Prediction of rockburst based on experimental systems and artificial intelligence techniques

Rockburst is characterized by a violent explosion of a certain block causing a sudden rupture in the rock and is quite common in deep tunnels. It is critical to understand the phenomenon of rockburst, focusing on the patterns of occurrence so these events can be avoided andor managed saving costs and possibly lives. The failure mechanism of rockburst needs to be better understood. Laboratory experiments are one of the ways. A description of a system developed at the State Key Laboratory for Geomechanics and Deep Underground Engineering (SKLGDUE) of Beijing is described. Also, several cases of rockburst that occurred around the world were collected, stored in a database and analyzed. The analysis of the collected cases allowed one to build influence diagrams, listing the factors that interact and influence the occurrence of rockburst, as well as the relations between them. Data Mining (DM) techniques were also applied to the database cases in order to determine and conclude on relations between parameters that influence the occurrence of rockburst during underground construction. A risk analysis methodology was developed based on the use of Bayesian Networks and applied to the existing information of the database and some numerical applications were performed. Conclusions were established.Fundação para a Ciência e a Tecnologia (FCT

CFD analyses and performance comparison of micro-hydropowder plants

The project concerns the hydropower renewable energy technology at its micro scale: thanks to an internship performed with the Belgian startup TurbulentHydro, the purpose of this Master Thesis is to evaluate the energy performance of 2 di erent models currently under investigation: the so-called Flatblades and Streamlines con gurations. These layouts are similar in shape but di erent both in dimension and for the turbine used. After a little introduction on renewable energies and hydropower technology, the selected CFD simulation procedure and all its options have been explained as well as the choice of the turbulence model to apply, computing the meaningful parameters to add in the model. This dissertation highlights the uid dynamics behaviour by means of suitable softwares for this purpose: Autodesk Inventor, the 3D CAD mechanical design software in order to build, and edit when necessary, the geometries of the models considered, MeshMixer, a state-of-art software for locally adjusting the mesh of the starting model and OpenFOAM, a free and open source CFD program in order to run and evaluate any details of the analysis, simulating the operation conditions by means of its components and tools. Eventually, the most important CFD results are presented. Di erent con gurations bring di erent results. Regarding Flatblades model, the scope was re ned the CFD initial setup in order to achieve results as close to the real case validation as possible whereas, for Streamlines model, an additional new component has been added for improving the current design in terms of energy output at the turbine level. At the end, conclusions stated possible re nements and improvements for these simulations as well as uncertainties arose from the results that might be avoided for the next stages

2019 Projects Day Booklet

https://scholarworks.seattleu.edu/projects-day/1034/thumbnail.jp

Eccentricity movement analysis in hydropower generators : Porjus facility case study

El present treball de fi de màster té com a objectiu l'anàlisi del moviment excèntric del rotor d'un generador elèctric d'una central hidroelèctrica. Per això, es prendrà com a cas d'estudi el generador de la instal·lació Porjus que forma part del projecte Horizon 2020 AFC4Hydro. En primer lloc, es realitzarà una recerca profunda sobre l'estat de l'art dels moviments excèntrics en els rotors de màquines elèctriques en la seva particular aplicació en generadors utilitzats en centrals hidroelèctriques. Prenent com a referència aquesta recerca, es realitzarà una anàlisi de simulació utilitzant el programari Ansys Maxwell amb la finalitat de proporcionar una demostració pràctica. Aquesta tesi de fi de màster proposarà una recerca numèrica per a obtenir els resultats del moviment d'excentricitat del rotor degut a una força particular aplicada a la turbina. Aquests resultats s’obtindran a través d'una simulació electromagnètica del generador elèctric d'una turbina Kaplan de 10 MW. Per això, es realitzarà una anàlisi d'elements finits, basat en models mitjançant l'eina Ansys Maxwell, on els resultats electromagnètics mostraran com els debanaments de l'estator actuen com a filtres, atenuant els efectes d'excentricitat sobre els paràmetres elèctrics com poden ser els enllaços de flux o voltatge induït. No obstant això, aquesta tesi mostrarà que paràmetres com el parell motor, la força i la densitat de flux magnètic són útils per a identificar el moviment d'excentricitat en les màquines elèctriquesEl presente trabajo de fin de master tiene como objetivo el análisis del movimiento excéntrico del rotor de un generador eléctrico de una central hidroeléctrica. Para ello, se va a tomar como caso de estudio el generador de la instalación Porjus que forma parte del proyecto Horizonte 2020 AFC4Hydro. Por tanto, en primer lugar, se realizará una investigación profunda sobre el estado del arte de los movimientos excéntricos en los rotores de máquinas eléctricas en su particular aplicación en generadores utilizados en centrales hidroeléctricas. Tomando como referencia esta investigación, se realizará un análisis de simulación utilizando el software Ansys Maxwell con el fin de proporcionar una demostración práctica de este tema. Esta tesis de fin de master propondrá una investigación numérica para obtener los resultados del movimiento de excentricidad del rotor debido a una fuerza particular aplicada en la turbina a través de una simulación electromagnética del generador eléctrico de una turbina Kaplan de 10 MW. Para ello, se realizará un análisis de elementos finitos, basado en modelos de la herramienta Ansys Maxwell, donde los resultados electromagnéticos mostrarán cómo los devanados del estator actúan como filtros, atenuando los efectos de excentricidad sobre los parámetros eléctricos como pueden ser los enlaces de flujo o voltaje inducido. Sin embargo, esta tesis mostrará que parámetros como el par motor, la fuerza y la densidad de flujo magnético son útiles para identificar el movimiento de excentricidad en las máquinas eléctricasThis thesis targets the eccentricity movement analysis of hydropower electric generator’s rotor taking as case study the Porjus Facility generator as part of the Horizon 2020 project AFC4Hydro. In consequence, first, deep research on eccentricity movement state of the art in application to generators used in hydropower plants will be performed. Taking as a reference this research, a simulation analysis will be performed by using Ansys Maxwell software in order to provide a practical demonstration of this topic. This thesis will propose a numerical investigation in order to get the results of the rotor eccentricity movement due to a particular force applied in the turbine through an electromagnetic simulation of the electric generator of a 10 MW Kaplan turbine. A Finite Element Analysis, based on Ansys Maxwell models, will be built for this intention where the electromagnetic results will show how the stator windings filters the eccentricity effects over the electrical parameters as the induced voltage or flux linkage waveforms. Nevertheless, this thesis will conclude that parameters such as torque, force and flux density are useful to identify eccentricity movement. As well, a good understanding of how eccentricity affects in the behaviour of electric generators operation will be presente

Numerical and Experimental Investigation of Performance for Very-Low-Head Micro and Pico Kaplan Hydro-Turbines with Rim-Driven Generators

Renewable energy plays a significant role in new power generation worldwide, and hydropower is contributing to 86% of renewable electricity production within all other renewable energy resources. Simultaneously, hydropower shares 83% of U.S. renewable energy capacity and accounts for 77% of actual renewable electricity generation. However, most of the installed hydropower consists of large plants. Much potential hydro generation remains untapped, particularly at lower power and head levels. There is a substantial opportunity worldwide and across the U.S. in specific to add new hydropower generating capabilities at low-head sites such as non-powered dams, canals, and conduits with a water height of less than 30 meters, especially, where the potential of solar and wind is not available. As stated by the U.S. Department of Energy, there is an estimated potential hydropower capacity of 12,000 MW of the existed 80,000 unpowered dams with at least 3 feet of water head available. In this research, investigation of power-efficient micro and pico Kaplan hydro turbines at very-low-head with rim-driven generators to be studied and evaluated, specifically, at heads of less than 3 meters (10 ft). Optimization of performance and design for a 3D-printed conventional -with shaft- 7.6 cm (3-inch) Kaplan turbine to be carried out based on an experimental setup in the Hydro Turbines Laboratory of the University of Wisconsin-Milwaukee in addition to the utilization of Computational Fluid Dynamics (CFD). Then a shaftless rim-driven generator-based turbine (RDT) to be introduced and optimized. Such a new hydro turbine perception will increase the efficiency (of power generation) of hydro turbines in general, and the efficiency of low-head turbines in specific. The design optimization includes; the number of the blades for the turbine’s rotor (runner) and stator, the blade wrap-angle of the rotor, intake and draft tubes angles, lengths and shapes, and the guide vanes. The performance in terms of the power output and the efficiency is evaluated for the conventional turbine by utilizing CFD and by testing a 3D-printed model of the turbine in a custom-built experimental setup at different water heads (from 2.0 m to 2.6 m) and different rotational speeds (0 – 4000 rpm). The CFD setup is based on 3D transient turbulent featuring the Large Eddy Simulation (LES) model, and STAR-CCM+ is the CFD software. In addition, the high-performance computing (HPC) cluster of the University of Wisconsin-Milwaukee is used for solving the complex CFD simulations. To evaluate the advantage of the RDT over the conventional turbines, the rim-driven shaftless turbine is introduced in this research at the same boundary conditions. The RDT is not expected only to increase the efficiency of hydro turbines. It will also contribute saving the environment by allowing debris or fish to pass through the central area of the turbine, especially in the case of run-a-river hydro turbines applications. Furthermore, some applications of the RDT are presented in this study. The utilization of RDT in wastewater treatment plants (WWTPs) is one example where WWTPs usually have low or very-low head between the discharge point of the plant and the water body where the treated water is supposed to be disposed. At the same time, a significant continuous water flow rate is available all over the year for feasible hydro turbine installations. Such utilization will improve the energy efficiency of WWTPs

2018 Projects Day Booklet

https://scholarworks.seattleu.edu/projects-day/1033/thumbnail.jp

Enhancing the environmental sustainability of IT

Emerging technologies for learning report - Article exploring green I

An Ecological, Cultural, and Legal Review of Pacific Lamprey in the Columbia River Basin

Pacific lamprey (Entosphenus tridentatus) is an anadromous species in an ancient lineage of jawless fishes. The species is native to the North Pacific and its marine-accessible freshwater rivers and streams. Pacific lamprey are understudied relative to other anadromous fishes and has severely declined in abundance throughout the Columbia River Basin. Indigenous people of the Snake and Columbia River Basins have long recognized the ecological role and value of lamprey through their spiritual and cultural practices connected to Pacific lamprey. The combined effects of poor passage at dams, historic and continued habitat degradation, and altered marine host conditions have contributed to the observed decline in abundance and distribution. The unique characteristics and management history have placed Pacific lamprey in a legal and cultural grey area and provide a useful foil to Pacific salmon in considering protections for migratory fish. Here we provide a review of legal protections and recovery actions throughout the Columbia River Basin, including an analysis of the Fish and Wildlife Service’s 2004 denial of a petition to list Pacific lamprey under the Endangered Species Act. The current patchwork of measures fails to provide integrated protections across the life history of the species. This stems from a complex lifecycle spanning dozens of local, state, tribal, federal, and international jurisdictions as well as a cultural legacy of lamprey being considered trash fish by western society and early fishery managers. However, recent shifts in perceptions about the ecological value of the species and increased co-management of anadromous species within the Columbia River Basin have elevated the species as a management priority. Continued efforts to conserve and recover Pacific lamprey pose a complex and honorable challenge for fisheries managers within the Columbia River Basin