bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the Stage Efficiency of Axial Compressors by Vane Rotation
Authors: Ajith Pisharam Akhila , Raja Vijayanandh , Raji Arul Prakash , Madasamy Senthil Kumar 
Published: February 2024

Abstract
There are currently many methods to overcome axial compressor stall. This phenomenon affects the compressor rotor at a great level and hence is of much concern. One method is to control the rotor tip clearance by certain criteria. No rotor tip clearance is ideal, but the general clearance is two millimeters. But modifying the rotor tip clearance requires changes at the design level and is difficult if planned to implement on an already functional model. Hence, a new method is being proposed to improve the stage efficiency and to increase the performance under adverse conditions. This research proposes to give selected stator vanes the capability to rotate by 360 degrees. This rotation shall be normal to the direction of incoming airflow, i.e., axial. The concept of variable stator vanes is currently being used in axial compressors to delay the stall onset and to streamline the flow direction. The mechanism mentioned here will follow a similar purpose with similar principles. The research provides computational results of the same. First, using moving reference frame, the rotation is simulated, and the velocity profile is found to increase. Next, using transient state with moving mesh, the entire stator is designed and selected blades from that are rotated to prove the effectiveness of the method. The velocity and pressure variations are analyzed to identify the effectiveness of this method. The materials’ reaction to these modifications in the operation procedure is also determined. Hence, it is found that the rotation of the stator vanes will provide the necessary momentum for the air to not stall and to maintain the airflow at a speed that is not ideal with a lower mass flow rate, but enough to prevent the air from stalling.
A Strategic Design Approach for Future Fuselage BLI Engine Based Hybrid Propulsion Engine
Authors: Mistry Chetan S. , Kolhe Surendra Kiran , Raj Harsh , Bharade Aditya , Anantwar Jay , Mandal Goutam , Agrawal Abhishek 
Published: February 2024

Abstract
This research paper presents the systematic design approach for a hybrid electric propulsion system using the concept of fuselage BLI (Boundary Layer Ingestion). Various BLI configurations were explored and a rear mounted axisymmetric configuration for the BLI engine was chosen for present study. CFM56-7B24 engine was selected as the baseline engine and the performance of the engine was replicated using the GasTurb 14 software. GasTurb electric module was used to integrate an electric propulsion system with the gas turbine engine and detailed parametric studies for the newly proposed engine were conducted to optimize important performance parameters. The amount of power to be extracted from the primary (underwing) engines to run the BLI fan on the design point was decided by a systematic trade-off study between the net TSFC and the mass of the electric propulsion system, where net TSFC is defined as the ratio of total fuel consumed and the sum of thrusts generated by the primary engines and the aft-body BLI fan. A significant decrease in net TSFC was observed at the design point. To meet the high efficiencies and power requirement, HEMM (High-Efficiency Megawatt Motor) was chosen for running the electric fan. GasTurb’s inbuilt feature was used for estimation of weight for the newly configured engine. A simple mission was generated to compare the performance of the baseline engine with the newly proposed engine and to analyse the performance maps of compressors and turbines. The operating line for the simple mission was plotted over the maps of compressor and turbine to assess their performance throughout the mission. The newly proposed engine was then simulated at off-design conditions in GasTurb. An impressive 13% fuel benefit was observed due to the incorporation of BLI and hybrid operation compared to the baseline engine. This study demonstrates the feasibility of a hybrid electric propulsion system using BLI and provides insights into the design and manufacturing of individual components. The results obtained can thus serve as a valuable reference for future studies in the field of hybrid aircraft propulsion systems.
Effect of Pivot-Shape Modification on Part Clearance Flow Field in Variable Area Turbine Nozzle Vane
Authors: Mandal Goutam , Bhavsar Hardikkumar , Mistry Chetan S. 
Published: February 2024

Abstract
The aim of the study is to investigate and mitigate the secondary losses in a variable turbine area nozzle vane by modifying its pivot shape. The variable area nozzle vane (VANT) is used to actively control the mass flow rate and improve the off-design performance of the turbine stages. However, the clearance required for the pivot mechanism introduces tip leakage losses, which can render the benefits of the variable area nozzle vane useless.
The study uses the 2nd stage of low-pressure turbine vane from the Energy Efficient Engine proposed by Pratt and Whitney. The vane passage is modified to implement the VANT concept, and the effect of different pivot profiles and modifications on the bottom surface near the suction side is investigated at various setting angles. The numerical simulations are performed using Ansys ICEM CFD® and ANSYS CFX®, and the results are analyzed using parameters such as non-dimensional vorticity, static entropy, and total pressure loss coefficient.
The study shows that the improvement upon introduction of shape modifications to the pivot, a) elliptical passage in pivot b) tapered pivot, reduces the total pressure loss coefficient by 4% as compared to the vane passage with unmodified circular pivot. The interaction between the leakage flow and the main passage flow is also observed using three dimensional streamlines. Overall, the study provides insights into the sources of secondary losses in variable turbine area nozzle vanes and demonstrates that modifying the geometrical shape can help mitigate these losses and improve the efficiency of the turbine.
Computational Investigations of Effect of Reynolds Number on Secondary Losses and Flow Behavior in Linear Turbine Cascade
Authors: Darji Anand P. , Baloni Beena D. , Mistry Chetan S. 
Published: February 2024

Abstract
Secondary losses in modern gas turbines are one of the challenging factors among turbine designers and manufacturers which significantly impact the overall gas turbine performance. This study is aimed to provide an insight of the mechanism underlying the secondary loss contribution with the variation of Reynolds Numbers. Firstly, the baseline secondary flow losses are investigated for the 2nd stage low-pressure turbine (LPT) vane root profile of the energy efficient engine (E3) developed by Pratt & Whitney using numerical simulations. Then, the effect of various vane exit Reynolds Numbers ranging from 0.7 × 105 to 6 × 105 on the end wall secondary losses are investigated. The results indicate that the total pressure loss of the linear turbine vane cascade increases with the lower operating Reynolds Number. At higher Reynolds number, the passage vortex and wall-vortex induced by passage vortex shows span-wise extension and limits the passage extension which results in lower secondary loss. Compared to the baseline case, the study showed an increase of approximately 1.5 times for Re = 0.7 × 105 and a reduction of 4% for Re = 6 × 105 in the total pressure loss coefficient at the measured plane downstream of the trailing edge.
New Tip for More Efficient and Less Environmental Impact Gas Flaring Process
Authors: Kamel Ahmed H. , Alzahabi Ahmed , Romero Yazmin 
Published: February 2024

Abstract
The oil and gas industry is constantly evolving, aiming at producing more energy at lower cost with fewer emissions and minimum impacts on the environment. One of the main sources of emission is gas flaring.
Gas flaring involves burning off excess gases using a flare stack, that is a critical piece of equipment designed to release and burn gases and other materials from pressure-relief and vapor-depressurizing systems safely and efficiently. Flares and their mechanical components should be designed to operate properly and reliably for considerably extended periods under specified service conditions. The combustion process occurs through a diffusion flame, which may produce smoke if there is a lack of oxygen and/or carbon particles cool below their ignition temperature. The primary difference between flares is their ability to mix flared gas with oxygen.
Gas flaring is one of the most controversial and challenging environmental problems faced today regionally and globally. Gas flaring has had a significant impact on the environment such as pollution, global warming, and economic losses. It is responsible for wasting about 5% of the global gas supply where more than 350 million tons of CO2 gas are produced annually. There are many alternatives for gas faring. Flared gas can be converted into electricity via turbines, and gas-to-liquid (GTL) Technology. Also, Flue gas can be used for EOR. However, they are either under investigation or not economically viable. Therefore, a more efficient gas flaring system is crucial.
In this paper, a new gas flaring tip believed to alleviate the challenges of other flaring systems is presented. The tip itself is a unique design due to a bullet device seated on top of the flare. The bullet device has four holes with inside deflectors to push the gas to a single outlet at the top in a vortex. The bullet is attached to the flare tip with three springs that allow it to lift with 2 psig and to extend fully at 8 psig. This design will allow gas to travel around the bullet using the Coanda effect and ensures efficient oxygen.
The tip was evaluated over a wide range of gas capacities. Thermal radiation, isopleths, and noise levels were measured. In addition, flue gas composition and combustion efficiency were investigated. The results prove the new tip is superior to the existing gas flaring systems. As a cost-effective, smokeless tip with higher efficiency and cleaner flames, the authors recommend the new design to minimize flaring environmental impacts.
Exploration of Recovering Waste Heat in a Cascade Liquefied Natural Gas (LNG) Plant
Authors: Acharya Shisir , Wang Ting 
Published: February 2024

Abstract
Natural gas (NG) has lower and cleaner emissions compared to other fossil fuels such coal and petroleum, thus NG gas has been widely used in recent years to replace coal, diesel, or other petroleum derived fuels to generate power. However, many nations in the world have limited or minimal NG resources, importing liquefied Natural Gas (LNG) has become the only method for countries where transporting natural gas through land-based piping is not sufficient or not available, for example, like Japan, South Korea, Taiwan, Pakistan, to name a few.
LNG can be obtained when natural gas is refrigerated to the temperature around −260°F (−162°C). At this temperature, the original volume of the natural gas is reduced by 600 times. To reach this temperature, a multistage refrigeration system with intercooling and regeneration is required. The process of producing LNG is an energy intensive process, which demands a large amount of compression from multiple compressors. Each of these compressors is directly driven by a gas turbine. The gas turbine exhaust contains a large amount of useful energy, but often it is released into the atmosphere and ultimately wasted. The objective of this study is to identify methods to utilize this hot wasted exhaust and recover energy from it. This paper first provides a generic review of various existing commercial LNG production processes. Then a cascade LNG process is simulated to utilize up to four succeeding (cascading) vapor compression refrigeration loops to achieve the cryogenic temperature around −260°F (−162°C). This exhaust has been combined and the energy has been recovered through a Heat Recovery Steam Generator (HRSG). This recovered heat through HRSG has been utilized to run a Rankine cycle power plant to produce electricity. The results show that the wasted heat recovery system combined with a Ranking cycle can recuperate up to 47% of the wasted energy.
Photo-Switchable Optical Property of Two-Dimensional Transition Metal Dichalcogenides
Authors: Cunningham Connor , Pillai Srajan , You Jeong Ho , Ji Jaehoon , Choi Jong Hyun 
Published: February 2024

Abstract
Transition metal dichalcogenides (TMDCs) have received much attention for optoelectronic applications because of their band gap transition from indirect to direct as they decrease from multilayer to monolayer. Recent studies have experimented with the use of photochromic molecules to optically control the charge transport of two-dimensional (2D) TMDCs. In this work, a numerical study using density functional theory has been performed to test the possibility to control the optical property of 2D TMDC monolayers with various photochromic molecules. When the photochromic molecule’s highest occupied molecular orbital (HOMO) or lowest unoccupied molecular orbital (LUMO) energy levels are within the band gap of 2D TMDC monolayers, holes or electrons will transport to the photochromic molecules, resulting in the reduction of excitons in the 2D TMDC monolayers. The reduced optical response can be recovered by going through reverse isomerization of the photochromic molecules. Molybdenum disulfide (MoS2) and tungsten diselenide (WSe2) monolayers were tested with various photochromic molecules including azobenzene, spiropyran, and diarylethenes (DAE 2 ethyl, DAE 5 ethyl, DAE 5 methyl). The systematic study presented in this work displays that MoS2-Spiropyran and every diarylethene derivative used in this study except MoS2-DAE 5 methyl exhibited photo-switchable behavior.
Comparative Electrode Design for Piezoelectric MEMS Kinetic Energy Harvester
Authors: Janardhana Ranjith D. , Jackson Nathan 
Published: February 2024

Abstract
Microsystem based piezoelectric kinetic energy harvesters have been extensively investigated over the past decade. The most popular structure of these devices includes a cantilever consisting of a substrate, and a parallel capacitor (electrode/piezoelectric/electrode) layout. This type of structure has the ability to harvest energy by working in the d31 mode where the electrical potential is taken in the 3 (out of plane direction) while the strain/stress occurs in the 1 (in plane direction) direction. However, the d31 piezoelectric properties are approximately half the value compared to the d33 mode. Therefore, operating in the d33 mode should result in increased power output. A ferroelectric material that is able to alter its polarity is needed to investigate this potential design enhancement. This paper investigates the performance of both parallel plate capacitor and interdigitated electrode MEMS energy harvesters using lead zirconate titanate thin films using finite element modelling and experimental results to demonstrate the increase in power density, and the effects of varying the electrode configurations and dimensions.
Effect of EIS in a 3D Printed Non-Planer Array Patterned Microfluidic Devices
Authors: Kabir Shanzida , Zepeda Saenz Hector , Islam Nazmul 
Published: February 2024

Abstract
In recent years 3D printing is becoming popular among researchers for its reliability, cost-effective materials, and ease of use without having costly clean rooms. In this work we report the process of fabrication of an array patterned microfluidic device with its effect in Electrochemical impedance spectroscopy (EIS) and particle manipulator. With the optimized design of channel geometry and electrode pattern, this device can use in different lab-on-a-chip applications. A 3D printed microfluidic channel fabrication process is presented here along with a CAD drawing with microstructural dimension analysis. EIS is an expeditiously developing method used in characterizing materials and interfaces. By using equivalent circuits as models, it can determine the electrical properties of heterogeneous systems like membranes or electrolytes. For evaluating Impedance spectroscopy, a small amount of perturbing sinusoidal signal was applied to the electrochemical cell and measured the resulting current response. We take EIS measurements in three different electrolytes DI water (18.72μS/cm), tap water (666.12 μS/cm), and PBS 1 × (8235.24 μS/cm) with three different ranges of conductivity to observe their characteristics changes and to compare them. We analyze the electric double layer (EDL) effect for the electrode and electrolyte interface and how electron transfer kinetics and diffusional characteristics affect the spectra EIS is applicable to determine different electrochemical processes that can happen at the same time. Also, using AC electrokinetic (ACEK) flow the device can be used as a potential microfluid manipulator with its array electrode pattern. Both the micro-PIV and EIS experiments were done to verify the data validity of the microfluidics mixers.
Condition Monitoring of Cutting Tools by Feature Analysis of Vibro-Acoustic Sensing Signals
Authors: Lao Dongjing , Shen Yanfeng 
Published: February 2024

Abstract
This paper presents a vibro-acoustic sensing method for real-time Tool Condition Monitoring (TCM) for Computerized Numerical Control (CNC) machining. The method captures Contact Acoustic Nonlinearity (CAN) arising from periodic impacts between the cutting teeth and the workpiece to obtain the spectral domain characteristics of sensing signals captured by piezoelectric transducers. The tool wear evaluation metric is constructed, starting with analytical modeling of cutting signals using a nonlinear oscillator model. Numerical case studies are conducted where a periodic impact vibration signal is simulated and fed into the equivalent CAN reduced-order nonlinear oscillator model of a machine tool system to predict the dynamic response. Thus, the nonlinear response spectrum is obtained and the mechanism behind the spectral nonlinear characteristics is illustrated by simulating various wear severities and breakage situations of the cutting tool. Furthermore, nonlinear features are extracted from the vibration response acquired during CNC machine tool machining by low-cost piezoelectric sensors to diagnose the tool damage. Several damage indices are explored to quantify the severity of the damage, relating to spectral nonlinear features such as shifts in the position of the dominant frequency, increase in mixed-frequency response components, and generation of higher-order harmonic components. The analytical modeling results, the extracted non-linear features, and the damage index derived is validated against experiments and are able to effectively identify the severity of tool wears. The proposed method and findings provide a promising approach for the practical application in the field of smart manufacturing.
Identifying Sick Cells From High-Resolution Solid-State Micropore Data
Authors: Hafeez Abdul , Ilyas Azhar , Butt Ali R. , Iqbal Samir M. 
Published: February 2024

Abstract
Early detection of diseases such as cancer can drastically improve prognosis and treatment. To this end, solid-state micropores can measure distinct mechanical properties of diseased cells from their translocation behavior — detected as pulses in the temporal data stream of ionic current — and help diagnose diseases at early stages. However, the obstacle in such approaches is that the accuracy of the sensor is affected by noise, making the pulse detection task too subjective. This is inefficient especially when the disease-relevant data is only a fraction of the total acquired data. Thus, it is important to intelligently automate the detection process to eliminate the noise and to identify useful patterns towards error-free decision-making in real-time. This work describes a pattern detection approach based on moving-average filtering, which mitigates the impact of noise. Moreover, a detection threshold is computed from the mean and standard deviation of the data. The threshold is then used to detect different types of pulses stemming from the healthy and diseased human cells when these translocate through micropores. Extent of smoothing is an important factor for the data: greater smoothing suppresses the noise but deteriorates the pulse shape and vice versa. Additionally, the design approach computes useful features of the detected data and delivers the results for real-time analysis. This can help physicians and scientists to change their strategies of diagnosis by providing a validation of manual reviews.
Electronic Failure of Small Implantable Devices due to Moisture Ingress Through a Medical Grade Epoxy
Authors: Blue Simon , Munro Deborah 
Published: February 2024

Abstract
This article discusses the evaluation of hermeticity of epoxy-sealed enclosures for biomedical devices used inside the human body for long-term implantation. The aim was to prevent moisture ingress, which was evaluated under accelerated testing conditions with two medical grade epoxies, Loctite Hysol M-31CL and Master Bond EP40MED. A mathematical model was used to approximate the lifespan of a polymer-metal-epoxy encapsulation based on a desired maximum internal relative humidity of 55%. For small implantable devices, a humidity sensor often won’t fit in the available space, so a cobalt chloride paper was used inside the housing for this study, and a clear acrylic lid provided a viewport. The paper’s color changed from blue to pink at 55% relative humidity, and this was photographed and then evaluated with an algorithm to provide the daily average color value. The results showed that the type of adhesive was a critical factor in the expected lifespan for the device, and the EP40MED epoxy provided a superior lifespan against moisture ingress compared to the M-31CL epoxy. The study was limited by its interpretation of the color at which the internal relative humidity reached 55% as well as by slight variations in the lighting conditions for each day’s photograph of the paper. The results provide useful information for the design and development of biomedical devices at their final size under accelerated aging conditions and highlight the critical role that adhesives play in the expected lifespan of these devices inside the human body.
Sustainability and Recent Experimental Advances on the Production of Metallic Bipolar Plates of PEM Fuel Cell Using Electromagnetic Forming Technique
Authors: Karibeeran Shanmuga Sundaram , Rahiman Mohammed Abdul Kadar , Murugesan Pradeep Kumar , Justin Jebin Rex 
Published: February 2024

Abstract
The most troublesome challenge in overcoming the threats of energy crises, an eco-friendly energy source to replace fossil fuels greatly hinders the development of PEM fuel cells (PEMFC) with their ability to convert hydrogen gas and oxygen gas into electrical energy and water which offers clean, reliable, no pollutant and efficient power source in the automobile industries. The bipolar plates (BPPs) are one of the influential components of PEMFC, where the BPPs account for 60–80% of total weight and 45–60% of total manufacturing cost of PEMFC. The potential surplus of metallic bipolar plates is optimistic for replacing conventional carbon-based (graphite) BPPs while its cost is still relatively high. Manufacturing these plates through Electromagnetic forming (EMF) is highly suitable for mass production at Uniform pressure actuators. EMF is a technology of forming a conductive sheet metal workpiece at high speed without physical contact by applying a high-impulse electromagnetic field to the workpiece and no working medium is required. The EMF technique forming of metallic bipolar plates micro-channel was investigated in the Copper sheet metal of 200 μm. A large variant of serpentine-like flow field structures was constructed and evaluated by running 3D simulations of Ansys LS-DYNA.