Two computational fluid dynamics (CFD) codes, Flow-3D and SSIIM 2, have been used to calculate the water flow over a trapezoidal broad-crested weir. The two programs apply different algorithms for ...making the grid and computing the free water surface. Flow-3D uses the Volume of Fluid (VOF) method with a fixed grid, while SSIIM 2 uses an algorithm based on the continuity equation and the Marker-and-Cell method, together with an adaptive grid for the water surface. The results have been compared with measurements from a physical model study, using different discharges. The deviation between the computed and measured upstream water level was between 1.0 and 3.5%. The difference between the results from the two CFD models was in the range of 1-1.5%. The accuracy of the algorithms depends on the grid size. The computational time on one core of a CPU (Intel Q9650 3.00 GHz) was between 435 and 15,500 seconds, using between 6,350 and 10,000 cells.
Sediments filling reservoirs is a common problem in the world today, with an estimated 1% of the capacity of hydropower reservoirs being lost annually through sedimentation. One of the most used ...techniques for reducing this problem is reservoir flushing. During a flood, the water level is drawn down, causing increased velocities, therefore facilitating erosion and sediment transport. During the flushing, water from the reservoir will be lost, resulting in significant economic implications for the reservoir owner. The success of reservoir flushing depends on several parameters, including water discharge, sediment properties and reservoir geometry. This study describes the use of Computational Fluid Dynamics (CFD) as a modern method to predict the reservoir flushing process. A three‐dimensional numerical model (SSIIM 2), with an adaptive, non‐orthogonal and unstructured grid has been used. Through the application of special modified algorithms (e.g., wetting/drying, free water surface), numerical modelling of sediment movement can be an alternative for planning and optimizing the flushing process for complex reservoir geometries. The numerical model was tested against data from a physical model study of the Kali Gandaki hydropower reservoir in Nepal. The total quantity of flushed out sediments, and the bed deformation in six cross‐sections, were compared, highlighting a good correspondence between the results. These include the cross‐sectional shape of a 90‐degree bend, for which secondary currents influenced the results. The study indicates that numerical models might become a useful tool for reservoir flushing predictions.
Reservoirs are a common way to store and retain water serving for a multitude of purposes like storage of drinking and irrigation water, recreation, flood protection, navigation, and hydropower ...production, and have been built since centuries. Today, few reservoirs serve only one purpose, which requires management of present demands and interests. Since each reservoir project will cause negative impacts alongside desired advantages both on a local, regional and global scale, it is even more urgent to develop a common management framework in an attempt to mitigate negative impacts, incorporate different demands and make them visible within the discourse in order to avoid conflicts from early on. The scientific publications on reservoirs are manifold, yet a comprehensive and integrative holistic tool about management of this infrastructure is not available. Therefore, a comprehensive and integrated conceptual tool was developed and proposed by the authors of this paper that can contribute to the sustainable management of existing reservoirs. The tool presented herein is based on the results from the interdisciplinary CHARM (CHAllenges of Reservoir Management) project as well as the condensed outcome of relevant literature to aid and enhance knowledge of reservoir management. The incorporated results are based on field, laboratory and empirical social research. The project CHARM focused on five different aspects related to existing reservoirs in southern Germany (Schwarzenbachtalsperre, Franconian Lake District), namely: sedimentation of reservoirs, biostabilisation of fine sediments, toxic cyanobacteria(l) (blooms), greenhouse gas emissions from reservoirs and social contestation, respectively consent. These five research foci contributed to the topics and setup of a conceptual tool, put together by the research consortium via delphi questioning, which can be found alongside this publication to provide insights for experts and laymen. Conceptualising and analysing the management in combination with quantitative and qualitative data in one descriptive tool presents a novelty for the case studies and area of research. The distribution within the scientific community and interested public will possibly make a positive contribution to the goal of sustainable water resources management in the future.
(+ Intelligence ?) Wisdom Hoppe, Anett; Haun, Stefan; Inthorn, Julia ...
Advances in Computational Intelligence
Book Chapter
Recenzirano
The concept of wisdom has been a term of reflection since the first philosophical definition attempts by Aristotle (384 BC – 322 BC). Different religions and sciences offered possible properties and ...facets of wisdom – without ever coming to an agreement on how to define the term. As especially cognitive sciences provided new insights during the last decades the time might have come for a revised, more conclusive definition or at least modelization of wisdom, using and integrating the insights of different disciplines out of humanities, cognitive and natural science to create a common base for further interdisciplinary research. Furthermore, we discuss possible measures that are able to cover a least fundamental properties of wisdom including its vague aspects.
The characteristics of decisions and the evaluation of their outcome are highly complex. In this paper, we first give a short analysis of different types of decisions such as long-term and short-term ...decisions or dilemmas by discussing different scenarios and examples. We identify characteristics of decisions and give a short account of the usually quite complex decision scenarios involved and the high uncertainty of long-term predictions. We introduce serious games as a tool for evaluation of decisions through simulation. By using serious games long-term effects of decisions can be evaluated and known measurement criteria for short-term decision can be transformed to support long-term decisions.
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