bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combustion of Hydrogen and Natural Gas at Elevated Air Temperature Using 3D Printed Burner
Authors: Murugan Raju , M. V. R. Suresh , Chauhan Rahul Singh , Alemela Reddy 
Published: February 2024

Abstract
Hydrogen is a clean-burning fuel that produces only water vapor when combusted, making it a highly attractive option for reducing greenhouse gas emissions and combating climate change. Hydrogen can be produced from a variety of domestic sources with potentially near-zero greenhouse gas emissions. However, combustion associated with hydrogen for industrial heating applications poses some serious challenges in terms of flame stability and high flashback propensity due to its highly reactive nature. At the same time the burner hardware is also expected to be fuel flexible (with varying LHV), i.e., to be able to operate with different blends of LPG/NG and H2. This demands a bit complex geometry to mix the fuel and air in an efficient way (fuel nozzle sizing) and at the same time to mitigate the flash back risk and introduce complex cooling schemes. Towards this, advanced additive manufacturing techniques (3D printing) open the doors to manufacture highly complex systems and facilitate the scaling of complex systems. 3D printing is an additive process, where material is only used where it is needed. Thus, it leads to reduced material wastage and more sustainable manufacturing practices.
This experimental study aims to determine the operating margins of a fuel flexible 3D printed burner, that is designed to burn different fuel blends up to 100% hydrogen. Following thorough Computational Fluid Dynamics (CFD) analyses, the burner was designed for and produced through additive manufacturing technology (3D printing). As a first validation and demonstration, tests were carried at atmospheric pressure test conditions, using natural gas (NG) and hydrogen (H2) up to 250 (kW) of thermal power and air preheating up to 500°C.
The results demonstrated the burner capabilities in terms of low emissions (below 3 ppm) low pressure drop (below 2.5%) in a broad operating window (flame temperatures up to 1850K), relevant for gas turbine and other industrial heating system applications. The first tests with the 3D printed burner, with integrated fuel injection and cooling concept system showed encouraging results in terms of flash back resistance and at the same time meeting low pressure drop system compared to the conventional swirl stabilized flames.
Data Synthesis Through Deep Generative Models and its Effectiveness in Improving Defect Inspection Models
Authors: Kulkarni Ninad , Gupta Rahul , Kalyan Vijayasri , Bhate Ujwal 
Published: February 2024

Abstract
Recent advances in Deep Generative Models (DGM) have demonstrated their remarkable ability to synthesize highly realistic images. This work examines the effectiveness of DGM produced synthetic images in the context of training AI models for visual asset inspection, which is plagued by a host of challenges including limited data volumes, extremely imbalanced datasets owing to rarely occurring defects, poor quality and consistency of images, spiraling costs and time for data labeling, to name a few. This paper presents an approach to using DGMs, specifically Generative Adversarial Network (GAN) models, to create synthetic images containing defects and damage. The objective of the approach goes beyond generating good quality images and extends to synthesizing a distribution of images with a variety of defect features without significantly altering the object structure.
The paper concludes by discussing multiple metrics to assess the effectiveness of such synthetic data in training downstream asset inspection models and presents the results of multiple experiments on real-world data.
Testing and Modeling of Generalized K-Omega Turbulence Model and Validation on Highly Efficient Centrifugal Compressor (HECC)
Authors: Ranjan Shivani , Kumar Shailesh , Qizar Mohammed , Mansour Mahmoud 
Published: February 2024

Abstract
The paper outlines the CFD study carried out on the Highly Efficient Centrifugal Compressor (HECC) consisting of three blade rows which are an Impeller (main blade/splitter blade), a Diffuser (main/splitter vane) and a Deswirl. The commercial Ansys CFX 2021R2 CFD package has been used for its numerical simulation with a major focus on turbulence modeling to predict the highly complex flow field dominated by three-dimensional, viscous, and unsteady mechanisms in centrifugal compressors. The steady-state CFD calculations were performed to assess the generalized k-omega turbulence model and capture the lessons learned along with the limitations and inconsistencies of the turbulence model. The quantitative and qualitative aero performance results are discussed and validated against the available experimental data. It has been observed that the obtained results are in good agreement with the experimental data over the characteristic curve from the choke to the stall side.
Performance Enhancement Kit for Frame 51 Machine With DLN Combustor
Authors: Soman Abhimanyu , Cocchi Lorenzo , Peddi Mallikarjuna , Avaiya Nikunj , Devi Ravindra , Santhana Gopalakrishnan Babu 
Published: February 2024

Abstract
A Performance Enhancement Kit (PEK) is introduced to infuse the latest technology to MS5001PA fleet there-by existing customers benefit from increased output, extended inspection intervals, improved reliability, and operability. The kit includes advanced-technology combustion system with improved design of hot gas path (HGP) components. The components in the KIT are designed for either enhanced output of 6% or for an increased interval between repairs or increased ‘Mean Time Between Maintenance’ (MTBM) from 24khrs to 35khrs. Initially PEK was introduced as part of MS5001PA in 2016 for standard combustor. Present study shows its application to Dry Low NOx (DLN) combustion system without affecting Maintenance Interval (MI). PEK DLN configuration alters the combustion and in-turn the Stage 1 Nozzle inlet profile. High fidelity CFD computations were performed to evaluate impact of these altered profile on HGP components, especially the thermal distribution and its impact on durability. Adiabatic wall temperatures obtained from CFD were used in developing heat transfer and flow temperature in the flow path locations. These were used to perform thermo-structural assessment for HGP components using ‘Finite Element Analysis’ (FEA) tools. With this evaluation, durability of HGP components in terms of LCF, creep was thoroughly assessed to ensure part life is meeting MI. Detailed high-fidelity FEA shows that, creep, oxidation, and ‘Low Cycle Fatigue’ (LCF) meet the design requirements for both life extension as well as the power increase conditions with DLN combustor profile. To gain confidence, MS5001PA durability results were benchmarked with field experience of ‘Standard’ (STD) and DLN configuration which shows coherent results with Creep and LCF. This gives confidence in thermal profile which was developed for PEK STD and DLN configurations. Based on detailed thermo-structural assessment, the maintenance factor was set to 1. This paper presents the latest methodology used in CFD for aero flow prediction and high-fidelity Finite Element (FE) assessment used for durability prediction of HGP components.
Development of Machine Learning Model to Predict Mechanical Failure of Gas Turbine Disc
Authors: Seth Alok Kumar , Shrivastava Rishabh , Rai Amit Kumar 
Published: February 2024

Abstract
Gas Turbine is a mechanical system which is used for power generation since decades. Its components are highly stressed and exposed to very high temperature. It operates on various environmental condition which experience numerous loading patterns. In all these operating conditions, Gas turbines must operate with higher efficiency to meet changing power requirements. Each component must be assessed for different mechanical failures and predict life during design and development.
Gas Turbine Rotors which comprise of several discs are one of the most critical components in gas turbine. GT rotor is subjected to high temperature and centrifugal load during their operations. In such conditions, predicting the failures becomes utmost priority.
This study aimed to evaluate the effectiveness of Machine Learning (ML) techniques to predict the failure in a gas turbine Rotor Disc. For this study, a simplified geometrical 3D model of Turbine Disc was used along with Cooling holes, Hub geometry with Sealing arm and lifting features. Four input variables i.e., cooling hole mass flow, temperature of cooling air, purge hole mass flow and temperatures of purge air were used as input feature to the machine learning model. Steady-state thermo-mechanical analysis were performed to evaluate the metal temperature and subsequently the stress and life of the component under various load cases.
A machine learning based surrogate model was developed based on the data extracted from 3D thermo-mechanical FEA assessment. The generated dataset was randomly divided into 75:25 ratio for training and testing of ML models respectively. Multiple models based on different algorithms were created for predicting disc LCF life. Then, these were evaluated with test set to select the model using various Evaluation Metric.
Machine Learning techniques such as Logistic Regression, Random Forest and Support Vector Machine algorithms were compared using Precision, Recall and F1 Score. The results were validated through Confusion Matrix and ROC (Receiver Operating Characteristics) curves. This study demonstrates that ML techniques has potential in predicting failures/life of a component.
This study will be helpful for the assessments performed during later stage of product life cycle for example overhaul, lifetime extension or if any manufacturing deviations happen. Mostly these assessments are very critical and time dependent. As we use conventional methods for component assessments, it takes significant time and cost. Therefore, this study and its implementation would make current industrial practices efficient and cost effective.
Spray Interaction in Flat-Fan Injectors and its Effect on Cleaning Effectiveness of Gas Turbine Online Water Washing System
Authors: Kumar Kiran , Sahu Srikrishna , Devi Ravindra G. 
Published: February 2024

Abstract
Compressor fouling due to the deposition of airborne particulates on the compressor blades is a major cause of the degradation of compressor performance and the decline of overall gas turbine efficiency. The online water washing technology refers to an effective method to clean the compressor blades during engine operation. In such systems, typically a series of flat-fan injectors are peripherally located at the entry section of the gas turbine which injects water sprays into the intake air flow. The injected water spray droplets are transported towards the compressor and impinge on the compressor blades, thus removing the foulant. However, such injector arrangement usually leads to the interaction of adjacent sprays which may modify the resulting spray characteristics such as droplet size, velocity, and momentum. Hence, the study of spray interaction in the flat-fan injectors and its effect on the blade cleaning effectiveness is important for the design and development of water washing units. The objective of the present work is to study the spray interaction in two adjacent flat-fan injectors under open atmospheric condition as well as in an experimental test facility that essentially consists of a suction type wind-tunnel that mimics the gas turbine compressor inlet conditions in an optically transparent test section. Different optical diagnostic tools are used to visualize the spray interaction process as well as measure droplet size and velocity. To study the effect of spray interaction on blade cleaning, foulant-coated coupons (SS flat plates) are placed inside the test section of the wind tunnel and are exposed to the sprays for a fixed interval of time. The foulant cleaning efficiency is measured by weighing the coupon before and after the cleaning tests. A parametric investigation is carried out to investigate the cleaning efficiency for different air flow velocities, angle of attack, and injector separation distance. The current experimental results not only further elucidate the understanding of the blade cleaning process in online water wash systems but also provide valuable data for the validation of numerical spray simulations.
Experimental and Numerical Investigation of Velocity Flow Field in a Novel 3D Printed Triple Swirler Burner
Authors: Thombare Mahesh R. , Pillai Sidharth K. , Murugan Raju , Pillai Madhushankar , Balusamy Saravanan 
Published: February 2024

Abstract
Efficient and clean combustion is vital in combustion systems, but achieving perfect fuel-air mixing is challenging. Gas turbine combustors use multiple swirlers to improve mixing and stabilize flames. This study investigates a 3D-printed triple-swirler burner (TSB) to enhance gas turbine combustion systems. The TSB was tested in a vertically configured apparatus, with air passing through before exiting. Experimental and numerical methods were used to study the flow field downstream of the TSB. Different TSB designs with varying swirl numbers and rotational directions were tested at different airflow rates. The experimental data obtained using Stereo Particle Image Velocimetry (SPIV) and the CFD results using Large Eddy Simulation (LES) provided insight into flow physics and helped optimize the design of the TSB. Simulation outcomes are presented and compared with experimental data at the exact locations in the flow field. Results showed that TSB2 had a longer residence time than TSB1. Strong bubble vortex breakdown (BVB) was observed in the upstream region, caused by the counter-rotating tertiary swirler. Downstream, weak conical vortex breakdown (CVB) was observed as the tertiary swirler’s influence diminished.
Conceptualization of a Portable Vacuum Pumping System for Dead Volume Dispensing of Crude Oil From Crude Oil Storage Tanks
Authors: Das Manosh Jyoti , Sahoo Niranjan 
Published: February 2024

Abstract
In crude oil storage-dispensing terminals often problems are encountered regarding dispensing and processing of crude oil at near dead volume capacity of the tanks. Similar problems are encountered while cleanout procedure of tanks for maintenance and repair. In our first consideration processing of crude for treating or dehydration is brought to picture. For crude processing or tank to tank transfer problem arises below dead volume with high flow high pressure circulation pumps. The problems observed are low suction pressure, reduced flow and pressure at discharge end, frequent gas formation at suction, high flow induced vibration at pump suction and frequent failure of dynamic seals. Most pumps used in this scenario are centrifugal pumps (following API 610 codes and API 682 for mechanical seals). For our purpose single stage centrifugal pump is considered. The pump deigns and dead volume level calculation attributes to the problems encountered. Moreover, during the clean-out procedure it becomes difficult for most pumps even with low NPSHR to efficiently pump out the liquid below dead volume level. This creates severe volume build-up and even causes damage to pumps at very low level partial dry run condition. Our aim is to conceptualize and furthermore develop a compact vacuum-pump system which can be used for continuous delivery of fluid even beyond specified dead-volume level. The equipment would have the capability to work on very low-level fluid storage. Again, in traditional vacuum and pump system there is a drawback of swing operation of vacuum and pump system which greatly affects the operation time of any process. This literature will help in identifying the core problem of swing operation and inline draw a concept of the new pump-vacuum system which eliminates need for a swing operation i.e., simultaneous operation of evacuation and pumping can be carried-out. Also, it is aimed to explore further applications of the system for booster application. Vacuum systems consist of vacuum pumps and tanks mounted on a skid or truck. The vacuum pump creates a vacuum in the tank and the oil moves directly through a hose or pipe to the tank from the skimmer or the source of the oil. The oil does not go through the pump, but moves directly from its source into the tank. Vacuum systems can handle debris, viscous oils, and the intake of air or water. The vacuum tank requires emptying, however, which is usually done by opening the entire end of the tank and letting the material move out by gravity [1].
Diameter-to-Chord Ratio Effect on the Aerodynamic Performance of Small-Scale Darrieus-Type Straight-Bladed Vertical Axis Wind Turbine
Authors: Naik Kabita , Sahoo Niranjan 
Published: February 2024

Abstract
The growing interest in small-scale Darrieus-type straight-bladed vertical axis wind turbines (SB-VAWTs) presents a novel outlook for the conversion of wind energy, departing from horizontal axis wind turbines. The SB-VAWTs are favourable alternative energy sources to generate independent off-grid electrical power in complex wind environments. The current study aims to explore and understand the effect of blade geometry on the efficiency and self-starting ability of the SB-VAWTs. Therefore, three different diameter-to-chord (D/c) ratios have been investigated at various tip speed ratios (λ). Accordingly, numerical simulation on Darrieus-type SB-VAWTs has been carried out with D/c ratios of 2.5, 3.5 and 4.5 and presented a comparative analysis between their power and torque coefficient. The VAWT with a D/c ratio of 2.5 is conducted in a subsonic wind tunnel of an open circuit type with test section dimensions of 600 mm × 600 mm × 2000 mm to validate and support the numerical findings. The flow physics analysis for all three D/c ratios is also studied by simulations to understand the stability and reliability of SB-VAWTs. An improvement of 13% and 54% is found in the maximum power coefficient by the Darrieus-type SB-VAWT with a D/c ratio of 4.5 as compared to the d/c ratio of 3.5 and 2.5 at λ = 1.8. Smaller D/c ratios exhibit superior self-starting capability in Darrieus-type SB-VAWTs compared to larger D/c ratios at lower λ values. The outcomes revealed that the proper selection of D/c ratios can enhance the aerodynamic performance and starting torque of Darrieus-type SB-VAWT.
Efficiency Assessment of Compressed Air Energy Storage System Coupled With Thermal Energy Storage Unit: Review
Authors: Adamu Assegie Mebratu , Siram Ojing , Kalita Pankaj , Sahoo Niranjan 
Published: February 2024

Abstract
The compressed air energy storage system is one of the emerging storage systems that has recently gained significant attention due to its large storage capacity, eco-friendly, clean technology, and extended life cycle. The present study makes a comprehensive review on the implication of CAES system coupled with TES system. It is noted that when the CAES system is in operation, the cooling system dissipates the majority of the heat produced during compression into the environment, thus reducing its efficiency to 54% or less. Therefore, the post-compression thermal energy can be coupled with an adiabatic thermal energy storage system, which later on can be used to enhance the efficiency of the CAES system. According to its energy and exergy analysis, the adiabatic CAES system can achieve an efficiency of 70% when used in conjunction with a direct-contact type of packed bed (TES) energy system. Past studies demonstrate that the efficiency of A-CAES combined with a heat recuperator increases with more continuous operational cycles and reaches 57% efficiency. In general, it is due to the materials type, geometry, and thermo-physical property, the variation in the thermal efficiency of the TES system is observed that leads to variation in CAES efficiency.
Design and Numerical Analysis of a Lean Burn Combustor Liner Inlet for Micro-Gas Turbine Engine Applications
Authors: Tyagi Vatsal , Divyansh Ayush , Jamod Preetam , K. P. Shanmugadas 
Published: February 2024

Abstract
Lean burn combustion systems of low-emission modern gas turbine engines admit ∼70–80% of the compressed air through the fuel injector and the remaining air is passed through the liner assembly. The paper focuses on developing an intake geometry to accomplish a 70:30 mass flow split between the injector and liner. A lean burn injector and a liner assembly are developed following the existing design rules and extensive numerical simulations are performed to optimize the combustor assembly. The intake geometry is designed considering different operating parameters such as mass flow split ratio, compressor pressure ratio, liner and injector pressure drop. The pressure drop across the injector is limited as 4% and the liner is optimized for a pressure drop of less than 2% across the annulus of the liner. The diffuser section and intake cowl of the combustor are modified to achieve the required flow velocities through the liner and injector. The topology of the central toroidal recirculation zone and effusion flow velocity field are obtained as per the design requirements. The annular liner passage is modified by providing baffle plates to regulate the mass flow and thereby controlling the mass flow split into the intake section. The intake section is designed such that the required flow split is achieved while keeping the pressure drop and other losses to the minimum. Several geometrical iterations are done until the above goal is achieved. Efforts are currently underway for the experimental validation of the test results.
Wind Tunnel Assisted Analysis on the Effect of Span-Wise Separation of Small Wind Turbines: A Near Wake Region Study
Authors: Kumar Ravi , Siram Ojing , Saha Ujjwal K. , Sahoo Niranjan 
Published: February 2024

Abstract
In this work, an in-depth study has been made to examine the benefits of span-wise placed horizontal axis wind turbine configurations. The model turbine rotors have similar configurations with a sectional profile of SG6043, and are tested at low tip speed ratio conditions. The study has been performed for the two span-wise placed rotors having tip-to-tip separation distances of 1R (R being the rotor radius) and 0.5R, and are analyzed within the near-wake regime. The wind turbine wake assessment has been carried out in an open circuit wind tunnel with the help of a constant temperature hotwire anemometry. The downstream velocity deficit assessment shows that the wake of closely placed turbines undergoes faster interaction at short downstream distances, where the whole wake is characterized as an array of localized high velocity-deficit regions associated with each rotor. However, as the wake moves downstream, the rotor wakes start interacting with each other until they eventually form a single wake. The wake recovery rate of the span-wise placed rotors is enhanced by the increase of rotor spacing and wind speed. Furthermore, the tip of the blade generates helical vortices due to which a tangential component of velocity is added in the stream velocity vector. This gives velocity greater than stream velocity in ± 0.75R to ± 1.25R along a lateral direction with respect to wake centre.