Hasil untuk "Technical hydraulics"

María Victoria Mitre Núñez, Luis Roberto Alfaro De Arcia, Denisse Morales De León

Conocer el estado de los cuerpos de agua, tanto superficiales como subterráneos, es fundamental para la gestión adecuada de las cuencas prioritarias del país, como la del río Guararé, en Panamá. El objetivo de este proyecto fue establecer la relación entre las porquerizas, los puntos de contaminación y su posible impacto en la calidad del agua. Para ello, se realizaron muestreos en puntos específicos de la cuenca y se utilizaron herramientas de Sistemas de Información Geográfica (SIG). La investigación buscó identificar fuentes de contaminación y comprender cómo afectan al ecosistema acuático de la región. Se llevaron a cabo dos campañas de muestreo, con análisis de calidad de agua realizados en sitio y en laboratorio. Estos estudios permitieron obtener datos sobre los parámetros críticos de calidad hídrica. Posteriormente, se elaboraron mapas de contaminación con el objetivo de identificar y visualizar sitios críticos y potencialmente críticos en la subcuenca. Los resultados muestran que, aunque existe cierta correlación entre la densidad de porquerizas y algunos parámetros de calidad de agua muestreados, la contaminación hídrica parece estar más asociada a la concentración poblacional y otras actividades humanas. Estos hallazgos sirven de base para establecer estrategias de intervención, promover la gestión integrada del recurso hídrico en la región y reducir los impactos negativos sobre los cuerpos de agua.

Guillaume L. Giudicelli, Guillaume L. Giudicelli, Fande Kong et al.

High fidelity simulations of nuclear systems generally require a multi-dimensional representation of the system. Advanced nuclear reactor cores are governed by multiple physical phenomena which should be all be resolved, and the coupling of these physics would also need to be resolved spatially in a high-fidelity approach, while lower fidelity may leverage integrated quantities for the coupling instead. Performing a spatially resolved multiphysics simulation can be done on a single mesh with a single coupled numerical system, but this requires catering to each equations’ time and spatial discretization needs. Instead, each physics, usually neutronics, thermal hydraulics and fuel performance, are solved individually with the discretization they require, and the equations are coupled by transferring fields between each solver. In our experience coupling applications within the MOOSE framework, mostly for advanced nuclear reactor analysis, there are several challenges to this approach, from non-conservation problems with dissimilar meshes, to losses in order of spatial accuracy. This paper presents the field transfer capabilities implemented in MOOSE, and numerous technical details such as mapping heuristics, conservation techniques and parallel algorithms. Examples are drawn from nuclear systems analysis cases to illustrate the techniques.

Abdulkadir Ozturk, Muhammed Enes Atik, Mehmet Melih Koşucu et al.

Floods are among the most destructive natural disasters and can devastate human life, infrastructure, and mobility in urban areas. It is necessary to develop a simulation model suitable for disaster management to prepare for flooding and facilitate rapid response interventions. The advantage of a three-dimensional (3D) geographic information system (GIS) is that it allows researchers to perform more successful spatial analyses than traditional two-dimensional (2D) systems. In this study, real-time 3D flood simulations were created for the Bozkurt district of Kastamonu, Türkiye, integrating GIS and game engine technologies. Land use land cover (LU/LC) map, digital elevation model (DEM), soil properties and climate data of the study region constitute the input data for the hydrological model. DEM and building footprints are also used to create 3D models of the buildings in the region. Through the Soil and Water Assessment Tool (SWAT) analysis, a hydrological model that included environmental factors such as precipitation, runoff, and soil erosion was created. The average flow rate for the same period, obtained from flow monitoring stations in the Bozkurt district, was 4.64 m³/s, while the flow rate obtained with the SWAT+ model was 4.12 m³/s. Using the flow parameters obtained with SWAT, 3D flood models were developed on Unreal Engine (UE). The flood simulation created with UE and the flood disaster experienced in 2021 in the region were compared on an area basis. The obtained simulation accuracy was 88%.

C. Haring, Leanne M. Stepchinski, Garrett T. Menichino

This technical note (TN) presents a rapid, nationally applicable web application for analyzing channel hydraulics and floodplain connectivity. The tool uses locally derived relative elevation models (REMs) that allow users to quantify hydraulics, like velocity and shear stress, and floodplain connectivity metrics, like inundation extent and storage volume (Haring and Dougherty, forthcoming).* By delineating cross sections directly from publicly available high-resolution terrain, the tool provides a rapid hydraulic assessment without requiring field survey data and also helps prioritize reaches for more detailed assessments.

S. Vol'vak, Yuriy Ul'yancev, Dmitriy Baharev et al.

The textbook was created according to the program of the discipline "Fundamentals of hydraulics and heat engineering". It contains brief theoretical information on the academic discipline, material on the study of methods for determining the physical properties of liquids and the thermophysical properties of the working fluid, devices for conducting hydraulic and thermal experiments, devices and principles of operation of hydraulic and thermal machines. The given material will allow you to develop the skills of applying theoretical knowledge in solving specific practical problems. It is intended for studying the discipline, conducting practical exercises and independent work. Meets the requirements of the federal state educational standards of secondary vocational education of the latest generation. For students studying in the specialty 02/35/16 "Operation and repair of agricultural machinery and equipment" and other technical specialties of secondary vocational education and higher education training areas, as well as for teachers and engineering staff of the agro-industrial complex.

Mariia Sergeeevna Zavialova

The object of the study is the scientific and technical activity of the hydraulic laboratory of the St. Petersburg Polytechnic Institute. The subject of the study is the organization and implementation of scientific and technical activities of the hydraulic laboratory. The purpose of the work is to study the hydraulic laboratory as a particularly significant scientific center in St. Petersburg at the beginning of the XX century. The paper indicates the technical equipment of the laboratory, the contribution of the scientists-organizers of the Polytechnic Institute to the formation of national hydraulic science. In 1905, a hydraulic laboratory was opened at the electromechanical department. Its opening was associated with the need to teach students of the technical departments of the Institute hydraulics. In addition to educational activities, applied research in the field of hydraulics was carried out in the laboratory. The scientific and technical activities of the hydraulic laboratory have opened up new opportunities for applied research in the field of hydraulics and hydraulic engineering. I. G. Esman, B. A. Bakhmetev, and N. N. Pavlovsky carried out their research activities in the laboratory. Comparative and descriptive methods were used when writing a scientific article. The principles of historicism and objectivity made it possible to conduct a comprehensive analysis of organizational features and technical characteristics in the creation and operation of a hydraulic laboratory. Among the studies conducted in the hydraulic laboratory were I. G. Esman's studies on the movement of liquids of increased viscosity through local resistances, B. A. Bakhmetev built a tray with a variable bottom slope, which allowed him to study the shapes of the free flow surface. The material and technical equipment of the laboratory, the presence of an impressive instrument range, updating and replenishment of the material base, as well as organizational work on the part of the staff of the Polytechnic Institute led to the fact that the hydraulic laboratory was the leading scientific and technical center in the country. In the hydraulic laboratory, a draft regulating device was created on the discharge channel, a draft water pipeline for supplying warm water to the receiving structure of the pumping station, in the 1920s. In the hydraulic laboratory, the spillway profile of the Yaroslavl hydroelectric dam was tested.

Ali Mahdavi

Yandong Gao, Maolin Zhou, Weilin Xu et al.

The vibration mode of the radiation surface of transducer (or structure of supersaturated cavitation cloud in thin liquid) is investigated experimentally by high-speed photography. The classification of saturated, supersaturated and undersaturated cavitation clouds was proposed, and a comparison was made between saturated and supersaturated cavitation cloud structures in liquid thin layers. The characteristics and formation mechanism of supersaturated cavitation cloud structure were investigated. Based on the close correspondence and rapid response between the distribution of supersaturated cavitation clouds and vibration modes of radiation surface, a new approach is proposed to measure the vibration mode of transducer operating at high power and large amplitude in real time.

Mébirika Benyamine, Naïma Fezzioui, Zahira Tehirichi et al.

This study presents a numerical investigation of turbulent crude oil flows in circular curved pipelines, with a focus on the deposition patterns of solid particles within the fluid. Simulations were conducted using the Reynolds–Averaged Navier–Stokes equations coupled with the k–ε turbulence model to examine the influence of structural characteristics, such as bend curvature angle and bend curvature radius, on flow dynamics and particle deposition. The results reveal that the complex flow patterns generated by these geometric features significantly affect pressure gradients and particle trajectories. Specifically, the study shows that turbulent flows within bends exhibit intricate behaviors, with deposition patterns being strongly influenced by the pipeline’s geometric parameters. Sand particles, commonly present in petroleum flows, are found to be more effectively transported in pipes with larger curvature angles, while they exhibit a higher propensity to settle at smaller curvature angles and larger bend curvature radii. Furthermore, the simulations indicate that the majority of deposited particles accumulate on the inner wall immediately downstream of the elbow entrance.

S. Vol'vak, Yuriy Ul'yancev, Dmitriy Baharev et al.

The textbook contains material on the study of the basics of hydrostatics and hydrodynamics, technical thermodynamics, the theory of heat transfer and heat transfer, heating, air conditioning and ventilation of premises, the device and principle of operation of hydraulic machines, heat engines, heat exchangers and thermal power plants. It is intended for students in the specialty 02/35/16 "Operation and repair of agricultural machinery and equipment" and other technical areas of training and specialties of higher and secondary vocational education, as well as teachers and engineering and technical workers of the agro-industrial complex.

M. Moreno, José del Carmen Jiménez-Hernández, Josefin Barajas et al.

. The main objective of hydraulics applied in oil well drilling is to ensure cleanliness at the bottom of the well, this consists of keeping in continuous movement the solids or cuttings of the formation, transporting the largest amount of them from the bottom and the annular space to the surface, thus minimizing the existence of unwanted events such as sticking, entrapment, among others. Each oil well has specific geological, geophysical and geomechanical characteristics that must be taken into account for its design, based on technical and scientific considerations that allow the establishment of its mechanical state and its exploitation engineering studies. The rheological behavior of a fluid in these wells cannot be generalized, even if they are separated by a few hundred meters. This paper describes the development of a graphical computational model for the fast and efficient calculation of the various hydraulic aspects associated with onshore oil well drilling. The model is arranged in three stages: First, the position of the drill pipes in the drillstring is evaluated and their pull margin is determined. Then, the hydraulic calculation procedures of national and international companies are developed. Finally, rheological models (Bingham plastic and exponential law) are used for fluid behavior. The model was developed with Microsoft Visual Basic.

Jeremy L. Schoen

It was nice to see a step back from the inflated validities (e.g., Sackett, Zhang, Berry, & Lievens, 2022) promoted by many meta-analysts. Still, the use of corrected validities for purposes of selection is a dubious practice. Although the mistake of correcting for range restriction of unrestricted samples is now apparent, other problems—both technical and legal—still abound. I briefly review works (most of which are more than 40 years old) that describe these challenges. I then provide suggestions for practitioners and researchers. Ultimately, the quote from Robert Fulghum seems appropriate: “Anything not worth doing is worth not doing well.”

Eduardo Ariel Ruiz Murillo

La protección de los recursos hídricos a través de la implementación de procesos de tratamiento de las aguas residuales que son depositadas en estos se ha convertido en un gran reto para la región centroamericana, dado que cada vez es más notoria la eutrofización de los cuerpos de agua derivado de las descargas de agua residual con significativas concentraciones de nitrógeno y fósforo. Derivado de lo anterior, se ha estado realizando diversas investigaciones para proponer mecanismos locales que permitan reducir estos nutrientes, siendo uno de ellos la utilización de la semilla de Tamarindus índica debido a que su composición química se ha encontrado ácido glutámico lo cual según Campos y colaboradores (2003) son responsables de su capacidad de coagulación. En este estudio se analizó el desarrollo de un coagulante a base de la semilla de Tamarindus índica para evaluar su capacidad de reducción de fosfato-P y nitrato-N en aguas residuales proveniente del tratamiento secundario, obteniéndose una reducción máxima de 46.42±24.06% para el fosfato-P y de 37.87±29.61% para el nitrato-N, aplicando dosis de 120 y 95 miligramos de coagulante orgánico respectivamente. Por lo anterior la semilla de Tamarindus índica puede ser una opción para reducir el fosfato y nitrato cuando se requieran reducciones menores a 50%.

Dauletmuratova Nadejda, Abdiganieva Gulshad, Tolepova Sharigul et al.

This article is devoted to the problems of water supply to the population, which are associated with the current water management situation, such as the shortage of water resources, the decline in the quality of surface and groundwater, the technical condition of pipelines. In this situation, there is a need to eliminate or mitigate the current situation, so the study of hydraulic friction losses in water conduits is of national economic and scientific importance.The article deals with the issues of determining the pressure loss in water pipes under various modes, the causes of clogging of pipelines in water supply systems and the basic formulas of engineering hydraulics under conditions of insufficient water supply to the population. Solving the problem will increase the reliability of pipeline operation, meet the requirements of the population, and meet the minimum of the reduced costs for construction and operation.

Pengfei Zhang, Kai Song, Chaoxu Chen et al.

Aerators with sharp lateral enlargements and bottom drops generally cause adverse effects in spillway tunnels with a mild base slope, including serious cavity back flow and water wings striking the tunnel roof. Taking RM Hydropower Station’s spillway tunnel as its example, this paper proposes a new type of combined aerator characterized by a “variable base slope” longitudinally and a transverse “sharp enlargement plus straight section.” This not only increases cavity stability, resulting in more effective aeration, but also inhibits the development of water wings, contributing to an improved pattern of water flow. In addition, this paper systematically explores the influence of the flip bucket (drop), gently sloping section, and steeply sloping section of the “variable base slope” aerator upon the aerated cavity and summarizes the rules according to which the sharp lateral enlargement and diffusion angle influence the formation of water wings. This offers technical solutions, with theoretical support, for the design of aerators in spillway tunnels with a mild base slope.

M. Wilke

Geosynthetics are well known for substituting mineral filter layers for revetments. Apart from this established and common application they offer more specific and technical solutions for coastal and inland water structures. Typical hydraulic constructions like breakwaters and dikes can be strengthened and optimised using geotextiles or geosystems (bags, tubes, etc.). Till today the potential of geosynthetics for civil works in the marine environment is underestimated. Furthermore, the awareness by designers, construction companies and project owners for geotextile alternatives, saving time, money and enhancing the carbon footprint, can be substantially increased. Main reasons for the ignorance are missing design guidelines and a not existing general overview of their applicability in coastal zones and inland waters. This paper is intended as a first step towards a holistic approach to geosynthetics in hydraulics.

M. Gómez, J. Téllez-Álvarez, B. Russo

Urban pluvial floods can be produced or exacerbated by insufficient inlets density or by their poor hydraulic efficiency. A proper regard on inlet hydraulic performance is essential to guarantee the correct functioning of urban drainage systems during heavy storm events. The recent advances in computation analysis in the field of hydrodynamics modelling allow to use the well-known concept of dual drainage for design and planning purposes simulating flow transfers between surface layer (street) and underground layer (sewer) through a proper hydraulic characterization of inlet efficiency. Currently, powerful commercial software packages allow the simulation of flow transferring including different approaches and formulas. Many of these approaches include the possibility to treat sewer inlets as an orifice. In this context, this paper presents a methodology to obtain orifice discharge coefficients for three inlets previously tested at the Hydraulic Laboratory of the Technical University of Catalonia. Obtained results show discharge coefficient values between 0,18 and 0,58 with a Froude number between 1.12 and 4.4, quite far from usual recommended values. The procedure can be applied even to non-tested grates.

Shenglong Gu, W. Zheng, H. Wu et al.

This technical note presents the DualSPHysics application to spillway hydraulics, and an extensive comparison has been made between the single-water and two-phase water–air modelling approaches. It has been found that the DualSPHysics code based on the smoothed particle hydrodynamics method could provide a promising design tool for spillway flows in the engineering field. The model is first validated on a documented skimming flow and the numerical results are also compared with those computed from a smoothed spillway flow. Then the model is further validated by a laboratory experiment for a nappe flow, where the computed flow depth and velocity are validated against the physical measurements. It has been disclosed that for a skimming flow, the single- and two-phase SPH modelling approaches lead to small differences, while for a nappe flow with more serious free surface motion, the two-phase model clearly improved the simulation accuracy. After the model is fully validated, it is applied to investigate a practical spillway flow under different flow discharges, bed slopes and step numbers, covering two distinct spillway flow regimes. From the simulation results, the flow energy dissipation features are investigated with regards to the different flow rates and spillway configurations. It has been found that the energy dissipation efficiency of a spillway is proportional to the number of the steps but inversely proportional to the flow discharge and the spillway slope.

Yujie Wang, C. Frankenberg

Abstract. Plant hydraulics gains increasing interest in plant ecophysiology and vegetation modeling. However, the hydraulic properties and profiles are often improperly represented, thus leading to biased results and simulations, e.g., the neglection of gravitational pressure drop results in overestimated water flux. We highlight the commonly seen ambiguities and/or misunderstandings in plant hydraulics, including (1) the distinction between water potential and pressure, (2) differences among hydraulic conductance and conductivity, (3) xylem vulnerability curve formulations, (4) model complexity, (5) stomatal-model representations, (6) bias from analytic estimations, (7) whole-plant vulnerability, and (8) neglected temperature dependencies. We recommend careful thinking before using or modifying existing definitions, methods, and models.

Daniel Caviedes‐Voullième, M. Morales-Hernández, M. Norman et al.