bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shear-Induced Lift Force on Micro-Fiber Deposition in Low Reynolds Number Flows
Authors: Tian Lin , Li Jiang , Ahmadi Goodarz , Delgado-Gutiérrez Arturo Javier 
Published: September 2024

Abstract
Shear-induced lift lateral migration significantly affects fiber deposition in wall-bounded flows. In the absence of active physical transport mechanisms, the contribution of the shear-induced lift could become the driving deposition force. Due to technical difficulties, investigation into this phenomenon has been limited, and its implication on particle deposition has not been fully understood. This study explored the effect of shear-induced lift and rotation on micro-fiber transport and deposition in low Reynolds number flows. Transport and deposition of non-neutrally buoyant ellipsoidal fibers in Poiseuille flow in horizontal and vertical ducts are examined numerically, and various lateral migration scenarios are investigated. It was found that, in the absence of sideway gravity, shear-induced lift and rotation cause the fibers to drift across the flow streamlines in a vertical channel. This lateral movement is the driving force for fiber deposition in downward flows or moves. In contrast, the particles move toward the channel center in an upward flow configuration. The lateral migration velocity in the vertical channel correlates positively with fiber length and shear rate. The lateral migration in a horizontal duct is comparatively small, where the sideway gravity is dominant. The current study identified the flow scenarios where the lateral migration driven by the shear-induced lift is the dominant contributing factor for deposition and, therefore, should not be neglected.
Investigation of the Influence of Tubercles on the Operating and Cavitation Behavior of an Axial Pump
Authors: Rinnert Tobias , Beck David , Thamsen Paul Uwe 
Published: September 2024

Abstract
Previous investigations have already shown the delay of flow separation at critical angles of attack as an effect of tubercles on the flow around airfoils both, numerically and experimentally. However, concerning axial pump impellers, the knowledge about the influence of tubercle modification along the leading edge is not yet sufficient. Therefore, the aim of this investigation is to understand the influence of a sinusoidal tubercle leading edge geometry on the operating behavior as well as the cavitation behavior of an axial pump using numerical and experimental methods. For this purpose, an unmodified reference impeller with a Gö11K profile is designed, which serves as the basis for the impeller modified with tubercles. Using a steady-state simulation, the characteristics of each impeller are investigated. The operating behavior of both impellers is then investigated on a test rig according to EN ISO 9906. The experimental investigations lead to the finding that the presented tubercle modification causes a reduction of the head at part load and an increase at overload. Furthermore, the experiments show that the tubercle modification increases maximum efficiency. The experimental investigation of the cavitation behavior of both impellers shows that the introduced tubercle modification generally leads to the onset of cavitation-induced head drop at significantly lower NPSH values, thus improving the cavitation behavior.
Numerical Investigation of the Performance Curve Instability of a Centrifugal Pump With Vaned Diffusers
Authors: Baum Andreas , Böhle Martin 
Published: September 2024

Abstract
Centrifugal pumps equipped with vaned diffusers of specific speed nq ≥ 30 ([min−1, m3 s−1, m]) are prone to performance curve instability at part-load. The present paper deals with the numerical comparison between a middle stage of a multi stage centrifugal pump equiped with a vaned diffuser (nq ≈ 35 ([min−1, m3 s−1, m]) and a vaneless diffuser respectively. For the simulations the SAS-SST turbulence model has been used. While in the vaneless case a distinct head drop does not exist, a local dent appears for the vaned diffuser at approximately 60% of the design flow rate. With the onset of the instability, pressure generation shows extensive fluctuations between different revolutions. Besides classic performance evaluation, static pressure generation is analysed at the diffuser to characterize responsible sections for the head drop. Furthermore, the progression of the axial force shows distinct differences among both configurations. The results show, that highly transient flow detachment and vortex structures in the inlet triangle section at the diffuser vane suction side and the hub occur. These vortex structures lead to increased losses in the inlet trianglular section and induce recirculation zones at the impeller outlet. Thus, inferences can be drawn between pattern switching phenomenon and axial force of the pump.
Experimental Investigation of Electrically Actuated Control Valves for GLCC© Operation
Authors: Awofuwa Daniel O. , Mohan Ram S. , Shoham Ovadia , Kolla Srinivas Swaroop , Lobo Mark 
Published: September 2024

Abstract
The Gas-Liquid Cylindrical Cyclone (GLCC©) is an outstanding compact separator known for its efficient separation of gas-liquid mixtures and compact design. To ensure high separation efficiency, it is important to mitigate one of two unwanted phenomena known as Gas-Carry-Under (GCU) at the outlet of the GLCC which in part is achieved by implementing adequate control configurations downstream of the GLCC. These control configurations regulate the liquid level ensuring efficient separation in the GLCC and have been deployed in the industry for different field applications. In this project, the active control configuration is applied to explore the limits of the electrically actuated Atlas Severe Service control valves installed in the gas and liquid legs of the GLCC at various flow conditions, aimed to improve the GLCC separation efficiency.
The main objective of this study was to acquire data on two-phase (namely air-mineral oil, air-water) and three-phase flow (air-mineral-oil-water) exploring the effects of control valve response time and fluid composition on GCU. Furthermore, the acquired data were compared with similar empirical data from pneumatically actuated control valves in conjunction with the GLCC. All this was accomplished by modifying the existing GLCC test section of the 4-phase TUSTP experimental flow loop at the University of Tulsa equipped with a state-of-the-art data acquisition system.
Analysis of the experimental data shows that the GCU is greater for air-mineral oil flow conditions as compared with air-water. In addition, the data shows that GCU decreases with an increase in the superficial liquid velocity for both two-phase and three-phase flow conditions. The data acquired using the Atlas Severe Service control valves showed higher GCU for both two and three-phase flow across various flow conditions when compared with similar data for the existing pneumatically actuated control valves. This in part is owing to the lag time in response between the Atlas Severe Service valve synchronous motor actuator and the Helical bevel gear-drive control valves. The implementation of a fast-acting servomotor actuator to the Atlas Severe Service control valve configuration could mitigate GCU and improve the overall separation efficiency of the GLCC.
A Comprehensive Study for Defining the Uncertainty of Erosion Simulations
Authors: Fallah Shojaie Elham , Hasan Mubashir , Darihaki Farzin , Karimi Soroor , Shirazi Siamack A. 
Published: September 2024

Abstract
Uncertainties are part of any scientific measurements and calculations. As a complex phenomenon, erosion is affected by many independent parameters and consequently the uncertainties of these parameters contribute to uncertainties in erosion measurements or simulations/predictions. Erosion experiments are costly and time consuming, hence other means must be used to obtain erosion values. Computational Fluid Dynamics (CFD) codes are excellent tools in simulating flow and are used for solid particle erosion calculations for industrial applications for which measured data are unavailable. One of the most utilized frameworks for uncertainty estimation of simulations is ASME standard of Validation and Verification (ASME V&V). According to this standard, there are three main elements of uncertainties in any simulation; input, numerical, and modeling. The modeling element is heavily influenced by the results of measurements, i.e. the measured data and the corresponding uncertainties. In this research, ASME’s guideline is utilized for estimating erosion uncertainty for cases with and without data available. Two alternatives are introduced to be used as replacements for cases where data is not available. These alternatives are machine learning predictions and erosion correlations both developed based on significant number of experiments. The database used in this study includes experimental data with air-sand flows in 3 and 4-inch elbows conducted with 75, 150, and 300-μm sand particles. Finally, the estimated bounds of uncertainties are compared with those obtained by measurements. These comparisons show good agreement between the estimated and measured bounds of uncertainties.
Dynamics of Bubble Growth and Collapse Under Pressure Perturbation
Authors: Isazadeh Amin , Bhaduri Sreetam , Ziviani Davide , Claridge David E. 
Published: September 2024

Abstract
This study investigates the dynamic response of deformable particles to pressure perturbations, utilizing analytical and numerical analyses. Numerical simulations using Fluent software explore the impact of internal pressure deviations, step changes, and oscillations in ambient pressure across a wide size range. The study uncovers systematic and damped oscillatory responses to pressure deviations, highlighting the significance of liquid viscosity and surface tension in determining equilibrium states. Particle size emerges as a key factor, influencing equilibrium pressures, dynamic responses, and power spectral characteristics. Findings include smaller particles exhibiting higher equilibrium pressures and longer stabilization times. Power Spectral Density (PSD) analysis reveals a consistent dominant frequency, with smaller particles displaying higher peak frequencies. Analytical exploration emphasizes the roles of surface tension, viscosity, temperature, and mean ambient pressure in shaping peak frequency and deformation magnitude. The analysis shows smaller particle size have larger peak frequency, but smaller deformation. Moreover, raising surface tension leads to a wider range of particle sizes whose peak frequencies are not zero.
Determination of the Equivalent Rotordynamic Coefficients and Leakage of a T-Type Labyrinth Seal
Authors: Ashraf Muhammad Mubashar , Untaroiu Alexandrina 
Published: September 2024

Abstract
Rotating machinery requires adequate sealing to reducing the secondary leakage between high-pressure and low-pressure regions and in turn improve efficiency. Different types of annular gas seals are used for multiple turbomachinery applications. This includes finger, leaf, brush (for more specialized applications), hole and honeycomb patterned seals. In comparison to other configurations, labyrinth seals are most commonly used due to their high robustness and low manufacturing costs in rotating machinery applications. The recently introduced T-type labyrinth seal has the potential to reduce the fluid-induced excitations in the aero-engines in comparison to conventional ones. Seal clearance from the rotor surface plays an important role in the performance and efficiency of the seal in terms of rotor dynamics and leakage rate. Therefore, a parametric analysis is required to determine the optimal clearance which not only reduces the leakage but also minimizes the overall contribution to the vibration of the system. It is known that the T-type seals have T shape teeth which provide a greater increase in the inward radial aerodynamic force. This inward force is due to the enhanced Lomakin effect of the seal flow field. The earlier research has shown that the leakage of T-type labyrinth seal is approximately 23.6% to 25.3% less than the straight through (i.e., conventional) labyrinth seals by keeping the same tip clearance and axial length for the seal. This paper focuses on the sensitivity analysis using the design of experiments (DOE) along with the steady-state computational fluid dynamics (CFD) to determine the optimum tip clearance for the reduced leakage rate of a T-type labyrinth seal. Since the fluid-induced excitations play a significant role in the rotordynamic system, equivalent rotordynamic coefficients are extracted using steady-state CFD simulation based on the circular whirl orbit and perturbation analysis, where the small perturbation is applied to the rotor, which is generally 10% of the seal clearance. In this study, conventional labyrinth seal is numerically modelled, and then verified through test results existing in the literature. In addition, the numerical results are compared with existing simulation results in literature. The effective damping of conventional and T-type labyrinth seals is also calculated using the equivalent rotordynamic coefficients. The previous research on the T-type seals is used for benchmarking and validation of the analysis.
Exploring Capillary Flow in Paper-Based Microfluidics: Unraveling Mechanics and Applications
Authors: Moreno Esperanza , Kumar Piyush , Adansi Richard O. , Rodriguez Arturo , Kumar Vinod 
Published: September 2024

Abstract
The present paper is a comprehensive exploration of the intricate mechanics and applications of capillary-driven flow, specifically delving into the wicking phenomenon within the realm of paper-based microfluidics. The study employs extensive numerical simulations to unravel the dynamics of liquid wicking within a paper strip, with a keen focus on key parameters such as porosity, permeability, capillary radius, surface tension, and viscosity. The accuracy of the simulation model is rigorously validated against the Lucas-Washburn equation, thereby establishing a robust foundation for insights crucial to the optimization of microfluidic devices. The research emphasizes the paramount importance of parameter control in achieving specific capillary rise behaviors. Significant observations include the augmentation of capillary rise with higher surface tension, evident in the pronounced meniscus, and the facilitating role of larger, well-connected pores and higher porosity in promoting increased capillary rise. Furthermore, the study explores the interplay between viscosity and cohesive forces, revealing that higher viscosity strengthens cohesive forces while diminishing surface tension, thus influencing capillary rise. These findings collectively advance the understanding of paper-based microfluidics, offering a robust foundation for practical applications in diverse domains. From healthcare diagnostics to environmental monitoring and quality assessment in the food industry, the research contributes valuable knowledge to the evolving field of microfluidic technology.
A Machine-Learned Actuator Line Model for Hydrokinetic Turbines
Authors: Bowman Joshua , Bhushan Shanti , Burgreen Greg , Dettwiller Ian 
Published: September 2024

Abstract
This study introduces a machine-learned actuator Line model (ML-ALM) for hydrokinetic turbines to enhance computational fluid dynamics (CFD) simulations of turbine wakes and performance. By integrating machine learning with the actuator line model (ALM), the ML-ALM seeks to accurately replicate the complex wake interactions and turbine performances observed in high-fidelity blade-resolved models while maintaining computational efficiency. Utilizing OpenFOAM simulations and data from blade-resolved models, the ML-ALM is trained to predict the forces exerted by the turbine blades under various flow conditions. This novel approach is validated against experimental data and traditional CFD models, demonstrating its potential to improve energy extraction efficiency and optimize turbine array configurations. The ML-ALM represents a significant advancement in hydrokinetic turbine modeling, balancing high-fidelity models’ accuracy and lower-fidelity models’ efficiency. This study not only contributes to the field of renewable energy by enhancing turbine simulation techniques but also showcases the applicability of machine learning in complex engineering systems.
Upwind Collocation Meshless Method for the Discrete Lattice Boltzmann Equation in Fluid Simulations
Authors: Maidenberg Amandine , Divo Eduardo , Chen Leitao 
Published: September 2024

Abstract
Discrete Boltzmann Equation (DBE) has gained attention in recent years for its ability to efficiently simulate flows that require details at both the micro and macro scales. Often in Computational Fluid Dynamics there is a tradeoff between computational expense and computational accuracy, and so a method that can simulate multiscale fluid flows accurately while also being efficient, has much to offer. Traditionally, the DBE had been limited by grided domain modeling, however emerging meshless methods are being used to address more complex geometries. In this paper, the stability of the DBE solved by the Locally Collocated Radial Basis Function Meshless Method (LCMM) is considered in the simulation of Taylor Green Vortex (TGV) flow. An alternative upwinding scheme in LCMM is proposed and demonstrated to have improved stability, without loss of accuracy.
Fundamental Study of Development of Flow Visualization System Using Ultrasonic Velocity Profiler and Augmented Reality
Authors: Namiki Yutaka , Shoji Naruki , Kikura Hiroshige 
Published: September 2024

Abstract
In Japan, where the energy supply structure is fragile, maintaining the safety of nuclear power plants is a top priority. In plants, flow in the piping causes defects and wall thinning. For that reason, nondestructive inspection and early detection of abnormalities in piping in power plants are required to ensure safety. Therefore, the objective of this study is to develop a flow visualization system to improve safety in plants. As a piping inspection method, we focused on UVP (Ultrasonic Velocity Profiler) due to its non-invasiveness, high measurement accuracy, and measurement applicability. The UVP device is characterized by its portability, which makes it highly compatible with Augmented Reality (AR) technology. The developed system visualizes the flow field by superimposing an image of the flow field created based on data obtained by the UVP method and an image of the measurement position taken by a camera. This system was used to visualize and measure the flow in a circular tube and the Kalman vortex flow. As a result, the accuracy of the image projection position and the reproducibility of the flow field were confirmed, demonstrating the effectiveness of this system.
Simulation of Forced and Mixed Convection Heat Transfer in Vertical Pipes
Authors: Dzodzo Milorad B. 
Published: September 2024

Abstract
Forced and mixed convection-generated velocity and temperature fields in vertical pipes containing liquid metals and water were numerically predicted with a computational fluid dynamics model based on a finite volume method. The constant heat flux is imposed as a boundary condition at walls. The developed model considers the variable properties of liquid metals. The range of considered Reynolds and modified Grashof numbers is 10,000 &lt; Re &lt; 50,000 and 108 &lt; Gr* &lt; 4 * 108. The ascending and descending flows with moderate and high buoyancy were considered. Various sensitivity studies such as mesh sizes, and meshing approaches, considered computational domains, various initial, inlet, and outlet conditions, and effects of axial conduction in walls were performed. The meshing approach was based on hexahedral cells and local mesh refinement near the walls. To evaluate various modeling approaches the similarities and differences between predictions and available experimental results were presented and discussed based on the comparisons of the velocity and temperature profiles and Nusselt number.
mSphere of Influence: When a sequencer is more than a sequencer
Authors: Billmyre R. Blake 
Published: September 2024

ABSTRACT

Blake Billmyre uses functional genomics to help understand the biology of fungal pathogens, with an emphasis on evolution of virulence relevant traits and drug resistance. In this mSphere of Influence article, he reflects on how two papers (Liachko et al., “High-resolution mapping, characterization, and optimization of autonomously replicating sequences in yeast,” Genome Research, 2013, and Guo et al., “Integration profiling of gene function with dense maps of transposon integration,” Genetics, 2013) impacted his research trajectory and goals. These articles show the power of creative use of sequencing as a tool to drive understanding of fundamental biology.
An exploratory investigation of heart rate and heart rate variability responses to daylong heat exposure in young and older adults
Authors: Carrillo Andres E. , Meade Robert D. , Herry Christophe L. , Seely Andrew J.E. , Kenny Glen P. 
Published: September 2024

Heart rate variability (HRV) has shown potential as a tool for monitoring thermal strain, but there is limited data to support its efficacy in older adults during prolonged heat exposures. We compared HRV between young (19–31 years, n = 20) and older (61–78 years, n = 39) adults during 9 h of heat exposure (40 °C, 9% RH). We also explored whether heart rate (HR) and/or HRV could be used to distinguish older adults who achieved elevated thermal strain, defined as either (1) an increase in core temperature >1.0 °C (occurring in 39%, 15/39) or (2) a reduction in systolic blood pressure >10 mm Hg (occurring in 67%, 26/39). Percentage of age-predicted maximal HR and percentage of heart rate reserve (HRR) were higher, whereas standard deviation of normal RR intervals, the square root of the mean of squared differences between successive RR intervals (RMSSD), high frequency power (HF), and cardiac vagal index (CVI) were lower in older compared to young adults during heat exposure ( P ≤ 0.004). In older adults, increases in core temperature were correlated with percentage of age-predicted maximal HR, percentage of HRR, RMSSD, and CVI ( P ≤ 0.031), whereas changes in systolic blood pressure were not significantly associated with HR or HRV indices ( P ≥ 0.327). Receiver operating characteristic curve analysis indicated that HR and HRV indices had generally poor ability to identify older adults with elevated thermal strain (area under the curve ≤0.65). Age-related differences in HRV, consistent with vagal withdrawal among older adults, remained during daylong heat exposure, but marked heterogeneity of response likely contributed to HRV providing limited discriminatory value in identifying changes in core temperature or blood pressure in older adults.
New mechanism for fermion localization in the presence of anti-curvature tensor
Authors: Moreira A. R. P. , Dong Shi-Hai , Ahmed F. 
Published: September 2024

AbstractThis study aims into brane-world scenarios within the framework of f(R, A) gravity called Ricci-inverse modified theory, exploring the dynamics of spin-1/2 fermions coupled non-minimally to background scalar field functions. Through theoretical analysis and numerical techniques, we investigate the localization of both massless and massive fermionic modes on the brane. Our findings shows intricate phenomena, including unexpected configurations of the effective potentials and the identification of resonance modes in massive fermionic spectra. These insights shed light on the interplay between modified gravity and matter in extra-dimensional models, offering promising avenues for experimental validation and furthering our understanding of fundamental physics.