than that estimated from the conventional analytical model. These results imply existence of the content liquid contributing to the uplift commencement condition of the liquid storage tanks and necessity of its quantification.
Literature Review on Testing of Mini-CT Specimen to Characterize the Ductile-to-Brittle Transition Range and the Upper Shelf Regime
Authors: Sánchez Marcos , Cicero Sergio , Arrieta Sergio 
Published: November 2023

Abstract
In recent years there have been significant research efforts toward the miniaturization of specimens when characterizing the fracture toughness of ferritic steels. In particular, the nuclear sector has been especially interested due to the strict structural integrity controls to which the different nuclear components are subjected, with the reactor pressure vessel being one of the most critical. In this sense, the use of the mini-CT specimen (a compact tension 4 mm thick specimen) constitutes a promising alternative that has been widely studied together with the Master Curve approach to characterize steels within the ductile to brittle transition range. Additionally, this type of specimen has also been used to characterize steel operating within the upper shelf regime. Within the transition regime, the majority of the results reveal an excellent correlation between the results obtained using mini-CT specimens and those obtained when using well-known conventional size specimens (e.g., 1T-CT specimens or PCCv specimens), which seems not to be the case when dealing the ductile regime. However, testing such a small geometry brings a series of peculiarities that are necessary to consider. This work intends to briefly gather the knowledge found in the literature and to expose the best practices when testing this type of specimen. The effect of the specimen geometry, the possible use of side grooves, the measurement of the displacement (front face vs load line), or different conditions during testing (e.g., selection of testing temperatures) are analyzed and discussed.
Buckling Strength of the Liners of Type IV Hydrogen Storage Cylinders
Authors: Feng Heyi , Jiang Yongshan , Bo Ke , Deng Guide , Wu Xiaofei , Yang Hao 
Published: November 2023

Abstract
Type IV hydrogen storage cylinders have the advantages of long fatigue life, high hydrogen storage density, and low cost, which makes it a popular research and development topic. Local buckling phenomena of the cylinder liners are observed during rapid depressurization of the type IV hydrogen storage cylinders. The buckling strength of their liners against external pressure was studied by numerical simulation and vacuum test, and the factors that may influence the buckling strength were investigated by numerical simulation. Three sets of liners with 60 L volume capacity were selected, for which the length-to-diameter ratio was around 2.5. An experiment was performed to study the buckling strength of the liner against external pressure. The test result shows that the buckling strength of the liner is about 0.06 MPa. Finite element analysis shows that the liner used in the experiment has a buckling strength around 0.03 MPa. The reason why the difference occurs may be the leakage of the liner induced by poor sealing technique in the experiment. Finite element analysis was used to conduct a parametric study on factors that may affect the buckling strength, which are left-over weld height and thickness-to-diameter ratio. The FEA results show that the buckling strength of the liner is much smaller than 0.1 MPa. The left-over weld height during the fabrication process slightly increases the buckling strength when thickness is greater than 2 mm, while it does not have a significant effect on buckling mode. The buckling strength of the liner increases with an increasing thickness-to-diameter ratio.
Numerical Simulations of the Dynamic Response of Gas Handling Manifolds Mounted on an Impulsively Loaded Confinement Vessel
Authors: Valdiviez Robert , Spernjak Dusan , Scarafiotti Jesse 
Published: November 2023

Abstract
A new vessel system is being developed for performing small-scale shock-physics experiments in a proton beam imaging facility at the Los Alamos National Laboratory (LANL). The Inner Pressure Confinement Vessel (IPCV) is the impulsively loaded vessel that confines the detonation products from the explosively driven experiment and provides access for the proton beam, and other diagnostics, to interrogate the dynamic event. The products of the detonation, that are either in a gaseous state or a solid state, are confined within the IPCV. The gaseous products are to be vented from the IPCV prior to allowing personnel to reenter the experiment area and be in close proximity to the IPCV.
The IPCV is connected to the overall gas handling system, known as the Vessel Gas Handling System (VGHS) via three independent manifold assemblies. Each manifold is operated remotely to allow for the venting of the gaseous products in the IPCV. Each manifold is rigidly connected to the top cover of the IPCV, and each receives significant dynamic loading from the IPCV performing its impulsively loaded confining function.
The basic design requirement for the VGHS manifolds is to meet the requirements of the standard ASME B31.3, Process Piping. ASME B31.3 in turn allows for analyzing unlisted components to the requirements of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 2, or designated as ASME VIII-2 for the structural response. Each IPCV VGHS manifold assembly is analyzed per ASME VIII-2 for its dynamic loading response because all components are unlisted for this loading regime. This paper reports on the simulation effort performed to predict the structural response of the manifold assemblies to the impulsive loading environment of the IPCV.
Development of Prediction Tool for Flow-Accelerated Corrosion (4) Development and Validation of Prediction Software “FALSET” With Water Single-Phase FAC Data Obtained in Japanese PWR Plants
Authors: Morita Ryo , Uchiyama Yuta , Fujiwara Kazutoshi , Yoneda Kimitoshi 
Published: November 2023

Abstract
Pipe wall thinning is one of the important issues to be managed in the maintenance of power plants. In Japan, as utilities manage wall thinning on the basis of pipe wall thickness measurements, a large number of wall thickness measurements are necessary for each outage in power plants. Therefore, the authors have developed a wall thinning prediction software, “FALSET”, for the improvement of wall thinning management. This report describes details of FALSET, and its validation and modification using Japanese PWR plant data with high-pH operation and all secondary system temperature conditions. The results show that FALSET can evaluate the wall thinning rate that is close to the measured thinning rate of actual Japanese plant, thereby improving the reliability of FALSET.
Study on the Small Leakage Characteristics and Noise Reduction Methods of Liquid Pipelines Based on Internal Acoustic Detection
Authors: Ma YunDong , Dong ShaoHua , Wei Haotian , Qian WeiChao , Zhang Hang , Xu LuShuai 
Published: November 2023

Abstract
Timeously detecting pipeline small leakages caused by corrosion, aging, and crack can critically impact structural safety. However, identifying small leaks is challenging and small leaks can gradually develop into significant leakage problems. Although the negative wave method is currently the most common approach used for pipeline leakage detection, it is limited by the working conditions, length, and diameter of the pipeline and cannot be employed to identify small leaks of less than 1 L per min in pipeline. Therefore, to address this problem, this paper established a technique based on passive acoustic internal detection. This study simulated the variation laws between the leakage rates and sound power levels with different leakage apertures and internal pressures using the Ansys Fluent 19.0 software and performed small leakage detection experiments to verify the feasibility of the finite element simulation method. The findings indicated a positive correlation change in the leakage rates and sound power levels in conjunction with the leakage apertures and internal pressures. Furthermore, a denoising algorithm based on a small leakage of self-encoder was proposed, and a denoising model was introduced for signal. This improved denoising efficiency and reduced the dependence on sample data. The signal-to-noise ratio (SNR) of this algorithm exceeded that of traditional denoising methods, while the root mean square error (RMSE) was lower, verifying its feasibility in denoising. It also provided a research basis for denoising in complex operational environments.
Check Valve Rotor Concept to Form an Imploding Liquid Liner for Magnetized Target Fusion Application
Authors: Dick Jean Sebastien , Bernard Scott , Khalzov Ivan 
Published: November 2023

Abstract
Magnetized Target Fusion (MTF) is an approach to fusion energy generation through the implosion of a liquid metal cavity to compress a deuterium-tritium (D-T) plasma. We propose a method to drive a cavity collapse through direct interaction between the liquid liner with pressurized gas. Our method involves the use of passive check valves to provide a cost-effective and partially reversible process of collapse generation. A subscale cylindrical rotating cavity experiment is designed and constructed to analyze the performance of the concept using pressurized air and a water liner. A high-speed camera and image processing methods are used to identify the trajectory of the free surface of the water liner and identify the impact of rotational speed and gas pressure on the cavity collapse. Experimental data is compared with a simplified dynamic model derived from inviscid Navier-Stokes equations, and two-dimensional axisymmetric computational fluid dynamics (CFD) simulations with the commercial code Ansys Fluent. We see agreement between experiment and both numerical approaches within measurement uncertainty. We discuss how our results will inform the development of larger-scale prototypes.
Vortex Shedding Dynamic in Tandem Circular Cylinders Placed in a Turbulent Crossflow
Authors: Habowski Patrick Batista , Neumeister Roberta Fátima , Möller Sergio Viçosa 
Published: November 2023

Abstract
This article presents an experimental exploration with numerical support of two circular cylinders tandem placed to a turbulent crossflow with L/D ratios of 5, 7.5, 10, and 12.5, where L is the axial distance between the cylinders, and D is the diameter of the cylinder. The force coefficients, flow visualization, and Strouhal numbers were obtained from the numerical simulations. The wake flow velocity and the lateral acceleration of the cylinders were acquired from the experiments. In both studies, a free flow velocity of 10 m/s was imposed, maintaining the Reynolds number in the subcritical flow range, considering the cylinder diameter. Numerical studies employed the gmsh software to generate the mesh and the OpenFOAM software to compute the results. A wind channel with a square cross-section of 1m and two circular slender cylinders were used to obtain the signals of lateral acceleration and wake flow velocity. These signals were post-processed by Matlab software using the wavelet and Fourier analyses. The main conclusions pointed out that the L/D spacing ratio of 5 was the configuration most influenced by the vortex shedding. This was observed in the experimental values of the lateral acceleration and in the numerical results of lift fluctuations. All the proposed L/D spacing ratios presented shear layer reattachment and lateral oscillation caused by the vortex shedding from the upstream cylinder.
Effect of Stress-Strain Curve on Burst Pressure Prediction for Pipelines With and Without Corrosion Defects
Authors: Tao Gang 
Published: November 2023

Abstract
Recent research in remaining burst strength prediction models for corroded pipeline has found that the material strain hardening property (stress-strain curve shape) is crucial for improving the prediction accuracy. The comparison between finite element analysis (FEA) and full-scale burst test results in a recent study also demonstrated strong evidence of the plastic instability failure mechanism for pipe samples with corrosion defects, suggesting that the strain hardening property has a key role in the burst strength of corroded pipes.
In this paper, analytical burst pressure prediction models for pipes with and without corrosion defects are briefly reviewed to illustrate the theoretical basis for including the strain hardening property in the model prediction. A suite of parametric FEA was then conducted on previously tested pipe samples with two different materials to further investigate the effect of the strain hardening property on the burst pressure prediction of corroded pipelines. Based on the test evidence from a recent study, a plastic instability-based failure criterion was proposed for FEA prediction of the burst pressure. The proposed failure criterion was further validated by full-scale burst test results referenced in this study. Based on the FEA burst pressure prediction with the new failure criterion, the effect of the strain hardening property on burst strength of pipe samples with corrosion defects was quantitatively evaluated. Using the parametric FEA results, selected remaining burst strength models were critically examined. The outcome of the model assessment provided a basis for future improvement of these models.
A Novel Strain-Based Fracture Evaluation Method For Long-Distance Pipeline Girth Weld With The Crack Tip Under Large Scale Yield Condition
Authors: Wu Kai , Dong Jie , Guo Guangfei 
Published: November 2023

Abstract
The strain-based failure assessment diagram is an important method to assess the crack defects in the pipeline, especially when the nominal stress of the pipeline exceeds the yield strength of the material. The weld strength matching factor is an important parameter affecting the fracture behavior of the pipeline girth weld, while the traditional strain-based failure assessment diagram method cannot consider the influence of weld strength matching. Given this, a finite element model of the crack driving force for local circumferential cracks on the outer surface of girth welds of pipelines was established by the numerical simulation method. Based on the reference strain calculation method proposed by BS 7910-2019, the effect of crack depth, crack length, weld strength matching factor, and pipe yield strength on the assessment accuracy of SBFAD for pipeline girth weld crack was verified. Based on this, the improved method and calculation model of reference strain is proposed, and the weld strength matching is incorporated into the strain-based failure assessment diagram accurately, which improves the application scope and evaluation accuracy of the BS 7910-2019 evaluation method. The accuracy of the evaluation method is verified by experimental data. The results provide a reference for the engineering critical assessment of pipeline girth welds and also provide technical support for ensuring the intrinsic safety of long-distance steel pipelines.
Safety Assessment of Hydrogen Discharge With Various Types of Vent Exit
Authors: Zhang Chongchong , Feng Heyi , Mu Lijing , Wang Xin , Deng Guide 
Published: November 2023

Abstract
A hydrogen vent is one of the fundamental equipment that ensures safe operation of hydrogen systems. Its venting direction could significantly affect the hydrogen concentration in the surrounding air. As the density of hydrogen is small compared to air, a hydrogen vent is typically installed away from personnel exposure area, which minimizes safety risk during venting process. However, a vent exit with an upward direction has a risk of taking in rainwater. Thus, this article studies the effect of the vent exit directions in hydrogen system from safety perspective; the considered directions are horizontal, vertical downwards, and a miter cut. The analysis was carried out by numerical simulation, in which the effect of discharge speed, wind speed, and nitrogen concentration were considered. The nitrogen concentration was considered because the system may be discharged with nitrogen gas before operation, some left-over nitrogen gas in pipelines may mix with hydrogen at the beginning of system operation. The safety margin in the study was taken as 25% of hydrogen lower explosive limit (LEL), which is 1% volume concentration of hydrogen. The results show that the vertical downwards vent results in the greatest risk distance. In contrast, risk distance is the smallest with horizontal vent. Compared to pure hydrogen discharging, hydrogen-nitrogen mixture gas would increase the risk distance. The distance reaches maximum for horizontal, vertical downwards, and miter cut when the nitrogen concentration is 95%, 75%, and 55%, respectively. The maximum distances are 0.8m, 0.5m, and 0.2m, respectively. It can be observed that the wind speed significantly affects the hydrogen diffusion at the vent exit, in which the increasing amount of vertical downwards vent is greater than horizontal vent at level 1 wind speed (0.3 m/s). The risk distance decreases at level 2 wind speed (1.6 m/s) because the hydrogen concentration is reduced due to diffusion. Among the studied vent exit direction, the horizontal vent has the best overall performance, while vertical downwards vent has the worst overall performance.