bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physics-Informed Data Augmentation of Experimental Erosion Data Through Generative Adversarial Networks
Authors: Zhang Jun , Li Jamie (Yijie) , Pei Weiping , Shirazi Siamack 
Published: September 2024

Abstract
Erosion is a phenomenon of material removal by particles impinging the walls of materials. Experiment is an important approach to investigate erosion severity and the influences of different physical parameters. However, conducting experiments is expensive and time-consuming. It’s also challenging to collect high quality data due to the scales of the material removal and its sensitivity to the change of external environments. Over the years, research has been conducted at the Erosion/Corrosion Research Center at the University of Tulsa to investigate solid particle erosion in pipelines and fittings. The experiments are conducted with a large-scale boom tower flow loop and erosion data is collected with high accuracy temperature compensated ultrasonic transducers. The efforts have resulted in more than 200 sets of high-quality experimental data under various pipe diameters, particle diameters, sand concentrations and flow velocities. Mining the inherent pattern and/or laws within the data is of great value to guide future process condition selections and experimental tests. More importantly, with the existing data that has covered a wide range of flow, particle, pipe size and sand concentration conditions, machine learning methods can be utilized to augment the data itself so that the new generated data obeys the physical laws and have similar distributions. Generative Adversarial Networks (GANs) is a class of machine learning models designed for generating data. It has a broad application. Data augmentation is an area where it can be applied to generate additional training data when data is limited for later machine learning or deep learning. The feature is of significance to expand erosion databank based on a relatively small high-quality database for subsequent mechanistic modeling. This present work shows how to apply GANs to achieve the goal and the newly generated data are validated with both original data and the data obtained through Computational Fluid Dynamics of which physics of unseen conditions are fully simulated and SPPS which is a semi-mechanistic model developed at E/CRC. The work provides engineers and researchers with a new approach to expand databases and build mechanistic models upon it.
Assessing Particle Concentration in the Breathing Zone of a Receptor Mannequin in an Indoor Environment
Authors: Anvari Amirmasoud , Ahmadi Goodarz 
Published: September 2024

Abstract
This study examined the distribution and dispersion of respiratory droplets in a ventilated office space containing two mannequins with a partition between them. It was assumed that one of the mannequins was speaking and emitting respiratory droplets., The transition k-kl-ω turbulence model was employed to analyze the airflow pattern and the dispersion of droplets in the presence of the partition. The ANSYS-Fluent code was used to simulate the airflow conditions in the room. The Lagrangian particle tracking method was used to evaluate the droplet velocity and trajectories in the room. The Discrete Random Walk (DRW) model was used to simulate the effects of turbulence fluctuations on particle dispersion. The airflow conditions for different ventilation flow rates and dispersion of droplets of different sizes emitted by the speaking mannequin were evaluated. In addition, the concentration of droplets of different sizes near the receptor mannequin was evaluated. Furthermore, the distribution of droplets of varying sizes close to the receptor mannequin was evaluated. The droplet concentrations were evaluated using the two-way coupling technique implemented through ANSYS-Fluent code and a MATLAB Code using the Lagrangian particle tracking approach. The concentration results obtained from the Lagrangian approach are compared with those predicted by the enhanced diffusion model.
Fluid Flow Characteristics of Twin and Gerotor Screw Compressors
Authors: Hsieh Chiu-Fan , Cao Yu-Ji , Lin Yi-Hao , Wang Sheng-Yao 
Published: September 2024

Abstract
The study explores variations in fluid flow characteristics between two types of screw compressors: the twin-screw compressor (TSC) and the gerotor screw compressor (GSC). After generating rotor profiles using mathematical models, 3D fluid analysis models for both screw compressors are constructed using computational fluid dynamics (CFD). To facilitate comparison, the cross-sectional areas in the TSC chamber and the outer rotor of the GSC are designed to be the same, with identical area efficiency and screw rotor helix angles. Under consistent design conditions, the study examines three different rotor lengths (120mm, 180mm, and 240mm) for both GSC and TSC to assess the impact of screw compressor design on output performance and compare their flow characteristics. The evaluation includes output mass flow rate, pressure, temperature, and their fluctuation properties to discern the advantages and disadvantages of the two screw compressor designs. Simulation results indicate that increasing the length of the screw compressor enhances the mass flow rate. However, higher lengths lead to power losses and increased leakage, potentially negatively affecting compressor efficiency. Furthermore, the GSC exhibits a higher outlet average pressure compared to the TSC for the same length, with relatively smaller pressure fluctuations in a suitable rotor length. Additionally, the GSC design achieves a lower stable temperature through a smoother compression process. This smoother compression process ensures a steady fluid flow, resulting in reduced friction and stable temperatures. Overall, the GSC demonstrates several advantages, including a higher flow rate, greater operating stability, lower leakage, reduced power loss, and improved efficiency compared to the TSC across all three rotor lengths.
Using Japanese Animation for Fluid Mechanics Education: Examples From “One Punch Man”
Authors: Ryu Sangjin 
Published: September 2024

Abstract
Visual popular culture provides various engaging examples for teaching STEM (science, technology, engineering, and mathematics). As one genre of visual pop culture, Japanese animation, or anime, has steadily gained popularity in the United States. Since anime is not constrained by reality, this separation from reality offers unique opportunities to use anime to teach the key principles of fluid mechanics. I have been using fluid-mechanics-related examples found in anime not only for formal fluid mechanics education but also for informal STEM outreach activities. In this paper, I present examples found in “One Punch Man.” In this anime, Saitama is a superhero who can defeat any monsters and supervillains with a single punch. However, he cannot kill an irritating mosquito although he swats the insect with his hands. I use this scene as an example to explain the flow caused by a moving object due to the no-slip boundary condition and the stagnation point of the caused flow. Then, I recommend Saitama to use a fly swatter based on the aerodynamics of the fly swatter. The aerodynamics of the swatter head is related to the boundary layer and extended toward the olfactory antenna motion of lobsters. Since Japanese animation is widely enjoyed by people around the world, it has rich potential as a source of novel fluid mechanics examples that connect with students’ interests and thus capture their attention.
An Experimental Study on the Sublimation-Induced Porous Structure Formation in a Freezing-Based Inkjet 3D Printing Method
Authors: Zhang Haipeng , Zhang Xiaoxiao , Liu Yang 
Published: September 2024

Abstract
A colloidal solution is a mixture of small insoluble solid particles with a fluid, widely used as ink solutions in inkjet-based 3-dimensional (3D) printing technology. During the printing process, the liquid solvent is removed via subsequent drying processes, such as evaporation, with only solid particles deposited on the substrate. The printed products’ quality and mechanical properties can be harmed when the particle distribution is non-uniform due to the internal flows occurring in a droplet during evaporation. To address this issue, a freezing sublimation-based printing method was developed in recent year to minimize internal flow-related particle motions during the drying process, which can improve the quality of printing. While the colloidal particles were found to be distributed much more uniformly on substrates using the novel freezing sublimation-based method, it was found that colloidal particles could form 3D porous structures on substrates after the solvent was sublimated. In this paper, an experimental study was conducted to evaluate the particle deposition patterns of 15% (w/v) Pearlitol 100 SD Mannitol water solution droplets under different sublimation conditions. The porous structures formed on substrates after sublimation were visualized using microscopy imaging technology. The results obtained from this study showed that pores formed in printed structures are directly related to the escaping gaseous phase from frozen droplets during sublimation. Smaller and fewer pores are formed when the heating rate during sublimation is slower. Therefore, a slow sublimation process is recommended for the freezing sublimation-based inkjet 3D printing method for producing better quality and higher resolution 3D products.
Development of a Novel Stewart Motion Platform for Wind Tunnel Testing of Floating Wind Turbines
Authors: Laisee Laiba , Aguayza Carlos , Carter Shawn , Liu Yang 
Published: September 2024

Abstract
The utilization of offshore floating wind turbines is anticipated as one of the most sustainable sources of renewable energy. The research on these floating wind turbines requires highly sophisticated and established testing facilities that can produce simultaneous aerodynamic and hydrodynamic loadings on the floating turbines. However, due to the scaling mismatch of the airflow, water-flow, and wave profiles in most of the current test facilities, the laboratory testing of floating wind turbines has been very challenging. The primary focus of the present study is to develop a novel method of testing floating wind turbines in regular wind tunnel facilities. In this paper, we aim to develop a new experimental approach of simulating the floating turbine motions induced by ocean waves using Stewart motion platforms. These motion platforms can generate six degrees of freedom and mimic the motions of linear translations and axial rotations found in a multitude of floating devices. In designing the Stewart motion platform, kinematics was used with rotational actuators in translating the platform and developing a wave generation program for general motion displacement. In addition, multiple types of wave formations and their displacements are generated based on a systematic calculation and coordinate conversions of each individual actuator. The motion platform is capable of translating to nearly 5 cm linearly and reaching a maximum rotation of 15 degrees in both directions individually and simultaneously. The prototype platform model in this paper is used for turbine models about 30 cm in height for testing in a large-scale atmospheric wind tunnel facility. This work can be further developed by harnessing machine learning capabilities of data collection from research performed in wave tanks or field testing. Subsequently, in considering the effects of a floater, further research implementations of a floater’s response are dependent on the properties and behavior of a buoyant structure which leads to a closer accurate model of a floating wind turbine in the ocean.
Asymmetric Wind Turbine Blades: Numerical Investigation of Wake Interactions for Rotors With Non-Identical Blade Loadings
Authors: Sarlak Hamid 
Published: September 2024

Abstract
The inner and outer regions of a wind turbine blade, known as the root and tip, produce powerful vortex structures in the helical vortex system that form the near wake region. Over time and space, these large vortex structures break down to smaller-scale turbulence, which characterizes the far-wake region. The presence of perturbation is one of the means to trigger a faster breakdown of the vortex structures. A faster breakdown of the vortices is considered favorable due to the so-called momentum entrainment from the boundary layer that in turn energizes the flow for the downstream turbines to extract more energy. In this research, we will demonstrate the effects of introducing rotor asymmetries in wake development and dynamics of tip vortex interactions in a cluster of two wind in-line turbines. Simulations are performed by representing wind turbine blades using the blade element method (BEM) based actuator line modeling and large eddy simulation (LES) technique is employed to solve the governing Navier-Stokes equations of motion. Our preliminary investigations suggest that introducing an asymmetry in the rotor can alter wake structures and their downstream development, causing a faster transition into the far wake leading to a higher power density.
Passive Suppression of Diffuser Rotating Stall in a Centrifugal Pump by the Non-Symmetry Diffuser Vane
Authors: Takahashi Mikio , Iwasaki Dai , Konno Shinichi , Ejiri Shinichiro , Miyabe Masahiro 
Published: September 2024

Abstract
Diffuser Rotating Stall (DRS), a fluid instability, often restricts the operational range of diffuser-type centrifugal pumps, requiring countermeasures in industry. Despite various proposed methods for DRS suppression, the optimal approach minimizing pump efficiency reduction remains nonexistent.
In this study, we explored a new DRS suppression method by investigating the mechanism when combining long and short vanes in the vaned diffuser of an industrial pump.
The original vaned diffuser has eight long vanes, with short vanes created by removing the leading edge alternately. Varying short vanes from one to three, we studied the phenomena through experiments and Computational Fluid Dynamics (CFD). Experiments used a closed-loop piping system with a centrifugal pump (specific speed Ns = 138 m3/min, m, rpm = 920 USgpm, ft, rpm). Four pressure sensors in the diffuser passage captured DRS behavior. Incremental valve adjustments from high to low flow (minimum ϕ = 0.002) explored pump performance and DRS occurrence.
Results showed DRS at ϕ = 0.048 for the original diffuser shape, absent at higher flow rates and present at lower ones. With a single short vane, DRS occurred at ϕ = 0.058 without circumferential propagation. Increasing short vanes to two or three prevented DRS until ϕ = 0.010, demonstrating non-symmetric vane effectiveness.
Internal flow analysis using CFD software (Unsteady RANS calculation = URANS) explored time evolution within the diffuser and detailed short vane influences on DRS.
Hydrodynamic Interactions in Fish-Like Robotic Swarms With Flexible Propulsors
Authors: Menzer Alec , Lengkong Theodore , Ni Di , Nagpal Radhika , Dong Haibo 
Published: September 2024

Abstract
In this work computational models of Bluebots, bio-inspired swimming robots that demonstrate 3D maneuverability and collective behaviors, are developed. Flexibility is prescribed to the caudal fins (CF) using a virtual skeleton. The hydrodynamic interactions occurring within in-line arrangements of these Bluebots is investigated by altering the flexion angle of the leader Bluebot caudal fin and a balance between optimizing leader Bluebot (LB) performance and follower Bluebot (FB) wake interaction is identified. Compared to the rigid CF baseline, optimal CF flexion for the thrust of LB leads to higher negative pressure within generated vortex structures and narrowing of the thrust jet which impinges along the entire body of the FB. Further increase of the LB flexion creates even stronger negative pressure regions while widening the thrust jet behind the leader. These flow conditions are more favorable for the FB as the accelerated flow only interacts with the anterior of the robot body and the stronger negative pressure supplies stronger anterior suction. The ability of the FB to sense these flow changes is also important, and the pressure sensor data on the FB exhibits differences between the cases. Near the anterior surface, the sensor pressure data provides insight to the varying vortex ring strengths for higher LB CF flexion, meanwhile, such differences are not as obvious when examining probe data further downstream on the FB.
Surface Roughness Effects on the Hypersonic Flow Over Double-Wedge Bodies With a Blunt Leading Edge at Different Aft-Wedge Angles
Authors: Kumar Piyush , Rodriguez Arturo , Adansi Richard O. , Kumar Vinod , Moreno Esperanza , Alonzo Eric M. 
Published: September 2024

Abstract
Recently, blunt bodies have been studied numerically through computational fluid dynamics due to their ability to maintain higher heating loads at hypersonic speeds due to their heat distribution on a larger volume than their counterparts: sharp bodies. For this study, we have simulated a blunt double-wedge geometry using different fluid flow models, such as turbulence models: k-omega and laminar, to be compared against varying levels of surface roughness. Additionally, we compare the sharp cone with the aforementioned leading-blunt edge bodies, both with double wedges, at varying degrees of surface roughness. We then find that a leading blunt edge can alter the shock interaction pattern compared to its sharp geometrical counterpart. We aim to study aerothermal heating under different conditions without incorporating the ablation effects during hypersonic flight for extended periods that depend on the Mach Number. This study approximates the aero-thermal heating the double-cone wedge geometry will experience under different hypersonic speeds on turbulent fluid flow regimes and surface roughness values. We know that turbulent fluid flow will create higher aero-thermal heating and drag than laminar fluid flow. We estimate transition effects on the double wedge blunt geometry by comparing the laminar and turbulent fluid flow regimes. This paper will explicitly provide those values from computational fluid dynamics studies. We have performed benchmark studies and have compared our studies against literature values against other geometries.
Sustainable Building Energy Modeling: the Synergistic Interplay of Urban Heat Island, Heat Waves, and Climate Zones
Authors: Najian Maede , Goudarzi Navid 
Published: September 2024

Abstract
This study explores the impact of climate phenomena and their interactions on evaluating building energy analysis. The Urban Heat Island (UHI) is highlighted as a key parameter affecting the microclimate around buildings, influencing energy consumption, and thermal comfort. This study also examines other relevant factors such as Heat Waves (HWs) and their interaction with UHI and climate zones. Employing the Weather Research Forecasting (WRF) model and statistical analyses, the research focuses on Singapore and Australia to investigate the relationships between UHI, HW, and climate zones. Our findings indicated that climate zones and the frequency of climate phenomena play a pivotal role in determining the impact of HW on UHI. Although HWs had a limited effect on UHI in Singapore, data from Sydney showed varied UHI responses to HWs. Understanding these complex interactions is crucial for designing high-performance buildings and improving building energy modeling tools.
Experimental Investigation of Water Droplet Erosion on Metallic and Non-Metallic Materials
Authors: Anderson Keldon , Azimy Noushin , Lichty Emmelia , Karimi Soroor 
Published: September 2024

Abstract
Water droplet erosion (WDE) is a complex phenomenon that has been investigated for nearly a century. This form of erosion affects a wide range of energy industries from steam turbines and natural gas pipelines to wind turbine blades. The moving droplets impacting at a high relative speed create a high surge in surface pressure on the impacted material and damage the surface. The damage removes materials and can compromise strength for steam turbines and pipelines or affect the lift and drag forces on wind turbine blades. Research on WDE has been ongoing for decades with a majority of the reported results focused on metallic material testing and qualitative analysis comparing methodologies or surface conditions. The ongoing research at The University of Tulsa is conducting experiments with a variety of materials while exposed to an environment where water droplet erosion occurs. Impact velocity and droplet sizes are controlled within the facility and ongoing research with particle image velocimetry (PIV) is in use to characterize the falling droplets. Stainless steel 316, Aluminum 6061, and a variety of non-metallic materials are tested for a variety of conditions. The mass of each specimen is tracked and recorded at set intervals to determine the erosion ratio and erosion rate. Various other factors such as flowrate and rotational velocity are determined before testing as well as the percentage of droplets which impact the surface is determined with the use of a highspeed camera. Scanning electron microscopy (SEM) is also utilized to examine the material’s surfaces before and after testing to investigate the severity of erosion by water droplets. One impact velocity and one impact angle are set for all tested materials. These data points will be the starting point for future tests and modeling work to predict water droplet erosion based on simple factors.
Spin Coating on Freeform Surfaces: A Numerical Study
Authors: Shan Yujie , Mao Huachao 
Published: September 2024

Abstract
Spin coating on flat substrates is a well-understood fluid phenomenon, creating uniform thin films with microscale and nanoscale thicknesses. It is widely used in the microscale and nanoscale fabrication of functional devices. Beyond flat substrates, there is an increasing manufacturing demand for fabricating micro/nanoscale thin films on non-flat substrates, such as spherical and freefrom surfaces. However, it is still challenging to model spin coating on a non-flat substrate. This paper numerically models the spin coating on a freeform substrate as a laminar flow. The centrifugal force from spinning was modeled as a volume force proportional to the spin coating speed square and radius. Various initial thicknesses were simulated and compared. A two-way sinusoidal surface was used as the freeform surface. The simulation results showed that the coating thickness converged to an asymptotic solution, regardless of the initial coating conditions. Also, similar to the spin coating on a flat surface, we found the thickness of the spin coating on a non-flat surface was halved when the spin coating time was increased to four times. These surprising results produce a predictable thin film coating on the freeform surfaces, which enables microfabrication on the freeform substrate.
Influence of Simulation Box Sizes on the Stability of Lysozyme Dimers and Hexamers in a Crystallization Solution
Authors: Kordonskaya Yu. V. , Garipov I. F. , Timofeev V. I. , Marchenkova M. A. , Dyakova Yu. A. , Pisarevsky Yu. V. , Kovalchuk M. V. 
Published: September 2024

Abstract
The effect of the simulation box size on the stability of lysozyme dimers and hexamers formed in its solution before crystallization is studied by molecular dynamics. The behavior of these oligomers in boxes of different sizes is simulated, and their stability is assessed. It is shown that increasing the simulation box does not lead to refinement of the simulation results. The dimer stability weakly depends on the box sizes, while hexamers dissociated in all boxes considered, which is consistent with small-angle scattering data. The minimum distance between the protein and the box edge, at which the results of modeling oligomer behavior in crystallization solutions are reliable, is determined (1 nm).