bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational fluid dynamics based transient investigation of the penstock in a hydropower plant
Authors: Khan F , Kumar A , Abbas A , Gupta D P , Binjolkar P 
Published: December 2024

Abstract
Water hammer is a hydraulic transient phenomenon that occurs at hydropower plants (HPP) when the discharge is rapidly decreased or closed, which can damage the HPP components, mainly penstock. Sudden Pressure rise and collapse of water columns or cavity forms due to the low pressure may cause severe damage. Understanding transient flow behavior is necessary to prevent harmful pressure fluctuations and ensure power plant safety. The present 3D computational fluid dynamics (CFD) study is carried out to predict pressure fluctuations, the occurrence of any cavitation, and water column separation at critical locations in the water conductor system from the surge tank to the turbine inlet due to low pressure caused by the closing of the hydraulic turbine guide vane valve at downstream of the penstock. The hydraulic domain of the penstock, connecting the head race tunnel to the turbine inlet, is created as per the HPP UHL-III actual water conductor system elevations, bent bifurcations, and geometric sizes. Transient CFD simulations for different load rejection conditions were performed in the Ansys CFX by modifying the Unsteady Reynolds Average Navier’s Stoke equation (URANS), incorporating the elastic effect of penstock material, and considering the variable density of the water, taking the compressibility. Transient pressure in the penstock was recorded at various locations. Further, minimum pressure inside the flow domain that falls in the no-column separation zone was also obtained.
Numerical Study of Sediment Erosion of a Francis Turbine with change in guide vane design
Authors: Kumar Sahu Rohit , Kumar Gandhi Bhupendra 
Published: December 2024

Abstract
The guide vane is a primary component influencing the sediment erosion of the turbines. For the current work, Francis turbine installed in the Bhilangana-III hydroelectric plant is numerically modelled to investigate the effect of guide vane design on turbine erosion. The existing guide vane profile has been modified to adopt an unsymmetrical hydrofoil shape. Two numerical models of the scaled turbine are developed using the commercial code ANSYS CFX. The first model is prepared with the existing guide vane, whereas the second model incorporates the modified guide vane. The erosion rate density is determined using a modified Grant and Tabakoff erosion model for different operating conditions and a sediment concentration range of 500 – 2500 PPM. The turbine with modified guide vanes showed a reduction in wear of guide vanes and runner by 12-23 % in comparison to that of the existing guide vanes. Further, the erosion is higher for both the part and high load conditions as compared to the best efficiency point operation.
Streamline rotodynamic pump model for two-phase flow simulation
Authors: Martel Simon , Matteo Laura , Mauger Gédéon , Bouvard Timo , Fortes-Patella Regiane 
Published: December 2024

Abstract
This study is concerned with the simulation of water-vapor two-phase flows in pressurized water reactors (PWR) primary pumps. The correct modeling of such flows is essential to predict the consequences of a Loss Of Coolant Accident (LOCA), an accident scenario involving a rupture in the reactor primary circuit. During such accidents, pressure loss leads to important coolant vaporization in the circuits, pumps and other system components.
A review of turbomachinery streamline models, used to represent pumps in system codes, is presented. Particular attention is paid to the model used in the CATHARE-3 system code, as its development is the motivation for the present work.
Numerical simulations were then performed using CATHARE-3 streamline pump model, currently validated for single-phase liquid flows. These simulations included test cases for pure liquid and vapor conditions, as well as one two-phase flow case, with inlet void fraction of approximately 10 %.
For pure liquid water, the agreement is good for discharge between 75% and 150% of nominal discharge. Results are satisfying up to 300% of nominal discharge for the single-phase vapor case. The two-phase results are close to experimental values around 75 and 130 % of nominal discharge.
Further work is required in order to consolidate the physical analysis and to improve and validate CATHARE-3 streamline pump model for two-phase flow conditions.
Simulation and validation of a Francis turbine load rejection procedure using OpenFOAM CFD code
Authors: Masoodi F , Goyal R 
Published: December 2024

Abstract
The effect of off-design operation on the health of hydraulic turbines is known to be adverse, with substantial compromise in efficiency, due to evolvement of flow instability in the draft tube and consequent pressure fluctuation. The worst-case scenario may entail resonance between developed pressure fluctuation and system natural frequencies and therefore lead to power swings, possible mechanical vibrations and machine wear and tear. Present global energy ambition, however, necessitates frequent off-design operation and as such development of accurate numerical methods to determine the anomalous flow field in the turbomachine is mandated. To this end, a load rejecting transient operation of a model high head Francis turbine from design operating point to part load condition is simulated using a hybrid turbulence modelling approach. A detailed analysis of the draft tube velocity field is carried out after validation of the test case with experimental investigations that have discerned similar results. Spatio-temporal features, such as central flow stagnation, flow separation, central flow recirculation and development of a precessing vortex core, which are embodiments of the vortex breakdown phenomenon are thoroughly analysed and discussed. Finally, the draft tube flow is visualized using streamlines on the meridional plane and tracked as the turbine transitions from design to part load operating conditions.
The influence of the free runners on the decelerated swirling flow from the draft tube cone of hydraulic turbines.
Authors: Bosioc A I , Szakal R , Tanasa C , Gherghe G , Susan-Resiga R.F. 
Published: December 2024

Abstract
Nowadays the renewable energy plays an key role in the development of safe and clean energy. Worldwide and especially in Europe the development of renewable energy is focused on development of new wind and solar power plants. Accordingly, these energy technologies introduce high power fluctuations in the electrical system, which are necessary to compensate by other energy sources. To compensate these power fluctuations, the electrical systems use new technologies as high-capacity electric batteries or classical technologies as hydropower. The new technologies as the batteries are used rarely, while the hydropower remain the only technology to response quickly at the electrical systems requirements. The hydropower with the hydraulic turbines has the capability to adapt faster at the electrical system requirements, but for hydraulic turbines this requirement comes with hydrodynamic consequences. Accordingly, at the outlet of the hydraulic turbines (in the conical diffuser), the hydraulic instabilities are developed (vortex rope occurs) accompanied by high pressure fluctuations. The present paper proposes adding free runner at the inlet of the conical diffuser, which rotates on an axle, with null momentum. For this purpose, have been designed and manufactured a series of four free (additional) runners (with different numbers of blades) to assess the performances of this method. Experimental investigations of unsteady pressure and velocity profiles using LDV system were performed downstream of the free runner. The velocity measurements have been performed on three survey axes, by measuring the meridian and circumferential velocity profiles. The unsteady pressure measurements were achieved at the conical diffuser wall on two levels. To better analyse the relevance of the free runners, the Fourier transform is applied on pressure signals. The results will clarify the functionality and limitations of this method for swirling flow control.
Assessment of the distributor layout influence on the vortical flow within the hydraulic turbine
Authors: Štefan David , Klement Jan , Urban Ondřej , Rudolf Pavel 
Published: December 2024

Abstract
The study presents analysis of conditions for the onset of vortices in the simplified geometry of the turbine domain. The simplified geometry, used for this analysis, is based on the physical model of the bladeless swirl generator developed by the research group from Brno University of Technology. This swirl generator was previously used for several studies of the spiral vortex structures generated in the diffuser part. In original geometry there are no guide vanes or other driving geometry features, thus the mixing mechanism is realized randomly, is strongly time-dependent and its behavior is linked to the swirl ratio between the axial and tangential inflows. From previous studies, the appearance of vortical structures with columnar-like shape was identified. Thus, the main aim for the current study is to assess the influence of distributor blade cascade on the onset and behavior of such vortical structures which resembles the ones observed in hydraulic turbines at low load conditions. For selected swirl ratio the distributor blades are designed specifically to influence flow with minimal effect. The distributor layouts with different number of blades are tested. The dynamics of vortices, their spatial shape and extend are examined through several post-processing tools. The results are mainly based on the CFD simulation employing a hybrid RANS+LES turbulence model.
Impact of Aerofoil Shapes on the Performance of Darrieus Vertical Axis Turbines: A Computational Study for Offshore Wind and Hydro Applications
Authors: Sharma Shubham , Singh Tomar Shivam , Dewan Anupam 
Published: December 2024

Abstract
An increasing energy demand, coupled with the depletion of fossil fuels and rising pollution levels, necessitates a shift towards renewable energy sources. Wind and hydro energy are a prominent renewable energy source, constituting more than 20% of the global electricity production. The objective of this study is to investigate the influence of different aerofoil shapes on the performance of Darrieus vertical axis turbine for the optimum tip speed ratio of 3.0 using Computational Fluid Dynamics (CFD) simulations. The focus is on six aerofoil profiles, namely, NACA 0012, NACA 0021, NACA 0030, S-1046, NACA 4421 and NACA 2412. Open-source CFD software OpenFOAM 9.0 is employed to perform two-dimensional unsteady Reynolds-Averaged Navier-Stokes (U-RANS) simulations using the SST k-ω turbulence model. This approach allows for the analysis of fluid characteristics around the turbine blades and an assessment of the aerodynamic performance of Darrieus turbine. The observed results provide an insight into the performance of various aerofoil profiles and help understand their strengths and shortcomings. By comparing the results, the aerofoil shape that yields the highest performance under the given conditions is identified. Additionally, the study investigates the effect of using asymmetric aerofoils on Darrieus turbine performance. This study is relevant to the optimization of the aerofoil shapes which can further enhance the efficiency and effectiveness of Darrieus turbines.
Assessment of synergistic cavitation and silt erosion performance of hydraulic turbine steel
Authors: Pechetti Durga , Chatterjee Dhiman , Kamaraj M 
Published: December 2024

Abstract
Hydraulic turbines endure degradation from cavitation erosion, silt erosion, corrosion, and fatigue, with combined silt and cavitation erosion exacerbating machinery deterioration, increasing repair costs, and reducing lifespan. While standardised tests for silt and cavitation erosion exist, they do not fully assess material suitability for such conditions. This study presents an accelerated testing methodology for 13Cr-4Ni Martensitic Stainless Steel, commonly used in hydraulic turbines, by comparing the effects of cavitation erosion, silt erosion, and combined cavitation and silt erosion. Experimental conditions include a submerged cavitating jet and two symmetrically placed submerged silt jets at a 30° impingement angle. Mass loss measurements are recorded to quantify performance under cavitation erosion, silt erosion, and combined cavitation and silt erosion. SEM imaging reveals distinct failure modes induced by these erosive modes. Results indicate that combined cavitation and silt erosion accelerate material degradation significantly, causing approximately 37 times more mass loss than the sum of their individual effects.
Retrofit and assessment strategies on heritage buildings: a case study of bank archive building in semarang old town area
Authors: Hermawan F , Raharjo P , Suwignyo R H D , Indarto H , Pamungkas G 
Published: December 2024

Abstract
Retrofitting in cultural heritage buildings to be revitalised has quite complex challenges, in addition to problems Efforts to maintain the performance of technical strength and repair limits on building elements are not flexible such as new buildings. This research aims to evaluate the method of implementing the revitalization of cultural heritage buildings through structural assessment. The case study method used on the Bank Archives Building object elaborated analysis to determine the safest Retrofit strategy. The analytical method used in this study is quantitative method using primary data obtained from direct observation and secondary data obtained from previous research case studies. The results showed that in planning a retrofit at the Bank Archives Building there were several technical and non-technical obstacles. Thus, the assessment method chosen includes several methods, including visual detail inspection, four non-destructive tests, one destructive test, and one soil test. These data are used to perform structural and geotechnical analysis. The results of structural analysis show that the quality of concrete in the structure of the Bank Archive Building does not meet the technical requirements of the building while the results of geotechnical analysis show that the decline in the structure of the Bank Archive Building has relatively little potential. The retrofit strategy that can be applied is a bending moment frame from a steel profile. This aims to increase the load capacity evenly distributed on the structure of the Bank Archives Building.
Diatoms as a bio-indicator for the coastal environment changes in Pasarbanggi mangrove conservation area, Rembang, Central Java
Authors: Kurniasih A , Soeprobowati T R , Dianti  , Putri E H , Jayanti A G R , Wanadri S B , Sujarwo P A 
Published: December 2024

Abstract
The coastal area of Pasarbanggi, Rembang has experienced significant coastline changes in the last 30 years. Changes in the stability of coastal ecosystems can be tracked by using bio-indicators whose traces are recorded in sediment. This research was conducted to determine changes in the ecosystem in the Pasarbanggi coastal area and its relationship to mangrove development using diatoms as the bio-indicator. Diatoms data is calculated to determine the abundance and diversity of its individuals. Based on the diatoms analysis, it is known that in the interval 26–50 cm, the abundance of diatoms is dominated by freshwater species, including Cyclotella meneghiniana and Cyclotella ocellata. From the satellite image, in 2002, the mangrove area has not developed yet and the sedimentation process is dominant. In the layer above it, at intervals of 1-25 cm, the sediment deposited in marsh environment. The diatoms diversity increased with the emergence of brackish and marine diatoms such as Tribionella granulata and Amphora coffeaeformis. In satellite imagery from 2018 to 2022, it appears that the development of mangrove area is significant. This shows that along with the mangrove development, there is an increase in ecosystem stability characterized by an increase in the diversity of diatoms species.
Recovery of solid waste as refuse derived fuel (RDF) to develop urban waste management through community empowerment
Authors: Zaman B , Sumiyati S , Wati H R , Aisy A R 
Published: December 2024

Abstract
Refuse Derived Fuel (RDF) is a solid waste processing technology that converts waste into fuel using its calorific value. Solid waste can be processed into RDF as briquettes in a smaller-scale society. Kalisalak Village, located in Batang District, Batang Regency, has the potential to utilize dry leaf waste into bio briquettes as a substitute for LPG gas for cooking. More than 80% of the Batang Regency area is agricultural land, so there is a lot of organic solid waste, especially dry leaves. This study aims to develop the potential of RDF as an alternative waste processing method to produce high-value products through community empowerment. The activity stages consist of field surveys, product prototype making, outreach and training for the community, and monitoring. The RDF process adopts a thermal method in processing waste due to its efficiency in recovering waste into renewable energy in a relatively short time. Dried leaf waste will go through a bio-drying process to reduce the water content by increasing its calorific value, thus producing waste with a lower water content. The bio-drying process is carried out using simple tools easily obtained by the local community. The resulting RDF bio briquette product can be sold and used as charcoal fuel.
Deployment of a Modern Sustainable Agricultural System Based on Drip Irrigation and Organic Liquid Fertilization in Patemon Village
Authors: Samadikun B P , Syafrudin  , Sumiyati S , Octaviani Y N , Andarista A F 
Published: December 2024

Abstract
In this era, technological advancements in agriculture are burgeoning rapidly. Despite widespread adoption, traditional practices persist in many regions, as exemplified by Patemon Village, where farmers rely on manual irrigation and fertilization. Additionally, synthetic pesticides continue to be widely used due to their perceived speed and efficacy in addressing pest issues. However, synthetic pesticides have drawbacks such as pest resistance, the killing of natural predators, environmental pollution issues, and are extremely hazardous to human health. This research aims to develop a systematic irrigation and fertilization system that assists farmers in optimizing their time and energy while minimizing wastewater usage and promoting the adoption of liquid organic fertilizers that support higher-quality and environmentally friendly agriculture. The design of the automated irrigation and fertilization system utilizes a drip irrigation system. The liquid organic fertilizer produced utilizes natural resources from plants and animal waste. The outcome of this program is the implementation of modern farming practices with automated irrigation and fertilization, as well as the use of environmentally friendly liquid organic fertilizers.
Impact of a municipal solid waste processing facility on microplastic pollution in Indonesia’s waterways
Authors: Andarani P , Rahma H H , Ningrum A W P , Istirokhatun T 
Published: December 2024

Abstract
Major cities are particularly affected by the escalating issue of municipal solid waste (MSW) pollution. Among the various forms of waste, plastic is especially concerning due to its persistence and tendency to fragment into microplastics. This study focuses on the Jangli River located in Semarang City, Indonesia, to quantify and characterize riverine microplastic pollution and assess the impact of the nearby a MSW Temporary Processing Site (TPS). Through water sampling, field observations, and laboratory analysis, we identified and classified microplastics by color and type, determining their abundance across different river points. Our findings reveal a correlation between the proximity to the processing site and increased microplastic levels. Specific hotspots along Jangli River were identified after the location of TPS, highlighting areas with the highest microplastic contamination. This research underscores the urgent need for targeted interventions to manage and mitigate secondary microplastic pollution, specifically solid waste, in Indonesia’s waterways, advocating for effective environmental control measures to protect aquatic ecosystems.
Assessing the transition from environmental education to education for sustainable development: a global perspective in higher education
Authors: Farliana N , Hardianto H 
Published: December 2024

Abstract
Education for sustainable development (ESD) is an official commitment driven by the United Nations (UN). In contrast, environmental education (EE) emphasizes environmental protection more. This analysis aims to assess the effectiveness and acceptance of the transition from EE to ESD, particularly among researchers in higher education institutions. This way, A global overview can be provided, highlighting the regions that adopt each educational model. The methods used include a systematic review for literature selection and meta-analysis parameters for data analysis. From the 7.439 papers analyzed, ESD’s progress and EE’s state by geographical area can be identified. Research findings show that certain regions adopt one of the two schools. It should be noted that ESD has become increasingly accepted globally since the decade promoted by UNESCO. Nonetheless, EE has played a more significant role in shaping the history of environmental education in certain regions. Additionally, more literature is needed to discuss the design and revision of economics curricula in the context of ESD. The originality of this paper lies in separating regions that adopt EE from those that adopt ESD, as well as explaining exceptional cases in the context of economic education involving ESD.
Accumulation of Copper (Cu) and Cadmium (Cd) Ions in Settling Basins to Assess the Effectiveness of the IPLT TPA Putri Cempo, Surakarta
Authors: Sunarhadi Amin , Kusumaningrum Lia , Nirwasita Hartono Daiva Ardhania , Naafi Diesta Atha’ul , Sutrisno Muhammad Tri , Mahmudah Umi , Alzahabi Muhammad Adib 
Published: December 2024

Abstract
Decreased water quality is caused by various human activities. One of the most dangerous types of water pollution is heavy metal pollution. Exposure to heavy metals can endanger human health even at low concentrations. One source of heavy metal pollution comes from domestic waste pollution from domestic activities, fecal waste. Fecal sludge contains solids dissolved in water, in the form of a mixture of organic materials and heavy metals, making it hazardous if not treated first before disposal. In this research, the author used water samples from the IPLT TPA Putri Cempo to determine the levels of Copper (Cu) and Cadmium (Cd) and the hazards posed by heavy metals, in order to assess the effectiveness of the Putri Cempo TPA IPLT system. The method used was wastewater sampling from the Putri Cempo landfill final sedimentation tank, sample preparation and analysis with atomic absorption spectrophotometer (AAS). The results of the investigation show that the final pool water at Putri Cempo landfill contains 0.0155 mg/L of copper and -0.0076 mg/L of cadmium, where these results are still below the threshold set by wastewater quality standards in Indonesia.