bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Study of Ammonia/O2-Fired Semiclosed Cycle Gas Turbine for Oxy-Fuel IGCC Power Generation With CO2 Capture
Authors: Hasegawa Takeharu 
Published: February 2021

Abstract
With an increase in renewable energy generation, thermal power generation has been switched to standby power in various parts of the world. Ammonia, one of the storage and transport media for H2, is produced in a highly efficient oxyfuel integrated coal gasification combined cycle (IGCC) system with CO2 capture, for the future hydrogen-using society. Using ammonia as an industrial raw material, agricultural fertilizer, and transportation fuel, energy systems can be established by combining renewable energy and thermal power generation. Therefore, it is possible to simultaneously construct a thermal power supply system suitable for backup power source owing to the fluctuation of the renewable power generation and to improve the availability of the thermal power plant and the load-leveling. This will serve as an incentive to build a future zero-emission thermal power plant. In this study, an oxy-fuel IGCC power generation coproduced with ammonia and CO2 capture is conceptually proposed. Furthermore, the features and challenges of a gas turbine that fuels CO2-free NH3 are investigated. In particular, the combustion exhaust characteristics of ammonia/oxygen-fired semiclosed cycle gas turbine combustor in comparison with those of the conventional fuels are characterized through a kinetic analysis.
Torsional Vibration Extraction of Dual-Period Instantaneous Angular Speed Measurement of the Generalized Incremental Encoder
Authors: Zhang Yuhao , Gu Yujiong , Zhao Pengcheng , Chen Dongchao , Yang Kun 
Published: February 2021

Abstract
Torsional vibration is key information in monitoring the condition of the shaft system. Using the vector superposition principle, the relationship between the rotation motion and the torsional vibration of the shaft is analyzed. This paper proposes a generalized incremental encoder model and constructs a piecewise function to describe the principle of the pulse output type speed measuring device. The incremental encoder uses a fixed angular increment to stamp the time component of the angular motion of the shaft, thereby establishing a discrete relationship between the angular motion of the shaft and the time component. The relationship between the angular resolution of the encoder and the torsional vibration signal sampling theorem is deduced. The asymmetric under-sampling of the torsional vibration signals is explained from the perspective of signal sampling. According to the index period invariance of the reconstruction of the encoder disk angle sequence, a dual-period instantaneous angular speed (IAS) calculation method is proposed, which uses all the time stamps, avoiding the sampling bandwidth idle caused by the single-period method, causing the torsional vibration signal to obtain more detailed information, and its analysis bandwidth is twice that of the single-period method. Simulation and experiment verified the correctness and superiority of the research content. Finally, the calculation method was packaged as a functional module and embedded in an online torsional vibration monitoring device applied to two 1000 Mw nuclear power turbine generator sets.
Experimental Investigation Into the Role of Mean Flame Stabilization on the Combustion Dynamics of High-Hydrogen Fuels in a Turbulent Combustor
Authors: Baraiya Nikhil A. , Ramanan Vikram , Baladandayuthapani N. , Vegad Chetankumar S. , Chakravarthy S. R. 
Published: February 2021

Abstract
A bluff-body turbulent combustor is mapped for its thermo-acoustic stability across variation in airflow rate, nondimensionalized as the Reynolds number (Re) and fuel composition. The combustor stability is evaluated for three fuels, namely, pure hydrogen (PH), synthesis natural gas (SNG), and syngas (SG). The combustion dynamics display markedly different behavior across the fuels, in the extent of the unstable region, as well as the observed dominant Eigenvalues. At low Re, SNG displays stable combustion, while SG exhibits high amplitude oscillations at the fundamental duct acoustic mode. As the Re is increased, SNG displays very high amplitude oscillations at the duct acoustic mode, while SG exhibit relatively low amplitude oscillations at the third harmonic. In the case of PH, high amplitude oscillations observed at higher Re at the first harmonic. These peculiarities are investigated in light of the role of mean flame stabilization. The combustion dynamics of the fuels is influenced by the global equivalence ratio, as well as the jet momentum ratio. These effects significantly demarcate the dynamics of SNG and SG combustion. This is seen manifested in the mean flame structure of flame at high amplitude oscillations, whereby result in SNG flame to be present in the wake, while the SG flame resides in the shear layer. The driving by the flame because of their mean stabilization is quantified by a spatial Rayleigh index. It confirms the presence of large driving regions for SNG compared to that of SG, results in the observed differences in amplitude of the oscillations.
Measurement Drift in 3-Hole Yaw Pressure Probes From 5µm Sand Fouling at 1050 °C
Authors: Turner Edward J. , Bogdan Matthew F. , O’Connell Tyler M. , Ng Wing F. , Lowe Kevin T. , Crook Loren , Stevenson Richard , Roberts James 
Published: February 2021

AbstractThe present paper focuses on the resilience of 3-hole pressure probes to hot sand fouling in turbomachinery environments. These probes are utilized inside jet engine hot sections for diagnostics and flow characterization. Ingestion of sand and other particulates pose a significant risk to hot section components and measurement devices in gas turbine engines. In this study, wedge, cylindrical, and trapezoidal probes were exposed to hot section turbine aerothermal conditions of 1050 °C and 65–70 m/s flow velocity and fouled with 0–5 µm Arizona Road Dust (ARD). Sand accumulated more rapidly on the surface of the trapezoidal and cylindrical probe geometries than on the surface of the wedge probe geometry. Probe calibrations following sand fouling were performed in an ambient temperature, open air, calibration jet at Mach 0.3 and 0.5. Calibration curves using nondimensional coefficients were used to assess probe error in yaw angle due to sand fouling. Probe error was based on each probe’s ability to accurately measure flow direction over a flow angle range of [−10 deg, 10 deg]. On average, the probes displayed greater error at Mach 0.5 than Mach 0.3. The wedge probe performed the best after sand fouling and displayed a maximum error of less than ±2 deg in yaw angle. In contrast, the cylindrical probe performed the worst after sand fouling and displayed maximum errors of more than ±8 deg in yaw angle. Transient response did not change notably with sand fouling.
Barriers for Industrial Sensor Integration Design—An Exploratory Interview Study
Authors: Juul-Nyholm Herle Bagh , Ebro Martin , Eifler Tobias 
Published: February 2021

Abstract
The transition to Industry 4.0 poses new challenges for sensor integration design. The foundation of any intelligent system is the data, and the data quality depends largely on the integration of the sensor generating it. In this study, the barriers for robust sensor system design are explored through an interview study among practitioners from different industrial contexts. The aim is to explore potential challenges within different contexts and suggest possible directions for research within the field of sensor integration design. Beyond the question of new sensing technologies, the study highlights an increasing challenge of physical integration tasks and illustrates the varying requirements for development support in different industry sectors.
An Investigation in the Numerical Approach to Solve the Heat Transfer Phenomenon in Gas Turbine
Authors: Kumar Sourabh , Amano Ryoichi S. 
Published: February 2021

Abstract
The gas turbine engine's extreme conditions need a robust design to produce efficient energy and for reliable operation. Flow and thermal analysis are essential for complex aerodynamic and thermodynamic interaction during turbine performance. There is a need to understand and predict the temperature to make the gas turbine engine efficient. This paper will outline the numerical methods applied for primary cooling methods in gas turbine blades. These include impinging leading-edge cooling, internal cooling in the midsection, and pin fin in the trailing edge. The main objective of this paper is to understand the numerical research done on improving gas turbine cooling. The emphasis will be on understanding the present computational fluid dynamics (CFD) techniques applied for gas turbine cooling and further development. This paper briefly outlines the new conjugate heat transfer–based CFD modeling techniques that have evolved over the years due to recent computing power development.
Net Zero Energy Model for Wastewater Treatment Plants
Authors: Qandil Mohammad D. , Abbas Ahmad I. , Salem Abdel Rahman , Abdelhadi Ahmad I. , Hasan Alaa , Nourin Farah Nazifa , Abousabae Mohamed , Selim Osama M. , Espindola Juan , Amano Ryoichi S. 
Published: February 2021

Abstract
The primary objective of this study is to achieve net-zero energy (NZE) wastewater treatment plants (WWTPs) by utilizing energy efficiency opportunities (EEO), combined heat and power (CHP) systems, and other renewable energy (RE) sources, e.g., solar, water, and wind powers. This study discusses an innovative energy solution for WWTPs in the United States, and one of the WWTPs with a flow capacity of 1.5 million gallons per day (MGD) was selected as a case study. An optimization tool, Hybrid Optimization of Multiple Energy Resources (HOMER) software, is used in this study to find the best energy system configuration to run the system. An energy audit for one WWTP was conducted in early 2020 and the report is used to do this study. The proposed EEOs were able to reduce WWTP energy consumption by about 11%. The excess anaerobic digester gas was utilized in a CHP system to cover about 42% of the facility’s consumption. Also, 3% of the utility energy consumption can be claimed by microturbines in the aeration tanks. Another two renewable energy systems, solar photovoltaic (PV) with 29% and water turbines with 15%, contribute to covering 100% of the WWTP energy consumption and achieving an NZE WWTP.
Information Exchange Patterns in Digital Engineering: An Observational Study Using Web-Based Virtual Design Studio
Authors: Thekinen Joseph , Grogan Paul T. 
Published: February 2021

Abstract
This paper performs an observational human subjects study to investigate how design teams use an information system to exchange, store, and synthesize information in an engineering design task. Framed through the lens of decision-based design, a surrogate design task models an aircraft design problem with 12 design parameters across four roles and six system-level functional requirements. A virtual design studio provides a browser-based interface for four participants in a 30-min design session. Data collected across 10 design sessions provide process factors about communication patterns and outcome factors about the resulting design. Correlation analysis shows a positive relationship between design iteration and outcome performance but a negative relationship between chat messages and outcome performance. Discussion explains how advances in information exchange, storage, and synthesis can support future design activities.
Quantification of the Complex Crack Geometry Effect on Fracture Resistance Using Strain-Based Finite Element Damage Analysis
Authors: Kim Seung-Jae , Ryu Ho-Wan , Kim Jin-Weon , Oh Young-Jin , Kim Yun-Jae 
Published: February 2021

Abstract
This paper examines the effect of complex crack geometry on the J-resistance curves obtained by strain-based ductile tearing simulation of complex cracked tension (CC(T)) specimens. The damage model is determined by analyzing the results of a smooth bar tensile test and a compact tension (C(T)) specimen toughness test on an SA508 Gr.1a low-alloy steel at 316 °C. The validity of the damage model and simulation method is checked by comparing the fracture test data for two CC(T) specimen tests. To investigate the effect of the complex crack geometry on the crack growth profiles and J-resistance curves, two geometric parameters (namely, the through-wall crack length and the surface crack depth) are systematically varied. It is found that the J-resistance curves for the CC(T) specimens with various through-wall crack lengths and surface crack depths are consistently lower than the corresponding 1 T C(T) J-resistance curves. The effect of the through-wall crack length upon the J-resistance curve is found to be less significant than that of the surface crack depth. Moreover, the J-resistance curve decreases continuously with increasing surface crack depth.
A Mobility Determination Method for Parallel Platforms Based on the Lie Algebra of SE(3) and Its Subspaces
Authors: Sánchez-García A. J. , Rico J. M. , Cervantes-Sánchez J. J. , López-Custodio P. C. 
Published: February 2021

Abstract
This contribution presents a screw theory-based method for determining the mobility of fully parallel platforms. The method is based on the application of three stages. The first stage involves the application of the intersection of subalgebras of Lie algebra, se(3), of the special Euclidean group, SE(3), associated with the legs of the platform. The second stage analyzes the possibility of the legs of the platform generating a sum or direct sum of two subalgebras of the Lie algebra, se(3). The last stage, if necessary, considers the possibility of the kinematic pairs of the legs satisfying certain velocity conditions; these conditions reduce the platform’s mobility analysis to one that can be solved using one of the two previous stages. Several examples are illustrated.
Dynamic Simulation-Guided Design of Tumbling Magnetic Microrobots
Authors: Xie Jiayin , Bi Chenghao , Cappelleri David J. , Chakraborty Nilanjan 
Published: February 2021

Abstract
The design of robots at the small scale is a trial-and-error based process, which is costly and time-consuming. There are few dynamic simulation tools available to accurately predict the motion or performance of untethered microrobots as they move over a substrate. At smaller length scales, the influence of adhesion and friction, which scales with surface area, becomes more pronounced. Thus, rigid body dynamic simulators, which implicitly assume that contact between two bodies can be modeled as point contact, are not suitable. In this paper, we present techniques for simulating the motion of microrobots where there can be intermittent and non-point contact between the robot and the substrate. We use these techniques to study the motion of tumbling microrobots of different shapes and select shapes that are optimal for improving locomotion performance. Simulation results are verified using experimental data on linear velocity, maximum climbable incline angle, and microrobot trajectory. Microrobots with improved geometry were fabricated, but limitations in the fabrication process resulted in unexpected manufacturing errors and material/size scale adjustments. The developed simulation model can incorporate these limitations and emulate their effect on the microrobot’s motion, reproducing the experimental behavior of the tumbling microrobots, further showcasing the effectiveness of having such a dynamic model.
Prototype Human Model for the Evaluation of a Crew Transportation Module
Authors: Evans D. , Jayaram U. , Jayaram S. , Angster S. , Pettit R. 
Published: February 2021

Abstract
This paper details the design and implementation of a prototype human model for use in evaluation of a Crew Transportation Module for a Reusable Launch Vehicle design. This human model allows the user to use a combination of immersive and non-immersive techniques for ergonomic evaluations. The human model presented in this paper has the following functionalities: free floating (each body part is uninfluenced by other body parts), scalable (the parametric nature allows for scaling of each individual body part), calibration of body parts (to account for error in the mounting of the tracking devices to the body parts), gripping methods, multiple body part tracking configurations, predefined sitting and standing postures, mouse-based manipulation of human model, and dynamic switching between first and third person views. The overall goal was to create a scaleable human model software system which could be easily included in any immersive or non-immersive graphics application. This human model was inserted into a MuSE™-based environment. The methods used to create this human model and its salient features as well as its shortcomings are discussed in this paper.
Numerical Simulation of Viscous Flow-Field in Cascade Using Thin-Layer Equations and AF Method
Authors: Xiao Yumin , Amano R. S. 
Published: February 2021

Abstract
In this paper an implicit 3-D solver for computations of a viscous flow has been developed and the computations of the flow between blade passage are presented. This method employs an AF (Approximate Factorization) method in which four techniques are incorporated to speed up convergence to the steady-state solutions: (1) body-fitted H-grid; (2) artificial viscosity; (3) implicit residual smoothing; and (4) local time-stepping. The two-dimensional pseudo-characteristic method was used to determine the inlet and outlet boundary conditions of the computational domain and the periodic boundary conditions were used at inter-boards. The validation cases include subsonic and transonic viscous flows in C3X cascade. Results for these turbine cascade flows are presented and compared with experiments at corresponding conditions. Computed pressure distributions on blade surfaces show good agreement with the published experimental data. This method was further applied to a three-dimensional case and demonstrated the code capability for predicting the secondary flow in a 3-D transonic flow-field. From these computations it was found that the proposed method possesses superior convergence characteristics and can be extended to unsteady flow calculations. Finally, it was observed that the three-dimensional calculation results show that the secondary flow mechanism in a transonic cascade seems to be quit different from those, in a subsonic case.
Slurry Residue Removal in Post Chemical Mechanical Polishing
Authors: Busnaina Ahmed A. , Moumen Naim 
Published: February 2021

Abstract
The megasonic cleaning process proved to be an essential process in cleaning silicon wafers after processes such as pre-oxidation, pre-CVD, pre-EPI, post-ASH and lately post-CMP. Current post-CMP cleans are contact cleaning techniques. These contact techniques have a low throughput and may cause wafer scratching. In addition, in contact cleaning, brush shedding which occurs under many operating conditions causes additional particulate contamination. There is a need for an effective post-CMP cleaning process. Megasonic cleaning provides the best alternative or compliment to brush clean.
Determination of Propane-Air Maximum Mixing Times
Authors: Brasoveanu Dan , Gupta Ashwani K. 
Published: February 2021

Abstract
The model of gaseous fuel and air mixing, developed by the authors2–3, is applied here to calculate maximum mixing times of propane and air. The degree of mixing is determined using the mass fraction of fuel while the rate of mixing is determined from the rate of this mass fraction. The values of both these parameters are local, i.e., measured within an infinitesimal element of fluid. An Eulerian representation is used. The model is based on the assumption that both fuel and air behaves like single chemical species. It is further assumed that pressure is low and only fuel and air are present within the fluid element. Under non-reacting conditions, the model is valid anywhere in the combustor. Under reacting conditions, the model is valid within those combustor regions where the fuel-air mixture is not flammable. The results of this analysis show that mixing times of propane and air are most reduced by high gradients of temperature and velocity, as long as these gradients act in phase. To a lesser degree, high gradients of pressure also help reduce mixing times. High initial pressure and temperature increase mixing time. Mixing with air penetration into the fuel flow is slower than with propane dispersion into the surrounding air. In general, the exact mixing time has to be determined numerically. Nevertheless, the analytical solutions included here provide maximum mixing times of propane and air under most conditions. These results provide important guidelines for the development of high intensity, high efficiency and low emission combustors.
Basic Models in Fire Development
Authors: Kim Hyeong-Jin , Lilley David G. 
Published: February 2021

Abstract
The ultimate goal of this study is to improve scientific understanding of fire behavior leading to flashover in structural fires. This document summarizes important information in five topic areas: burning rates, radiant ignition, fire spread rates, ventilation limit imposed by size of opening, and flashover criteria.
These are the main components related to the scientific understanding of the fire growth and flashover problem involved in real-world structural fires. Within each topic area, there are four subsections dealing with background, theory, comments, and references. Main components of the study are to develop improved mathematical simulations so as to improve the accuracy of theoretical calculation and to develop and extend the range of knowledge and modeling capability so as to extend the range of available experimental data.
Pool Fires and Radiant Ignition Capability
Authors: Lilley David G. 
Published: February 2021

Abstract
Radiation heat transfer is a primary reason for fire growth. Experimental data are needed to clarify the ignition potential and time required to ignite a particular “target” second item. The objective of the present contribution is to clarify how the size and material of a pool fire determine ignition distance capability, and exemplify realistic calculations related to real-world situations.
Constrained Kalman Filter in Structural Model Identification
Authors: Yang Y. , Zhang H. , Foliente G. C. , Ma F. 
Published: February 2021

Abstract
In this paper, a constrained Kaiman filter is developed for the purpose of estimating the parameters of nonlinear structural hysteresis model. In this method, a constrained method is incorporated into the extended Kalman filter to develop convergence stability, precision and speed. At the same time, a global weighted iteration technique is used to tackle the problem of arbitrary initial values. It can be found that this method is highly efficient in identification of inelastic structures from both clean data and noise-corrupted data.