bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Numerical Simulation of Transitional and Turbulent Flows Over Multi-Scale Surface Roughness - Part II: The Effect of Roughness on the Performance of a High-Pressure Turbine Blade
Authors: Nardini Massimiliano , Jelly Thomas O. , Kozul Melissa , Sandberg Richard D. , Vitt Paul , Sluyter Greg 
Published: September 2023

Abstract
Turbine blades generally present surface roughness introduced in the manufacturing process or caused by in-service degradation, which can have a significant impact on aero-thermal performance. A better understanding of the fundamental physical mechanisms arising from the interaction between the roughness and the turbine flow at engine-relevant conditions can provide insights for the design of blades with improved efficiency and longer operational life. To this end, a high-fidelity numerical framework combining a well-validated solver for Direct Numerical Simulation and a second-order accurate immersed boundary method is employed to predict roughness-induced aero-thermal effects on an LS89 high-pressure turbine (HPT) blade at engine-relevant conditions. Different amplitudes and distributions of surface roughness are investigated and a reference smooth-blade simulation under the same flow conditions is conducted for comparison. Roughness of increasing amplitude progressively shifts the blade suction side boundary layer transition upstream, producing larger values of the turbulent kinetic energy and higher total wake losses. The on-surface data-capturing capabilities of the numerical framework provide direct measurements of the heat flux and the skin friction coefficient, hence offering quantitative information between the surface topology and engineering-relevant performance parameters. This work may provide a benchmark for future numerical studies of turbomachinery flows with roughness.
Flame Transfer Function and Emissions of a Piloted Single Jet Burner: Influence of Hydrogen Content
Authors: zur Nedden Philipp Maximilian , Eck Mattias Ettore Giulio , Lückoff Finn , Panek Lukasz , Orchini Alessandro , Paschereit Christian Oliver 
Published: September 2023

Abstract
The next generation of gas turbines must enable partial or pure hydrogen combustion to decarbonize electricity production. In this respect, jet burners have received increased attention in research and industry as a viable solution for combustors functioning over a wide operational range, as they are well-suited for stabilizing flames with high propagation speeds. In this work, a generic piloted single-jet hydrogen burner is developed and characterized experimentally. The jet burner is operated under lean and dry conditions to keep NOx emissions low. These operating conditions are generally prone to thermoacoustic instabilities. The flame shape, NOx emissions, and the acoustic response of the flame are characterized while varying the hydrogen concentration and the strength of a pilot injection stage. The measurements of the emissions demonstrate that the jet burner is well suited for the combustion of natural gas blends and pure hydrogen with low NOx. The mean flame OH* chemiluminescence images display a decreasing flame length with increasing hydrogen share and a strong dependence on the pilot strength. Last, the heat release rate response is assessed based on measured flame transfer functions for different fuel blends. We demonstrate that the injector used in this study is non-stiff. To assess the stiffness of the injector, a full flame transfer matrix is measured for selected cases, and a comparison of the two methods is provided.
Compressible Large Eddy Simulation of Thermoacoustic Instabilities in the PRECCINSTA Combustor Using Flamelet Generated Manifolds With Dynamic Thickened Flame Model
Authors: Gövert Simon , Lipkowicz Jonathan Timo , Janus Bertram 
Published: September 2023

Abstract
The fully compressible, density-based CFD-solver TRACE has been extended for simulations of turbulent reacting flows in aero engine gas turbine combustors. The flamelet generated manifolds combustion model is utilized to account for detailed chemical kinetics and combined with the dynamically thickened flame model to resolve the flame front on the large eddy simulation (LES) mesh. The chemistry tabulation is coupled with the LES solver by inversion of the transported energy equation using tabulated mixture averaged NASA polynomial coefficients. LES of the PRECCINSTA test case, a lean, partially-premixed swirl combustor are performed and the two distinctive regimes are correctly predicted: a stable regime with a ‘quite’ stable flame and an unstable regime with an oscillating flame driven by self-excited thermoacoustic instabilities. Statistics collected from the simulations, mean and root-mean-square values, are in good agreement with the experimental reference data for both operating conditions. The dominant frequency of the unstable flame deviates from the measurement by about 100 Hz and requires further investigation. The results demonstrate the general suitability of the simulation framework for reacting flow simulations in gas turbine combustion systems and the prediction of self-excited thermoacoustic oscillations.
Transonic Compressor Darmstadt Open Test Case: Experimental Investigation of Stator Secondary Flows and Hub Leakage
Authors: Klausmann Fabian , Kilian Nicklas , He Xiao , Franke Daniel , Schmidt Benedikt , Schiffer Heinz-Peter 
Published: September 2023

Abstract
The future trend of clean sky aviation has led to a smaller core engine, resulting in highly loaded stages with increased relative tip gaps and leakage flows, which causes a reinforced influence of secondary flow phenomena. This paper experimentally investigates the secondary flow effects in the 3D-optimized shrouded stator of the TUDa-GLR-OpenStage, representative of a transonic high-pressure compressor front stage, and its susceptibility to typical hub leakage flows. The impact of stator hub leakage on efficiency and total pressure ratio is investigated for several operating speeds, from subsonic to nominal transonic operating conditions. Steady five-hole probe and time-resolved virtual multi-hole probe measurements at different operating conditions at nominal speed are conducted to investigate the underlying loss mechanisms. The leakage mass flow is determined using the measured pressure difference within the fin seal. Steady results show that the optimized 3D stator effectively suppresses the hub corner separation compared to the predecessor 2D stator, but its performance is further limited by a near-tip separation. With the increased stator hub leakage (at a leakage-to-main flow ratio of about 0.4%), the compressor isentropic efficiency generally drops (by about −0.5%) at the full operating range due to an enhanced hub corner separation effect. However, the increased leakage also helps alleviate the tip-corner separation when operating near stall, leading to a smaller efficiency penalty under these conditions. Unsteady results reveal the sensitivity of transient compressor performance to the passing rotor wake, but limited interaction between this phenomenon and the increased leakage is observed. These findings provide insight into the stator hub leakage-related penalties on the compressor aerodynamics efficiency.
Advanced Hydrogen Cycles to Help Decarbonize the Aviation Industry. Part 1: Development of Simulation & Modeling Toolsets
Authors: Tacconi Jacopo , Grech Nicholas 
Published: September 2023

Abstract
Hydrogen has been identified as a key fuel to enable decarbonization of fundamentally challenging industrial sectors such as the aviation industry. However, the poor volumetric energy density of this element imposes severe challenges on in-flight energy storage when it is directly employed as a fuel. This becomes particularly relevant for high payload, middle-to-long range missions, typical of regional and long-haul markets, where the combination of fuel burned plus reserves represents a large fraction of the total aircraft weight. While storing hydrogen as a high-pressure gas (GH2) is an option, liquid hydrogen (LH2) is a more likely storage solution to be adopted by the aviation industry for these aircraft classes, despite the additional fuel conditioning complexity introduced.
Consequently, having the ability of modeling the whole hydrogen fuel delivery system within the preliminary gas turbine cycle design environment becomes essential. This allows to assess the cycle-level impact imposed by the fuel delivery pressure and temperature requirements at the combustor interface, explore the onboard heat sink potential offered by cryogenic LH2, and better support the future product definition. In Part 1, this paper covers fundamental aspects of hydrogen cycle simulations by discussing the implementation of a preliminary engine design tool, developed in NPSS (Numerical Propulsion System Simulation), which includes the ability to simulate hydrogen fuel properties from its liquid storage state to the engine combustor. Part 2 will explore the application of this model to support the performance evaluation of more advanced hydrogen cycles, only briefly introduced here.
Experiments on Tuned UHBR Open-Test-Case Fan ECL5/CATANA: Performance and Aerodynamics
Authors: Schneider Alexandra P. , Fiquet Anne-Lise , Paoletti Benoit , Ottavy Xavier , Brandstetter Christoph 
Published: September 2023

Abstract
With the advancement of modern fan architectures the lack of experimental benchmarks for the research community became apparent in the recent years. Enormous effort in method development could not be validated on representative geometries and motivated the development of the open-test-case ECL5/CATANA. A carbon fibre fan stage has been designed by Ecole Centrale de Lyon and shared with the community in 2021. The fan is representative of a modern Ultra High Bypass Ratio (UHBR) architecture with sonic design speed. The reference configuration has been investigated experimentally on a novel test facility with multi-physical instrumentation. In this publication the results of the first experimental campaign are presented with a detailed analysis of the aerodynamic performance and system symmetry. The presented results comprise full stage mappings across the whole operating range for three main speedlines (55%, 80% and 100%) using performance rakes, unsteady wall-pressure arrays, tip-clearance and stagger-angle measurements. Radial profiles of intake boundary layer and rotor-exit conditions at selected conditions complete the full validation dataset for steady and unsteady aerodynamic simulations. Results are discussed in comparison to blind-test RANS simulations of different international institutes. Significant predicition inaccuracies of the tip flow and corner separations of the stator are observed and reveal the requirement of real-blade-geometry measurements at running conditions. This paper is accompanied by a publication with a focus on aeroelastic instabilities observed near the stability limit. The results represent a comprehensive dimensional benchmark dataset and allow method validation on multiple levels of fidelity for the aerodynamic and aeroelastic research community.
Comparative Study of the Flow and Thermal Characteristics of Non-Stochastic Lattice and Bio-Inspired Multi-Scale Structures for Gas Turbine Engine Applications
Authors: Sarabhai Shivangi , Velivela Pavan Tejaswi , Zhao Yaoyao Fiona , Sanchez Fabian , Kibsey Mitch 
Published: September 2023

Abstract
Metal Additive Manufacturing has presented gas turbine designers with additional design tools such as cellular solids. However, there is limited research on the early selection of these structures and how these structures interact with flows. Lattice structures are known for their capability to be tailored for achieving specific properties such as high porosity and strength, impact energy absorption, and light-weighting. A literature survey has shown that the mechanical performance of the strut-based and surface-based lattice structures has already been investigated in the past. However, very little research has been conducted to investigate their flow and heat transfer performance, especially for strut-based lattice structures. This research systematically investigates the friction factor and convective heat transfer (CHT) coefficient across strut and surface-based lattice structures. Results show that the complex shape of the Triply Periodic Minimal Surface (TPMS) lattice structure topologies give the flow a better capability to mix and recirculate for convection at the expense of a significant pressure drop. However, topologies with less pressure drop/friction factor and high convective heat transfer coefficient are more suitable for gas turbine engines. Furthermore, this paper investigates the use of newly developed multifunctional bio-inspired design method called as Domain Integrated Design (DID) for an innovative concept to achieve low pressure drop and high effective heat transfer. Comparative study shows that bio-inspired designs have achieved low friction factor as compared to the lattice structures whereas TPMS structures shows better convective heat transfer performance.
Solving Renewable Intermittency With Low-Cost Legacy Turbines Firing 100% Hydrogen: An Ecosystem Analysis
Authors: Gramatikas George , Otto Marcel 
Published: September 2023

Abstract
This paper investigates 100%-hydrogen-fuel gas turbines as an enabler for renewable electric power. Intermittent renewables such as solar and wind raise grid problems and impose commercial power limits. Gas turbines running on 100% hydrogen can be the carbon-free grid-supporting and backing infrastructure. Gas turbines of legacy design are offered new from original equipment manufacturers or refurbished by aftermarket companies and can burn 100% hydrogen today. In this repurposing, fuel efficiency is tertiary to greenhouse gas-free emissions and operational reliability.
Current government incentives in the U.S. market promote converting gas turbines to use hydrogen, the necessary combustion conversion technology, and the large-scale hydrogen production required to achieve $1/kg hydrogen to support those turbines.
Unlike legacy gas turbines, newer high-efficiency advanced-class gas turbines pose more significant flame control challenges like flashback and auto-ignition on hydrogen. This study recognizes the difficulty and possibilities of fueling advanced gas turbines with 100% hydrogen. It compares the cost of efficiency loss, water, and ammonia with the benefit of lower greenhouse gas emissions and on-demand power in all generations of gas turbines.
The study identifies the role and viability of legacy gas turbines as a significant building block in a decarbonization strategy that includes the co-location of solar or wind and vast supplies of clean hydrogen with the goal of grid stability, energy security, and affordability.
Validation of Rotating Detonation Combustor CFD for Predicting Unsteady Supersonic-Subsonic Flow Field at the Exit
Authors: Raj Piyush , Talukdar Shaon , Langner Dalton , Gupta Apurav , Meadows Joseph , Agrawal Ajay 
Published: September 2023

Abstract
Rotating detonation combustors (RDC) have gained increased interest for integration with power-generating gas turbines due to the potential to increase thermal efficiency. The unsteady flow field exiting the RDC is fundamentally different compared to traditional swirl-stabilized combustors. Successful integration of RDC with gas turbines will depend on the ability to properly condition the unsteady flow to achieve performance levels comparable to swirl-stabilized combustors. RDC simulations require significant computational resources due to the small spatial and temporal time scales required to resolve the detonation phenomenon. Furthermore, traditional steady-state computational fluid dynamics (CFD) analyses are not possible for RDC simulations. The present study develops and validates a computationally efficient approach for predicting unsteady flow fields exiting the combustor using 2D, transient reacting CFD with periodic boundary conditions in the combustor and a downstream plenum. Validation is performed by comparing the CFD results to various experimental measurements: i) wave speed obtained from high-speed ion probe and dynamic pressure data, ii) average wall static pressure measurements, and iii) time-resolved particle image velocimetry (PIV) at 100 kHz at the RDC exit. Results indicate good agreement between CFD and experiments with respect to velocity field exiting the RDC, detonation wave speed, and static pressure distribution.
Alignment and Error Analysis to Improve Overlay Accuracy in Roll-to-Roll Screen Printing
Authors: Kim Daehyeon , Kim Youngjin , Kim Hyeongrae , Kim Juyeon , Kang Jongmo , Oh Dongho 
Published: September 2023

Abstract
Products with printed electronics technology can be easily found around us. It is a technology used in various fields such as RFID, flexible displays, and solar panels. Such products feature multi-layer structures rather than using a single pattern layer for printing. A product with excellent performance can be obtained only when overlay printing is performed well in a multi-layer structure. Therefore, to improve overlay accuracy, the effect of film deformation should be considered and compensated. However, deformation of the film is caused by tension applied to the film or heat during the drying process. In this paper, the deformation of the film is compensated by analyzing the register error after printing in the screen overlay printing process, one of the roll-to-roll process technologies. The tendency of film deformation is compensated by measuring the register error by comparing the reference register mark with the additional overprinted register mark, and analyzing the repetitive register error that occurs during overprinting. And it is verified that the overlay accuracy is improved through screen printing to which this compensation system is applied.
Sustainable Analysis of Energy Consumption and Surface Quality of Monocrystalline Silicon in Diamond Wire Sawing
Authors: Sefene Eyob Messele , Chen Chao-Chang Arthur , Wang Steve Hsueh-Ming 
Published: September 2023

Abstract
Semiconductor industries have strong demands for innovative techniques and optimum parameters in the machining domain to minimize the cost and environmental footprint during the wafer fabrication process. Identifying where energy is consumed in a machine tool is a critical step in reducing the energy and environmental impact of machining. In the semiconductor industry, diamond wire sawing (DWS) is a primary and time-consuming wafer fabrication process. However, the evaluation and assessment of energy consumption and carbon dioxide (CO2) emission in this process have not been thoroughly studied. This paper investigates the optimum process parameters for monocrystalline silicon to minimize energy consumption, CO2 emission, and surface quality through the DWS process. The experiment has conducted on rectangular monocrystalline silicon with different process parameters. The energy consumption of the DWS tool at various power sources and the surface roughness of the as-sawn wafers are measured, whereas the CO2 emission of materials and energy consumption of the DWS tool are analyzed. An autoregressive integrated moving average (ARIMA) is employed to predict the energy consumption of the DWS tool. The result indicates that the maximum energy consumption and CO2 emission have been obtained at the higher wire speed and feed rate settings. Besides, the ARIMA model of total energy consumption prediction accuracy reached 99.1% compared to experimental results and verified the developed model.
A 3D Convolutional Neural Networks-Based Model for High-Resolution Prediction and Compensation of Geometrical Errors of Additive Manufactured Parts
Authors: Standfield Benjamin , Kong Zhenyu (James) 
Published: September 2023

Abstract
In this work, 3D convolutional neural networks (CNNs) are developed and utilized to predict and compensate for geometrical errors of parts printed in an FDM process with a resolution of 100 microns. The proposed approach improves additively manufactured part quality by predicting the geometrical error of the parts and then compensating for it by altering the initial geometries, namely, the stereolithography (STL) files, accordingly. It increased the prediction and compensation resolution of voxel-based ML methods to 100 microns, thereby reducing the error associated with each voxel. This is accomplished by leveraging semantic segmentation, a technique traditionally used in image processing for classification, in the domain of 3D voxels. This approach alleviates the computational requirements impeding previous literature, and the methodology becomes a classification problem. Using the F1 measure, a common classification metric in literature, an F1 measure of 0.96 is obtained for an object printed using compensation compared to 0.76 when compensation is not used, demonstrating our proposed method’s effectiveness.
Does Role Identity Mediate the Influence of Motivational Regulations on Physical Activity Behavior Among People 55 Years or Older?
Authors: Amireault Steve , Huffman Mary Katherine 
Published: September 2023

The objective of this study was to estimate the extent to which motivational regulations influence physical activity behavior through role identity among people 55 years or older. Participants (N = 409; Mage = 66.29 years [SD = 7.06]) completed online questionnaires to measure motivational regulations, role identity, and the frequency of physical activity in a typical week and in the past month. Mediation analysis using ordinary least squares path analysis revealed that autonomous forms of motivational regulation (positively) and controlled forms of motivational regulation (negatively) influenced role identity, which then positively influenced physical activity behavior. Bootstrap confidence intervals (95%) for the indirect effects (a × b) based on 5,000 bootstrap samples were entirely above or below zero. These findings point to future experimental evaluations of interventions aiming at both increasing and decreasing autonomous and controlled motivational regulations, respectively, to promote physical activity behavior through role identity.
r
Citrus
BBC: a bacterial resource to mine for new agricultural probiotics for citrus
Authors: Solaz-Rodenas Lucía , Penyalver Ramón 
Published: September 2023

ABSTRACT
A culture collection of 147 selected bacteria from the rhizospheric citrus microbiome is available at the Valencian Institute of Agricultural Research (València, Spain). The data include information on plant growth-promoting (PGP) traits published to date and the presence of PGP-related genes in the available genomes of the different bacterial species.
Genome sequence of
Mesorhizobium mediterraneum
strain R31, a nitrogen-fixing rhizobium used as an inoculant for chickpea in Argentina
Authors: Foresto Emiliano , Revale Santiago , Nievas Fiorela , Carezzano María Evangelina , Puente Mariana , Alzari Pedro , Martinez Mariano , Ben-Assaya Mathilde , Mornico Damien , Santoro Maricel , Martinez-Abarca Francisco , Giordano Walter , Bogino Pablo 
Published: September 2023

ABSTRACT

Here, we report the complete genome sequence of
Mesorhizobium mediterraneum
R31, a rhizobial strain recommended and used as a commercial inoculant for chickpea in Argentina. The genome consists of 7.25 Mb, distributed into four circular replicons: a chromosome of 6.72 Mbp and three plasmids of 0.29, 0.17, and 0.07 Mbp.
An improved
Lodderomyces elongisporus
NRRL YB-4239 genome assembly substantiated by its electrophoretic karyotype
Authors: Hoyer Lois L. , Hogan Elizabeth K. , Freeman Brian A. , Walden Kimberly K. O. , Hernández Alvaro G. 
Published: September 2023

ABSTRACT

Pacific Biosciences long-read sequencing was used to improve the genome assembly for
Lodderomyces elongisporus
strain NRRL YB-4239 (ATCC 11503). The new assembly included eight chromosomes that were substantiated by the electrophoretic karyotype. The nuclear genome was 16.1 Mb (37.2% GC) with 5,740 genes predicted.