Determination of head losses in a surge chamber: Robert Bourassa power plant case study

2007 ◽  
Vol 34 (9) ◽  
pp. 1038-1047 ◽  
Author(s):  
Musandji Fuamba ◽  
Gilles Brosseau ◽  
Éric Mainville
Keyword(s):  
Power Plant ◽  
Three Dimensional ◽  
Hydraulic Head ◽  
Transportation Systems ◽  
Flow Conditions ◽  
Flow Models ◽  
Head Losses ◽  
Water Transportation

Optimal management of power plant units is achieved when the global efficiency of the units and the minimization of the total hydraulic head losses through the water transportation systems can be combined. Evaluating these hydraulic head losses appears to be very difficult due to the complexity of the flow conditions through the hydraulic structures. A hydraulic energy based method to determine head losses in the surge chamber has been proposed in this paper, as well as a method to manage the opening of units which would optimize the production of electricity. This method was applied to a case study, and successful results have been obtained showing how the head loss varies in the surge chamber.Key words: hydraulic head losses, power plant unit, surge chamber, unit efficiency, three-dimensional flow conditions, turbulent flow models, computational fluid dynamics.

scholarly journals Risk Cloud Model for Evaluating Nautical Navigational Environments

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lijia Chen ◽  
Yanfei Tian
Keyword(s):  
Risk Evaluation ◽  
Fuzzy Theory ◽  
Cloud Model ◽  
Transportation Systems ◽  
Risk Levels ◽  
Water Transportation ◽  
Simplified Algorithm ◽  
Cloud Model Theory ◽  
Qualitative And Quantitative Characteristics

Uncertainty makes the risk evaluation of complex water transportation systems (WTSs) a difficult task. To achieve reasonable results while accounting for uncertainty, the risk evaluation of nautical navigational environments (NNEts) is often based on classical cloud model theory. This study proposes the concept of a risk cloud model (RCM) for NNEt evaluation and uses a fuzzy statistics-based computational approach to obtain the RCM parameters. As a case study, the proposed RCM method was applied to the risk evaluation of the Qiongzhou Strait. The performance of the proposed method was compared to those of a fuzzy theory-based method and an earlier proposed simplified algorithm. The results of the case study demonstrated the effectiveness of the proposed method along with several key advantages. First, the method could deal with uncertainty, take advantage of multichannel information, and evaluate risk features. Second, the RCM droplets intuitively displayed the qualitative and quantitative characteristics of risk levels, which facilitated understanding and analysis. Third, it showed a good sensitivity to ensure the refinement of evaluation results. The proposed method offered an improved approach to NNEt risk evaluation under uncertain conditions.

A Stochastic Framework to Optimize the Monitoring Strategy for the Delineation of a Groundwater Divide

2020 ◽  
Author(s):  
Jonas Allgeier ◽  
Ana Gonzalez-Nicolas ◽  
Daniel Erdal ◽  
Wolfgang Nowak ◽  
Olaf A. Cirpka
Keyword(s):  
Surface Water ◽  
Value Of Information ◽  
Hydraulic Head ◽  
Uncertainty Reduction ◽  
West Germany ◽  
Added Value ◽  
Flow Models ◽  
Digital Elevation ◽  
Stochastic Framework

<p>The boundaries of surface-water catchments can be delineated by analyzing digital elevation models using geographic information systems. Surface-water divides and groundwater divides, however, might significantly differ from each other because the groundwater surface does not necessarily follow the surface topography. Hydraulic-head measurements are needed to properly delineate a groundwater divide and thereby the subsurface boundary of a catchment, but piezometers are expensive. It is therefore vital to optimize the placement of the necessary piezometers. In this work, we introduce an optimal design analysis, which can identify the best configuration of potential piezometer placements within a given set. The method is based on the formal minimization of the expected posterior uncertainty within a sampling-based Bayesian framework. It makes use of a random ensemble of behavioral steady-state groundwater flow models. For each behavioral realization we compute virtual hydraulic-head measurements at all potential well points and delineate the groundwater divide by particle tracking. We minimize the uncertainty of the groundwater-divide location by marginalizing over the virtual measurements. We test the method mimicking a real aquifer in South-West Germany. Previous works in this aquifer indicated a groundwater divide that is shifted compared to the surface-water divide. The analysis shows that the uncertainty in the localization of the groundwater divide can be reduced with each new well. A comparison of the maximum uncertainty reduction at different numbers of wells quantifies the added value of information for each new well. In our case study, the uncertainty reduction obtained by three monitoring points is maximized when the first well is close to the topographic surface water divide, the second one in the valley, and the third one in between. </p>

Determination of the Pressure Field Using Three-Dimensional, Volumetric Velocity Measurements

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Hansheng Pan ◽  
Sheila H. Williams ◽  
Paul S. Krueger
Keyword(s):  
Poisson Equation ◽  
Temporal Resolution ◽  
Pressure Field ◽  
Three Dimensional ◽  
Vortical Flow ◽  
Flow Conditions ◽  
Velocity Measurements ◽  
Pressure Poisson Equation ◽  
Computational Fluid Dynamics Cfd

Methods to determine the pressure field of vortical flow from three-dimensional (3D) volumetric velocity measurements (e.g., from a TSI V3VTM system) are discussed. The boundary pressure was determined where necessary using the unsteady Bernoulli equation for both line integration and pressure Poisson equation methods. Error analysis using computational fluid dynamics (CFD) data was conducted to investigate the effects of spatial resolution, temporal resolution, and velocity error levels. The line integration method was more sensitive to temporal resolution, while the pressure Poisson equation method was more sensitive to boundary flow conditions. The latter was generally more suitable for V3VTM velocity measurements.

scholarly journals A practical overview of molecular replacement: Clostridioides difficile PilA1, a difficult case study

2020 ◽  
Vol 76 (3) ◽  
pp. 261-271
Author(s):  
Adam D. Crawshaw ◽  
Arnaud Baslé ◽  
Paula S. Salgado
Keyword(s):  
Structure Determination ◽  
Three Dimensional ◽  
Difficult Case ◽  
Molecular Replacement ◽  
Type Iv ◽  
Clostridioides Difficile ◽  
Α Helix ◽  
Key Aspects

Many biologists are now routinely seeking to determine the three-dimensional structures of their proteins of choice, illustrating the importance of this knowledge, but also of the simplification and streamlining of structure-determination processes. Despite the fact that most software packages offer simple pipelines, for the non-expert navigating the outputs and understanding the key aspects can be daunting. Here, the structure determination of the type IV pili (TFP) protein PilA1 from Clostridioides difficile is used to illustrate the different steps involved, the key decision criteria and important considerations when using the most common pipelines and software. Molecular-replacement pipelines within CCP4i2 are presented to illustrate the more commonly used processes. Previous knowledge of the biology and structure of TFP pilins, particularly the presence of a long, N-terminal α-helix required for pilus formation, allowed informed decisions to be made during the structure-determination strategy. The PilA1 structure was finally successfully determined using ARCIMBOLDO and the ab initio MR strategy used is described.

scholarly journals APPLICATION OF CALIBRATION CERTIFICATE OF DIGITAL LEVELING SYSTEMS IN THE MONITORING OF STRUCTURES: A CASE STUDY AT THE GOVERNADOR JOSÉ RICHA HYDROELECTRIC POWER PLANT - PR

2018 ◽  
Vol 24 (2) ◽  
pp. 235-249 ◽  
Author(s):  
Alyne Raminelli Siguel Gemin ◽  
Érica Santos Matos ◽  
Pedro Luís Faggion
Keyword(s):  
Power Plant ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Calibration System ◽  
First Order ◽  
The Past ◽  
Over Time ◽  
Equipment Performance

Abstract: The monitoring of the vertical behavior of benchmarks installed in the dam crest of the Governador José Richa hydroelectric power plant (UHGJR) has been performed by the first-order differential leveling method with the use of digital leveling systems which are composed of a digital level and a invar barcode rod. By default, the scales of these instruments are the same, but over time both can change, degrading the observations. In the past, the simultaneous calibration of these systems was not considered in the determination of UHGJR settlements, however, after the development of the first calibration system of digital leveling systems in Brazil, it was possible to investigate the equipment performance as well as to determine a scale factor to be applied to correct the level readings. The results achieved are the systems calibration used in the monitoring of the UHGJR and the calibration certificate application in leveled sections in November 2016. The maximum correction applied to the elevation differences was of the order of nine tenths of millimeters, result attributed to the region observed in the rod, since the deviations obtained in the calibration vary according to the reading position at the rod.

scholarly journals Case Study of Solar Photovoltaic Power-Plant Site Selection for Infrastructure Planning Using a BIM-GIS-Based Approach

2021 ◽  
Vol 11 (18) ◽  
pp. 8785
Author(s):  
Jae Heo ◽  
Hyounseok Moon ◽  
Soowon Chang ◽  
SangUk Han ◽  
Dong-Eun Lee
Keyword(s):  
Power Plant ◽  
Power Output ◽  
Site Selection ◽  
Solar Power ◽  
Selection Process ◽  
Three Dimensional ◽  
Economic Feasibility ◽  
Weather Patterns ◽  
Pv Panel

Evaluating the site-selection process for photovoltaic (PV) plants is essential for securing available areas for solar power plant installation in limited spaces. Although the vicinities of highway networks can be suitable for installing PV plants, in terms of economic feasibility, they have rarely been investigated because the impacts of various factors, including geographic or weather patterns, have not been analyzed. In this respect, this study conducts a case study on selecting the site for PV-panel installation in the vicinity of a highway (e.g., slopes) by integrating geographic information system (GIS) and building information model (BIM) techniques. Using location (e.g., highways, lakes, rivers), monthly solar power output, and orographic (e.g., slope) data, suitable regions are identified with the geo-spatial analysis; then, the amount of power that can be generated is evaluated in the regions. For the proposed sites, the surface conditions and potential PV systems are transformed and visualized in a BIM environment. In the results, the power output at optimal sites selected from the case area was computed at a total of 8227 MWh and was transformed into solar-panel families in three-dimensional environments. Thus, this study may help to identify optimal sites for PV plants in the unused areas near highways.

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