Hasil untuk "Technical hydraulics"

Alexey N. Beskopylny, Denis Medvedev, Vyacheslav Grishchenko et al.

Current trends in the development of technology are linked inextricably to the increasing level of automation in technological processes and production systems. In this regard, the development of systems for supplying working fluids with adjustable pumps that have high performance characteristics, an increased service life and low operating costs is an important scientific and technical task. A primary challenge in the development of such systems lies in achieving low fluid flow rates while maintaining stable operating characteristics. This challenge stems from the fact that currently available controlled hydraulic pumps exhibit either a high cost or suboptimal life and efficiency parameters. This work focuses on the development of a plunger hydraulic pump with a small working volume. A mathematical model has been developed to investigate the characteristics, optimize the design of this pump and further expand the size range of such pumps. The solution was implemented on a computer using the dynamic modelling environment MATLAB/Simulink. In order to verify the mathematical model’s adequacy, a plunger pump prototype was built and integrated with a test bench featuring a measurement system. The test results showed higher pump efficiency and a significant reduction in hydraulic losses. An analysis of the obtained data shows that the pump is characterized by increased efficiency due to optimal flow distribution and reduced internal leakage, which makes it promising for use in hydraulic systems requiring improved operating characteristics. The developed pump has more rational characteristics compared to existing alternatives for use in water supply systems for induction superheaters. The experimental external characteristics of the developed pump are 10% higher than the external characteristics of the ULKA EX5 pump selected as an analogue, and the pressure characteristics are 65% higher. It offers production costs that are several times lower compared to existing cam-type plunger or diaphragm pumps with oil sumps and precision valve mechanisms. Additionally, it has significantly better operating characteristics and a longer service life compared to vibrating plunger pumps.

Sourav Dutta, Anna Wagner, Theadora Hall et al.

This US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory engineering technical note (CHETN) documents a preliminary study on the use of specialized machine learning (ML) methods to model the variations in groundwater level (GWL) with time. This approach uses historical groundwater observation data at seven gage locations in Wyoming, USA, available from the USGS database and historical data on several relevant meteorological variables obtained from the ERA5 reanalysis dataset produced by the Copernicus Climate Change Service (usually referred to as C3S) at the European Center for Medium-Range Weather Forecasts to predict future GWL values for a desired period of time. The results presented in this report indicate that the ML method has the potential to predict both short-term (4-hourly) as well as daily variations in GWL several days into the future for the chosen study region, thus alleviating the need for employing sophisticated process-based numerical models with complicated model structure configurations.

Brian J. Tetreault, G. W. Johnson, Kevin Kohlmann et al.

The purpose of this Coastal and Hydraulics Engineering technical note (CHETN) is to discuss the concept, demonstrations, and the initial results of multiyear proof-of-concept testing of the capability to share weather data from ships via the Automatic Identification System (AIS). Technical foundations of this process were described by Tetreault and Johnson (2020) with partial results described in Johnston et al. 2021. The updated results in this CHETN include evaluation of the efficacy of the various application-specific message (ASM) formats use to communicate the weather observations and data reception results for selected vessels that have been participating in the proof-of-concept field deployment since 2019 or later.

R. Bergua, W. Wiley, A. Robertson et al.

<p>This paper provides a summary of the work done within Phase IV of the Offshore Code Comparison Collaboration, Continued with Correlation and unCertainty (OC6) project, under International Energy Agency Wind Technology Collaboration Programme Task 30. This phase focused on validating the loading on and motion of a novel floating offshore wind system. Numerical models of a 3.6 MW horizontal-axis wind turbine atop the TetraSpar floating support structure were compared using measurement data from a <span class="inline-formula">1:43</span>-Froude-scale test performed in the University of Maine's Alfond Wind–Wave (W2) Ocean Engineering Laboratory. Participants in the project ran a series of simulations, including system equilibrium, surge offsets, free-decay tests, wind-only conditions, wave-only conditions, and a combination of wind and wave conditions. Validation of the models was performed by comparing the aerodynamic loading, floating support structure motion, tower base loading,<span id="page1026"/> mooring line tensions, and keel line tensions. The results show a relatively good estimation of the aerodynamic loading and a reasonable estimation of the platform motion and tower base fore–aft bending moment. However, there is a significant dispersion in the dynamic loading for the upwind mooring line. Very good agreement was observed between most of the numerical models and the experiment for the keel line tensions.</p>

Roberto Barragan Monrroy, Marco Antonio Constantine Macias, Betty González Osorio et al.

El propósito de la presente investigación consistió en determinar las cantidades de cadmio y plomo presentes en muestras de soya (Glycine max L) recolectadas en el cantón Mocache, Ecuador. Se tomaron muestras de cuatro tiendas de alimento y una plantación durante los meses de febrero, marzo y abril. Utilizando la espectrometría de absorción con llama y el método "NMLK-AOAC 999.11" en un espectrómetro Perkin Elmer HGA-500, se determinaron concentraciones promedio de 0,22 ± 0,37 mg/kg y 0,21 ± 0,03 mg/kg para cadmio y plomo respectivamente. Estas cifras excedieron los límites máximos permitidos según las normativas internacionales. Los resultados resaltan una preocupante situación de seguridad alimentaria en la localidad, subrayando la urgencia de implementar estrategias efectivas de gestión y control de metales tóxicos en la producción y comercialización de soya.

Roberto Johan Barragán Monrroy, María Fernanda Reinoso Triana, Cecilia Carolina Tay-Hing Cajas et al.

Las emisiones de metano en la ganadería son generadas principalmente por la descomposición del estiércol almacenado o tratado, y aunque este en pequeñas cantidades no es tóxico, una exposición a largo plazo puede generar efectos negativos. La investigación aborda la necesidad de optimizar el proceso de conversión de estiércol bovino en biogás para reducir y aprovechar las emisiones de metano como fuente de energía limpia. El objetivo principal fue realizar un análisis de las deyecciones bovinas de la hacienda ganadera La Estrella para generar biogás utilizando un biodigestor piloto tipo batch. Se empleó un tanque de 208 l y se ocupó el 75% de su capacidad (156 l de estiércol + agua), se adaptó un higrómetro digital para medir la variación de temperatura y humedad interna, se monitorizó el metano con un equipo de gases GD, se calculó la cantidad de energía liberada, y se realizaron análisis en laboratorio del pH, sólidos totales, volátiles y fijos con el propósito de evaluar el comportamiento de las variables durante el tiempo de retención (1 mes). Los resultados mostraron una temperatura promedio de 40.6°C, humedad del 96.1%, concentración de metano de 23,696 ppm, pH de 7.01 y contenidos de ST 15%, STV 5.81% y STF 9.66%, mismos que indicaron un correcto funcionamiento del biodigestor en cuanto a la calidad de producción de biogás. Se concluye que la investigación cumplió con los requisitos para el proceso anaeróbico y la obtención de metano.

Vladyslav Ponomarov

The article discusses digital hydraulic valves, which are an innovative alternative to traditional proportional analog valves. Digital hydraulics utilize a combination of simple, reliable, and inexpensive ON/OFF type valves, offering high precision in flow and pressure control through programmable logic controllers. The main advantage of such systems is the reduction in energy consumption, as they eliminate the need for constant pump operation and have no internal leakage. The article highlights the economic benefits of digital valves, including lower initial investments due to their lower cost compared to proportional counterparts. Importantly, if one valve fails, the system remains operational, as the failure of individual components does not critically affect overall performance. Special attention is given to coding schemes and control methods, particularly binary coding and pulse number modulation. Binary coding allows for significantly improved regulation accuracy with a minimal number of valves and ensures system fault tolerance. The use of parallel-connected valves, which offer a wide range of states, allows precise control of flows and pressures without the need for switching after the desired positions are set. Additionally, digital hydraulic systems provide fast response times and precise control, making them effective for various industrial applications. Further research in this area could lead to the development of new technological solutions and broader implementation in the industry. The article also covers the technical aspects of such systems, particularly pulse-width modulation, the most common approach to controlling two-way valves. PWM achieves high regulation accuracy through frequency modulation, although low switching frequencies may cause pressure pulsations, which must be compensated through specialized system design or damping devices. In conclusion, digital hydraulic valves represent a promising solution for increasing the efficiency and reliability of hydraulic systems in modern industries, with the potential for significant reductions in energy consumption and operational costs.

Shannon Brown, R. Fischer, N. Spore et al.

The goal of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to document initial results to derive topography on the beachface in the northern Outer Banks, North Carolina, utilizing Planet Labs’ SkySat stereo panchromatic imagery processed in Agisoft Metashape. This technical note will provide an initial evaluation into whether Planet Lab’s SkySat imagery is a suitable image source for satellite Structure from Motion (SfM) algorithms as well as whether these data should be explored as a federal beach project monitoring tool. Depending on required accuracy, these data have the potential to aid coastal scientists, managers, and US Army Corps of Engineers (USACE) engineers in understanding the now-state of their coastlines and employ cost-effective adaptive management techniques.

Kenneth Swan, James Kilroy, Brady Towne et al.

This Dredging Operations Technical Support (DOTS) Program technical note presents the results of a study undertaken by the Navigation Branch, US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL), at the request from the Louisville District (LRL) to examine an incident involving a single vessel and structure in a high-water condition. The vessel-position data used in this request were broadcast from an onboard Automatic Identification System (AIS) transceiver and received by US Army Corps of Engineers (USACE)–owned Lock Operations Management Application (LOMA) tower sites located along the Ohio River.

Hans VanSumeren, J. Lutchko

Globally, the needs and requirements of marine technicians from decades past are significantly different from the skills and competencies of today's workforce. In the past, the typical “technician” for the industry came from trade focused skills including electronics and hydraulics or a technical trade focused two-year associates degrees from community colleges. Supporting today's technical marine based workforce requires agile approaches and a shift from traditional knowledge transfer to a competency-based approach that needs to adapt to diverse learner profiles and backgrounds.

D. Anderson, Crystal Painter, Annika O’Dea et al.

This Coastal and Hydraulics Engineering Technical Note (CHETN) presents the development of a workflow to process Planet SkySat videos collected from space at the US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL), Field Research Facility (FRF), in Duck, North Carolina, to derive wave kinematics and perform bathymetric inversions. The document summarizes the nine 30–60 s* satellite video collections, demonstrates the accuracy of an automated rectification and stabilization workflow, and applies a new short-dwell version of a common inversion algorithm (cBathy) to demonstrate the utility of short-dwell videos from space providing an initial out-of-the-box assessment of errors for one of the collections, and recommends future avenues of research for improving bathymetric predictions.

Kenneth Swan, James Kilroy, Brady Towne et al.

This Coastal and Hydraulics Engineering Technical Note (CHETN) presents the effects on the reception of radio signals due to increasing the antenna height at Tom Bevill Lock and Dam (L&D) in Pickensville, Alabama. The signals are received Automatic Identification System (AIS) broadcasts from commercial vessels operating along the Tennessee-Tombigbee Waterway. These AIS broadcasts are received by the Lock Operations Management Application (LOMA) radio equipment at Tom Bevill L&D.

Andrew Griffith, E. Hammack, J. Hite

The US Army Engineer Research and Development Center (ERDC) has begun an investigation of the load conditions experienced by a traveling kevel when moored to a moving barge train. These traveling kevel systems are essential for the safe and efficient use of the US Army Corps of Engineers (USACE) navigation lock inventory. This work is being conducted as part of the Navigation Systems Research Program of the Coastal and Hydraulics Laboratory (CHL). Recent failures of traveling kevels suggest that the existing design guidance for design loads for traveling kevels may need updating. This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the pertinent background information and the current issues related to previous traveling kevel failures.

Chaoyu Chen, Qingbiao Zhan

With the scarcity of water resources in various regions, the pressure on water supply projects is also increasing, which has led to a sharp increase in the water hammer effect in water supply pump projects. In response to this issue, the study proposes to apply a unidirectional pressure regulating tower based on mechanical hydraulic technology to water hammer protection in water supply pumps. In addition, the study also optimizes the calculation method of water hammer and designs one simulation software, which is used to simulate and analyze the proposed water hammer protection measures. The study first determines through simulation software that the optimal initial water level of the unidirectional pressure regulating tower is 2m and the optimal diameter of the make-up water pipe is 600 mm. Afterwards, simulation analysis is conducted on different water hammer protection measures, and it is found that the maximum pressure of the water hammer under the proposed protection measures is the lowest, at 14.8m, which was lower than the comparison measures. In addition, according to expert ratings, the average protective effect rating of protective measure 1 by relevant technical personnel is 9.4 points, which is better than the comparative measure. The above results indicate that through the simulation analysis of hydraulic transition process based on mechanical hydraulics, it can be found that the water hammer protection measures proposed in the study have good protective functions and can effectively reduce the water hammer effect in water supply engineering.

John D. Bess, Patrick Blaise, Oliver Buss et al.

A myriad of opportunities is available to collaborate via international benchmark exercises and experimental data preservation activities. Many such opportunities abound under the auspices of the Nuclear Science Committee of the Organisation for Economic Co-operation and Development Nuclear Energy Agency (NEA). Key projects and activities of relevance to the development of advanced reactors design include the International Criticality Safety Benchmark Evaluation Project (ICSBEP), the International Reactor Physics Experiment Evaluation Project (IRPhEP), the International Assay Data of Spent Nuclear Fuel Database (SFCOMPO), the Shielding Integral Benchmark and Archive Database (SINBAD), and The International Experimental Thermal HYdraulicS Database (TIETHYS), and various cooperative benchmark exercises. Interested participants are encouraged to contact the leadership and secretariat of the various Technical Working Groups and Working Parties to become more engaged. This paper provides a summary of the current benchmark exercises and experimental databases available for international participation.

Jules Ramona

Until recently, work on the ancient hydraulics of Lyon had essentially focused on the upper city. Although the existence of a pressurised water system in the lower city was suspected, no synthesis had been conducted on the subject. Drawing on a comprehensive collection of data relating to water-related structures (wells, pipes, basins and fountains), the objective of the article is to review the state of knowledge about the modes of water supply on the slopes of the Croix-Rousse and the Presqu’île. In spite of the restrictive conditions of human settlement on the alluvial terrace, the study area offers significant and diverse aquifer potential which has been exploited since the earliest days of occupation.The wells, connected to the Croix-Rousse catchment galleries or to the ground-water tables of the Presqu’île, were widely used throughout the Ancient period. They are quite similar, generally circular and lined with local stones, with a diameter of between 0.60 and 1.20 m. Sometimes their identification is lacking. They can therefore be interpreted as drainage structures, such as sumps, generally associated with artisanal activities. Probably an addition to rainwater resources, they seem to be non-uniformly distributed over the study area.A little later, perhaps from the end of the 1st century AD, the presence of a public pressurised water supply system suggests that the lower city was no longer just a sanitised alluvial wasteland, punctuated by a few buildings constructed of light materials, but a planned and densely populated permanent urban space. Sections of pipe are thus observed in situ, outside the large domus on the slopes of the Croix-Rousse (ZAC Saint-Vincent) and in the north and centre of the Presqu’île (Îlot Vieille Monnaie, Hôtel-Dieu), or in the direct vicinity of the presumed location of a public fountain (Place d’Albon). As is often the case, lead pipes are missing. Having been systematically removed and reused, they can only be found in a secondary context. However, the discovery of a flanged lead pipe in situ on the Hôtel-Dieu site is an exception. It is also demonstrates for the first time in Lyon the existence of a hybrid lead-wood adduction system.The frequent presence of metal sockets under the outdoor spaces prompts us to consider the widespread use of this type of water supply in a public context. Similarly, the two long clay pipes recently uncovered on the Hôtel-Dieu and Saint-Antoine parking sites are probably linked with an outdoor space. They may have been used, during the same periods, in addition to wooden pipes. However, the nature of their relationship (parallel or hierarchical?) needs to be clarified. Dedicated to thermal activities or to the supply of fountains, the presence of a forced water system suggests the existence of an imposing and complex public supply system.Lastly, the analysis of the hydraulic installations of use can be used to attempt a classification according to supply modes. The study sector thus includes a large number of ponds, probably fed by rainwater (mainly handicraft ponds and outdoor ornamental ponds). There are few devices that we can be sure were supplied with forced clean water. The thermal complexes of the old Monnaie block and of ZAC Saint-Vincent, as well as the public fountain on Place d’Albon are part of it.Ultimately, the study tells us that all the resources available on the zone were directly and efficiently exploited, whether in public, housing or artisanal contexts. Technically difficult to implement, the forced clean water supply and its public character raise questions. While the existence of this system is clearly attested on the slopes of the Croix-Rousse at least from the Claudian period, and from the Flavian period in the north and centre of the Presqu’île, the origin of its water sources, the technical conditions of its operation and the limits of its geographical scope remain speculative. We believe that the source of the network’s supply could be the catchment galleries. Hence, the water would arrive via a main supply network and would then be distributed to the various districts of the lower town by means of distribution tanks, supplemented by a secondary system made up of smaller diameter pipes. Deployed in the lower part of the city, the network might have been lined with secondary water towers such as those observed in Pompeii. Moreover, the absence of evidence of forced water pipes in the southern part of the Peninsula could be attributable to a technical geographical limit on the distribution of water under pressure. In fact, this sector is characterised by a large number of wells. The filling of one of these wells delivered a rare surviving example of a wooden hydraulic pump. In the absence of a pressurised water system, the hypothesis of a complementary water supply for this sector is seems plausible.

Adis Salinas Salinas

El crecimiento demográfico y la expansión industrial han llevado a la producción de volúmenes cada vez mayores de aguas residuales y han ampliado la demanda de métodos sostenibles para su tratamiento y disposición final. El proceso de hidrolisis térmica (THP) ha sido uno de los métodos que se ha desarrollado con el fin de mejorar el manejo de los lodos producidos durante el tratamiento de las aguas residuales. La ciudad de Panamá ha implementado este proceso en el segundo módulo de la planta de tratamiento de agua residual (PTAR). La función del proceso de hidrolisis térmica es hacer que las paredes celulares se rompan bajo el efecto de la alta temperatura y presión, dando como resultado un producto altamente solubilizado que es fácilmente biodegradable. En esta investigación se analizaron en laboratorio los parámetros físicos y químicos correspondientes a un número de muestras tomadas directamente de esta planta, con el objetivo de medir la influencia que tiene la THP en la calidad de los lodos orgánicos. Estos resultados mostraron una significativa influencia del proceso THP en los lodos, encontrando una disminución del 40 al 60 por ciento de solidos volátiles, este resultado evidencia un lodo de mejor calidad y menos volumen generado, pudiendo aprovecharse este en uso agrícola, entre otros usos posibles.

Jeanny Elizabeth de Leon Rios

Este estudio compara la eficiencia de dos filtros artesanales, usando materiales disponibles en áreas rurales con ausencia de sistema de drenaje, lo que obliga tratar las aguas grises para evitar contaminación. Entonces, el objetivo fue determinar la eficiencia de los filtros en función al tipo de material filtrante, siendo estos: 1) arena, grava, carbón activado, viruta de pino verde; y 2) estopa de coco. La eficiencia de estos se determinó a partir de la medición de la demanda química de oxígeno (DQO), demanda bioquímica de oxígeno (DBO), nitritos, nitratos, fosfatos, color aparente, color real, sólido suspendido, y turbidez en afluente y efluente del filtro. Para este estudio, los filtros se construyeron en una comunidad ubicada en El Paraje de Choquixcabel del municipio de Santa Lucía Utatlán departamento de Sololá, Guatemala.  Durante la evaluación se utilizó aguas grises generadas por el lavado de ropa y el agua de la ducha. Durante el estudio se recogieron un total de 12 muestras de afluentes y efluentes. El filtro que presentó mayor eficiencia al 75% en la remoción de parámetros físicos, inorgánicos no metales y orgánicos agregados, fue el de lecho filtrante de viruta de pino verde, aunque su comportamiento no fue constante. Estos filtros presentaron mucha variación con respecto a los resultados, debido al tiempo de almacenamiento del agua en el recipiente del filtro debido al tiempo necesario para la recolección del agua en el hogar.

Julio Roberto Orozco Mazariegos

La gestión eficiente de sistemas de abastecimiento de agua potable requiere una micro medición precisa. En áreas rurales de Guatemala, la lectura manual de contadores presenta puntos críticos propensos a errores. Con el objetivo de mejorar este proceso, se realizó una investigación en la Aldea El Tizate, San Juan Ostuncalco, Quetzaltenango, Guatemala, para evaluar una aplicación móvil como herramienta eficiente para la lectura de contadores en áreas rurales. Se desarrolló una aplicación para dispositivos Android® utilizando Google AppSheet®, que permitió registrar los consumos y el tiempo utilizado para cada lectura en 28 usuarios de la comunidad. Se comparó con la lectura manual tradicional, cronometrando el proceso y analizando las diferencias en tiempos y resultados. Los resultados revelaron una diferencia promedio de 1.50 segundos en el tiempo de lectura entre el método manual y la aplicación móvil. Además, se observó una mayor precisión en el 82% de las lecturas utilizando la aplicación móvil. Esta investigación destaca la importancia de abordar la problemática de la lectura manual de contadores de agua potable en áreas rurales de Guatemala, enfocándose en reducir los errores. La implementación de una aplicación móvil demostró mejorar la precisión y eficiencia en el proceso de lectura. Estos hallazgos resaltan la relevancia de adoptar soluciones tecnológicas para mejorar la gestión de sistemas de abastecimiento de agua potable en comunidades rurales.

Pedro Saravia