Hasil untuk "Technical hydraulics"

Shimin Yu, Edward Ransley, Ling Qian et al.

This paper summarises the work conducted within the 1st FOWT (Floating Offshore Wind Turbine) Comparative Study organised by the EPSRC (UK) ‘Extreme loading on FOWTs under complex environmental conditions’ and ‘Collaborative computational project on wave structure interaction (CCP-WSI)’ projects. The hydrodynamic response of a FOWT support structure is simulated with a range of numerical models based on potential theory, Morison equation, Navier-Stokes solvers and hybrid methods coupling different flow solvers. A series of load cases including the static equilibrium tests, free decay tests, operational and extreme focused wave cases are considered for the UMaine VolturnUS-S semi-submersible platform, and the results from 17 contributions are analysed and compared with each other and against the experimental data from a 1:70 scale model test performed in the COAST Laboratory Ocean Basin at the University of Plymouth. It is shown that most numerical models can predict similar results for the heave response, but significant discrepancies exist in the prediction of the surge and pitch responses as well as the mooring line loads. For the extreme focused wave case, while both Navier–Stokes and potential flow base models tend to produce larger errors in terms of the root mean squared error than the operational focused wave case, the Navier-Stokes based models generally perform better. Given the fact that variations in the solutions (sometimes large) also present in the results based the same or similar numerical models, e.g., OpenFOAM, the study highlights uncertainties in setting up a numerical model for complex wave structure interaction simulations such as those involving a FOWT and therefore the importance of proper code validation and verification studies.

Lyudmila V. Kravchenko, Alexander S. Lebedev, Anna E. Khadzhidi et al.

Background.  To evaluate the effect of different irrigation parameters, a model of a sloping slope was developed for experiments, and different irrigation regimes were investigated using a horizontal well simulator. To consider the process of subsurface irrigation were modeled sloping slopes of sand-soil on the laboratory installation of the author's design, implemented at the Department of Hydraulics and Agricultural Water Supply of Kuban State Agricultural University. Based on the analysis of the results of the experiments, a graph showing the trajectory of irrigation water movement when modeling subsurface irrigation using a simulator of horizontal well was obtained for the first time. The obtained results showed that the main flow of irrigation water in the process of its movement has the trajectory of a downward curve, originating directly from the simulator of horizontal well, then passing at an angle the whole considered area of the slope, and ending at its lower boundary. Purpose. Purpose of the study to investigate the effectiveness of subsurface irrigation on sloping slope models using a horizontal well simulator. Materials and methods. Measurement of the indicators of slope angle and soil moisture level were carried out in laboratory conditions, experiments using a simulator of horizontal wells; the method of mathematical modeling was used for the analysis of wetting processes; statistical methods were used for the processing of experimental data. This work is based on the analysis of methods and techniques of irrigation on sloping soil surfaces. To consider the process of subsurface irrigation were modeled sloping slopes of sand-soil on the laboratory installation of the author's design, implemented at the Department of Hydraulics and Agricultural Water Supply of Kuban State Agricultural University. Horizontal well simulators in the form of U-shaped tubes consisting of two vertical parts and one perforated horizontal part were placed in the sand-soil of the author's laboratory installation. A multifactorial experiment was conducted on the experimental laboratory installation to study the technical feasibility of quality irrigation of crops grown on sloping slopes with the help of simulators of horizontal wells equidistantly located down the slope. Results. The data obtained during the laboratory experiment were processed, and on the basis of their analysis the graphs of dependences of water penetration distances on its volumes at angles of inclination to the plane of 10-30 degrees were plotted. Conclusion. Based on the analysis of the results of the experiments, for the first time a graph showing the trajectory of irrigation water movement when modeling subsurface irrigation using a simulator of a horizontal well was obtained, which demonstrated the movement of the main flow of irrigation water, which is the trajectory of a downward curve originating directly from the simulator of a horizontal well, then passing at an angle through the whole slope area under consideration, and ending at its lower boundary. EDN: GTJJBW

Maxim G. Rakhutin, Van Hiep Tran, Alexander E. Krivenko et al.

During the operation of hydraulic excavators, the technical condition of pumps deteriorates due to wear, leading to increased internal clearances, fluid leakage, a reduction in volumetric efficiency, and higher energy losses, ultimately resulting in excessive fuel consumption. The objective of this study was to determine the optimal service life of pumps, taking into account the growing fuel overconsumption during operation. The following tasks were addressed: developing a mathematical model for pump ownership costs, incorporating progressive fuel overconsumption; designing an algorithm and conducting computer simulations using Simulink-Matlab; and assessing the increase in fuel consumption. The study examines the impact of the technical condition of the main hydraulic pumps on fuel overconsumption using the Komatsu PC2000-8 hydraulic excavator as a case study. Based on the proposed pump operation cost model, which accounts for the increase in fuel consumption over time, dependencies between fuel overconsumption and pump wear were established. Computer modeling was performed in Simulink-Matlab and Excel based on the developed calculation methodology and software algorithm. Relationships between the excavator's fuel overconsumption and the technical condition of the pumps were identified. A mathematical model for pump ownership costs is presented, taking into account the progressive fuel overconsumption during operation, along with the resulting equation for determining the optimal service life of pumps to minimize total costs, including pump acquisition and fuel expenses. This expression considers the technical condition of the main pumps, their rate of deterioration, fuel costs, and pump replacement costs. A fuel overconsumption indicator was introduced, defined as the ratio of the difference between actual fuel consumption per 1 m3 of excavated material and fuel consumption at nominal efficiency of the main pumps (nominal fuel consumption) to the nominal fuel consumption. The application of this criterion, in conjunction with the proposed equation for determining the optimal pump service life, allows for a data-driven selection of the critical wear threshold for the main pumps, reducing total ownership and fuel costs by up to 17%, depending on economic and mining-engineering conditions.

Peker İsmail Bilal, Sorman Ali Arda, Cuceloglu Gokhan et al.

This study aims to conduct a comparative analysis of global precipitation products and ground station data using a hydrological model. The effects of different gridded precipitation datasets and topographic model inputs, such as subbasin delineation and elevation band details, on streamflows were investigated. The study focused on the mountainous Nilüfer Basin in Türkiye. Ground station data (GSD) and three different global precipitation datasets —Climate Forecast System Reanalysis (CFSR), Climate Hazards Group InfraRed Precipitation with Station (CHIRPS), and National Aeronautics and Space Administration–Prediction of Worldwide Energy Resources (NASA–POWER)— were used. The Soil and Water Assessment Tool (SWAT) was employed for hydrological modelling and Nash-Sutcliffe Efficiency (NSE) was utilized as the performance criterion for model calibration. The results showed that GSD, CHIRPS, and NASA–POWER achieved reasonable NSE levels (>0.5) without calibration, whereas CFSR performed poorly (NSE<0.2). After calibration, all models indicated successful results (NSE>0.70), with a notable improvement in CFSR (NSE increased from 0.12 to 0.71). Increasing the number of subbasins slightly improved the results, with the highest change in NSE of 0.09. Generating too many subbasins, though, lead to longer processing times without further improvements. However, introducing elevation bands significantly enhanced model performance (NSE increased by 0.21–0.27 across all datasets). An increase in the number of bands yielded only slight improvements, with NSE increasing by 0.03 at most.

Peijun Li, Chen Hao, Ning Xu et al.

The core physical behavior of reactors is essentially the result of multi-physical fields coupling feedback. High-fidelity neutronics/thermal-hydraulics (N/TH) analysis can simulate and predict nuclear reactor core phenomena realistically, providing advanced and reliable technical means during the design and safety analysis of nuclear reactor. In this work, an efficient and robustness coupling method using power density as the coupling parameter, Matrix-Free Newton Krylov (MFNK) method, is successfully developed and innovatively implemented in HNET for high-fidelity N/TH coupling simulation. To enhance the efficiency and stability, the multi-level generalized equivalence theory-based CMFD (ML-gCMFD) iterative acceleration method and ML-gCMFD coupling acceleration method are proposed. In addition, the nonlinear preconditioning and hybrid perturbation size formula are implemented to further improve the convergence. Finally, to evaluate the numerical accuracy, convergence, efficiency and stability of MFNK method, a series of representative problems, including a three-dimensional (3D) single fuel pin problem, VERA Benchmark Problem 6, and VERA Benchmark Problem 7, are analyzed by comparing with the current N/TH coupling methods. Numerical results indicate that MFNK method can obtain strong stability, high convergence performance, and relatively high computational efficiency while ensuring high accuracy. It demonstrates that MFNK method has significant performance advantages and potential for high-fidelity N/TH coupling simulation.

T. N. Postnikova, O. O. Rybak, A. S. Gubanov et al.

This study fills a gap in the long-term prediction of changes in parameters of the Elbrus glaciers, using the GloGEMflow-debris model to simulate the glacier evolution. The part 1 provides a detailed description of the model architecture. The model consists of three blocks in which the calculation of the surface mass balance, glacier flow and moraine transformation is carried out. The area and thickness of the moraine cover increase as glaciers degrade. This is important to consider, as a thicker layer of moraine reduces the ice melting. For predictive calculations, the data on temperature and precipitation for five SSP climate scenarios are taken from the CMIP6 project. A temperature index method is used to calculate the surface mass balance, taking into account the influence of the moraine cover: the ablation of pure ice is adjusted in accordance with the area and thickness of the moraine cover. The ice flow block is used to update the geometry of glaciers and moraine cover. The adaptation of the model to the glaciers of Elbrus includes the adjustment of the block of the moraine cover evolution, which corresponds to the geological features of the region. Thus, the accumulation of moraine on the glaciers of the volcanic peak through erosion of slopes and landslides can be neglected, it is considered to be the bottom moraine, thrown up along the shear planes, the main source of surface moraine on the glaciers of Elbrus. Hence, the debris-cover source in the model is specified to be the result of bedrock erosion rather than slope erosion. The paper discusses calibration processes that allow using simple modeling methods, such as the temperature index method for calculating the surface mass balance, and to simulate the real behavior of glaciers. Despite the fact that the validation of the model revealed a slight underestimation of mass loss at the beginning of the XXI century, the general patterns of mass loss are reproduced correctly, although the energy balance has not been explicitly described. Thus, the adjustment of the model ensures its adaptation to the glaciation conditions on Elbrus.

Eyyup Ensar Başakın, Paul C. Stoy, Mehmet Cüneyd Demirel et al.

We developed a combined drought index to better monitor agricultural drought events. To develop the index, different combinations of the temperature condition index, precipitation condition index, vegetation condition index, soil moisture condition index, gross primary productivity, and normalized difference water index were used to obtain a single drought severity index. To obtain more effective results, a mesoscale hydrologic model was used to obtain soil moisture values. The SHapley Additive exPlanations (SHAP) algorithm was used to calculate the weights for the combined index. To provide input to the SHAP model, crop yield was predicted using a machine learning model, with the training set yielding a correlation coefficient (R) of 0.8, while the test set values were calculated to be 0.68. The representativeness of the new index in drought situations was compared with established indices, including the Standardized Precipitation-Evapotranspiration Index (SPEI) and the Self-Calibrated Palmer Drought Severity Index (scPDSI). The index showed the highest correlation with an R-value of 0.82, followed by the SPEI with 0.7 and scPDSI with 0.48. This study contributes a different perspective for effective detection of agricultural drought events. The integration of an increased volume of data from remote sensing systems with technological advances could facilitate the development of significantly more efficient agricultural drought monitoring systems.

Felix Alan Aguilar Carrera

Benjamin Wee Keong Ang, Chen-Hua Yeow, Jeong Hoon Lim

In recent years, the advent of soft robotics has changed the landscape of wearable technologies. Soft robots are highly compliant and malleable, thus ensuring safe human-machine interactions. To date, a wide variety of actuation mechanisms have been studied and adopted into a multitude of soft wearables for use in clinical practice, such as assistive devices and rehabilitation modalities. Much research effort has been put into improving their technical performance and establishing the ideal indications for which rigid exoskeletons would play a limited role. However, despite having achieved many feats over the past decade, soft wearable technologies have not been extensively investigated from the perspective of user adoption. Most scholarly reviews of soft wearables have focused on the perspective of service providers such as developers, manufacturers, or clinicians, but few have scrutinized the factors affecting adoption and user experience. Hence, this would pose a good opportunity to gain insight into the current practice of soft robotics from a user’s perspective. This review aims to provide a broad overview of the different types of soft wearables and identify the factors that hinder the adoption of soft robotics. In this paper, a systematic literature search using terms such as “soft”, “robot”, “wearable”, and “exoskeleton” was conducted according to PRISMA guidelines to include peer-reviewed publications between 2012 and 2022. The soft robotics were classified according to their actuation mechanisms into motor-driven tendon cables, pneumatics, hydraulics, shape memory alloys, and polyvinyl chloride muscles, and their pros and cons were discussed. The identified factors affecting user adoption include design, availability of materials, durability, modeling and control, artificial intelligence augmentation, standardized evaluation criteria, public perception related to perceived utility, ease of use, and aesthetics. The critical areas for improvement and future research directions to increase adoption of soft wearables have also been highlighted.

Jeny Alihut Ventura Gutiérrez

La investigación sobre el aprovechamiento del estiércol bovino para la producción de biogás fue realizada entre los meses de octubre de 2010 a marzo de 2011. Se seleccionó la Planta Piloto de Tratamiento de Aguas Residuales Aurora II, “Ing. Arturo Pazos” como lugar de la investigación. Se estudiaron y analizaron los diferentes tipos de biodigestores y se optó por el biodigestor tubular de polietileno por ser el más adecuado para llevar a cabo la investigación. Se diseñó un biodigestor de 5 m de largo y 1,20 m de diámetro para una carga diaria de 18,90 kg de mezcla (estiércol más agua), luego de instalarlo, se puso en marcha. La producción de biogás proyectada fue de 0,61 m3 por día encontrándose que había una producción extra de 0,37 m3 por día. Se analizaron ciertas variables que influyen en la producción de biogás como la temperatura, contenido de sólidos, nutrientes, relación carbono/nitrógeno y el pH. Se encontró que las variables mencionadas interfieren directamente en la producción diaria de biogás y que deben monitorearse periódicamente. El proceso de digestión anaerobia que ocurre dentro de un biodigestor deja como residuo un biofertilizante pero en este caso se encontró que aunque el efluente no se puede considerar como biofertilizante por ser pobre en su contenido de nutrientes, si es una fuente natural de aporte de nutrientes a los suelos.

Pedro Saravia Celis, Julián Antonio Duarte

La Escuela Regional de Ingeniería Sanitaria y Recursos Hidráulicos (Eris), ha sido la encargada de la implementación de los programas de las maestrías de Ingeniería Sanitaria y la maestría de Recursos Hidráulicos. Las maestrías funcionan como un todo al amparo de la escuela.   La Escuela desde su fundación en 1,964 ha tenido como propósito la búsqueda de la excelencia académica en la formación integral de los profesionales que estudian en ella. Esto incluye la búsqueda de un fuerte compromiso ético y moral en la actuación de los egresados en la propuesta de soluciones a los problemas regionales y nacionales. La escuela se ha esforzado por ser un espacio donde se desarrolle el pensamiento crítico y la solidaridad humana. Desde su creación la Eris ha tenido la categoría de regional como lo estableció el Consejos Superior Universitario Centroamericano, CSUCA. La escuela pertenece a la Facultad de Ingeniería de la Universidad de San Carlos de Guatemala y fue la primera maestría creada en la Universidad.   La escuela ha formado más de 500 maestros en ciencias de Ingeniería Sanitaria y Recursos Hidráulicos. Los egresados son de diversos países como El Salvador, Honduras, Nicaragua, Costa Rica, Panamá, Colombia, Bolivia, Perú y principalmente Guatemala. En materia de investigación ha aportado más de 390 estudios especiales (tesis de investigación), en diferentes áreas de las ciencias que incluyen aguas residuales, agua para consumo humano, residuos sólidos, saneamiento ambiental, calidad del aire, limnología, hidrología, aguas subterráneas, potamología, entre otras.   A lo largo de su vida académica la Eris ha recibido varios reconocimientos y tenido el apoyo de varias organizaciones internacionales para el otorgamiento de becas a profesionales centroamericanos para cursar las maestrías ofrecidas. Además, la escuela tiene convenios estratégicos de cooperación firmados con varias instituciones nacionales e internacionales.   La escuela siempre ha contado con el apoyo y respaldo de la Facultad de Ingeniería y la Universidad de San Carlos. Lo que la escuela es hoy en día ha sido gracias a la contribución de varias generaciones de profesionales nacionales e internacionales, por lo tanto, queremos dejar constancia de agradecimiento a todas y cada una de ellas por sus aportes.   Finalmente dejar constancia de reconocimiento al Ingeniero Guillermo Guzmán Chinchilla (QEPD) y Zoilita Márquez porque fueron los primeros que comenzaron con el proceso de sistematización de la historia de la Eris.

Jorge Mauricio Pontaza Pivaral

Este articulo trata sobre la eficiencia de los Microorganismos Efectivos (ME) al aplicarlos en la planta de tratamiento de aguas residuales San Cristóbal, colonia Panorama, Mixco, Guatemala. Para esto, se llevó a cabo la toma de 20 muestras compuestas en la entrada y salida de la misma, entre los meses de junio a septiembre de 2011. Dicha planta de tratamiento tenía una eficiencia en remoción de materia orgánica de 29,53 % y al aplicar los microorganismos se obtuvo un aumento de 19,07 %. El valor de los microorganismos representa un 14,93 % de la operación y mantenimiento anual, este porcentaje es menor al aumento de la eficiencia, por lo tanto, es factible la implementación de Microorganismos Efectivos (ME) al agua residual. Se debe tomar en consideración que actualmente ingresa un caudal de 20 l/s; y esta fue diseñada para tratar un caudal de 4,83 l/s, por lo que, existe un caudal excedente del 75,85%, de no ser así, la eficiencia podría ser mayor.  

Wilder Eduardo González Raxjal

El uso de modelos numéricos del tiempo es una herramienta vital para todo Servicio Meteorológico Nacional. El modelo de Investigación y Pronóstico del Tiempo (WRF, por sus siglas en inglés) es un modelo numérico meteorológico que en este estudio se utiliza como herramienta para estimación de caudales utilizando su lluvia pronosticada. En este estudio se hace énfasis en la importancia que tiene el uso de los modelos numéricos meteorológicos como herramientas en la hidrología, principalmente aplicado a cuencas que presentan registros de inundaciones que causan severos daños a la población que se ubica en ellas, tal es el caso del río Cabuz de Guatemala, donde se aplica este estudio.  Se espera que esta primera aproximación del modelo permita implementar en un futuro sistemas de alerta temprana que colaboren con la reducción de desastres en la cuenca del río Cabuz. En este estudio se utilizó un modelo meteorológico y uno hidrológico para realizar un análisis de lluvia-escorrentía. Se seleccionaron ocho eventos de lluvias intensas del 2010 para calibrar la cuenca utilizando la metodología del hidrograma unitario sintético del SCS. Se modelaron los eventos de lluvia seleccionada del 2014 utilizando como base las condiciones de calibración de la cuenca. Los resultados muestran que los hidrogramas de lluvia pronosticada por el modelo WRF y la lluvia registrada tuvieron variaciones significativas, las cuales se atribuyen a la resolución utilizada en el modelo o a la influencia que puede generar la retención potencial inicial en la cuenca, por lo que se recomienda profundizar estudios en estos dos aspectos para reducir estas diferencias encontradas.

Roberto Basili, Beatriz Brizuela, André Herrero et al.

The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models’ weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH &gt;5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH &gt;3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH &gt;1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning.

Jackson Tellez-Alvarez, Manuel Gómez, Beniamino Russo et al.

Numerical models concerning inlet systems are run to assess the hydraulic performance of existing or new systems and estimate the flow interchanges between the surface overland and sewer flows. In most programs, these interactions are modelled using the orifice equation, with estimated discharge coefficients around 0.6. In this paper, discharge values and energy loss coefficients for several pressurized grated inlets were obtained by experimental and numerical approaches and compared. To achieve these goals, a numerical model replicating several experimental tests carried out at the hydraulic laboratory of Universitat Politècnica de Catalunya (UPC) was produced using a CFD model (Flow 3D). This numerical model was found to be highly sensitive to the mesh size used; however, it was able to accurately simulate the experimental processes. The comparison considered different combinations of pressurized flow though the grate, between 10 to 50 l/s, and different longitudinal gradients. The experimental discharge coefficient was found to increase with surcharging flowrate (ranging from 0.14 and 0.41), whereas the longitudinal gradient was found to have no effect. The discharge coefficients obtained in this study show that the standard 0.6 value commonly used by practitioners should be revised to a range between 0.14 to 0.41, depending on circulating flow and inlet type. In addition, the loss coefficient values range from 0.25 to 3.41.

Jenica CĂLINA, Aurel CĂLINA

This paper presents in a rigorous and practical manner the way of developing and implementing a GIS, in which surveyed data is processed and the final results that contribute to the analysis and solving issues that arise on a day, to day basis, in the uninterrupted process of using a drinking water supply network, in order to improve its efficiency and the quality of the services. Using GIS software, maps and other cartographic data can be introduced into the system. Afterwards, the data can be stored for long periods of time, accessed at any point and easily analysed. With the tools made available by the GIS software, the datasets can be processed and new relevant information can be extracted which can be designed and printed as new maps. Such a system is truly a transformative ensemble of software because it has the power of changing the way decisions are made in a agricultural company, or anywhere in the world. In the field of hydraulics where it shall be used, it has been proven that the use of a GIS allows for a better and more detailed understanding of the water network and the way various network elements interact with each other. For an improved management of the water network, it is possible to also add to the database details regarding the quality and quantity of delivered water in a certain region. This makes merging all of the information in one system very important. All this precise information will improve the efficiency from a technical standpoint and also from an administrative one which will result in higher quality services for the customers.

Dawid Szurgacz, Sergey Zhironkin, Stefan Vöth et al.

The paper discusses the results of a study carried out to determine the thermal condition of a conveyor power unit using a thermal imaging camera. The tests covered conveyors in the main haulage system carrying coal from a longwall. The measurements were taken with a thermal imaging diagnostic method which measures infrared radiation emitted by an object. This technology provides a means of assessing the imminence and severity of a possible failure or damage. The method is a non-contact measuring technique and offers great advantages in an underground mine. The thermograms were analysed by comparing the temperature distribution. An analysis of the operating time of the conveyors was also carried out and the causes of the thermal condition were determined. The main purpose of the research was to detect changes in thermal state during the operation of a belt conveyor that could indicate failure and permit early maintenance and eliminate the chance of a fire. The article also discusses the construction and principle of operation of a thermal imaging camera. The findings obtained from the research analysis on determining the thermal condition of the conveyor drive unit are a valuable source of information for the mine’s maintenance service.

M. Allaf, Senem Şentürk Lüle, Ü. Çolak

Abstract This work presents the development of indigenous code TM2-RIA for steady-state and transient analyses of TRIGA type research reactor at Istanbul Technical University Energy Institute. The 2-dimensional code adapts piecewise constant function for solving point kinetics equation linked with thermal–hydraulic equations for cylindrical fuel type. TM2-RIA provides flexibility of implementing different delayed neutron parameters, it also offers different thermal-hydraulics structure options (number of channels and control volumes). The code is tested against the experimental data and calculations of EUREKA-2/RR code. Considering many experimental uncertainties, the TM2-RIA 5-channels model agrees acceptably with the steady-state experimental results. In the transient analyses, three pulsing scenarios are investigated, based on the results, the code has performed differently with different neutronic sets and thermal-hydraulics structures. That indicates how the reactor kinetics is being influenced by the differences in the recorded thermal history, and it shouldn’t be neglected even for small deviation. Besides, the constant overestimation of the fuel temperatures implies the need for modelling the heat sink induced by central Zirconium rod in fuel element and investigating its effect. That being said, the code agrees fairly well in many cases corresponding to those changes, when it predicts the peak power and fuel centerline temperature. Moreover, the gap between the experimental and the numerical results for the fuel temperature gets smaller with the increase of the pulsing reactivity. Another promising aspect is that the adapted point kinetics approach shows similar performance, in comparison with the common Cohen’s approach used by EUREKA-2/RR, while providing relative simplicity in developing and implementing the TM2-RIA code.

Marin M. Kress, B. Tetreault, K. Mitchell et al.

PURPOSE: This Coastal and Hydraulics Engineering Technical Note (CHETN) presents examples of Automatic Identification System (AIS) data and capabilities used to support real-time operations, assist in incident investigations, and contribute to waterways usage analysis projects for a variety of infrastructure management needs across the US Army Corps of Engineers (USACE). These case study presentations serve as examples for those who are new to AIS technology or navigation infrastructure operations.

Suryadimal, Ganefri, Ambiyar et al.

This study aims to identify technical and non-technical aspects in developing the feasibility assessment of community-based hydropower.The technical aspects consist of the aspects of Hydrology, Civil and Mechanical Electrical and non-technical aspects influenced by economic, socio-cultural and environmental aspects. In identifying the two aspects above exploration of Borg and Gall theory, and related studies in the feasibility assessment commonly used by a team of experts and technical consultants and government standards.The feasibility assessment is strongly influenced by 43.24% of technical and non-technical aspects, the relationship between hydraulics and economic aspects ranges 32.43%, and the influence of social and environmental aspects by 24.32%