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  • Author: Ievgenii Gerasimov x
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Abstract

One of the ways to ensure a reliable operation of irrigation systems is to protect them from water hammer (hydraulic shock) damage that occurs when starting or stopping a pumping station. This can be achieved by creating conditions in which a water hammer will not occur in the pressure pipeline as a result of closing the end gate valve (EGV). The aim of the present study was to investigate processes occurring in the pipeline during a linear closure of the EGV, during a closure with one break point and during an intermittent closure, as well as to verify the effectiveness of a combined end gate valve closure of the pipeline. Based on experimental data and calculations, the article recommends a linear closure of the EGV with one break point.

Abstract

The environmental assessment of the surface water quality of the Western Bug River has been made using the system of classification quality of land surface water of Ukraine in accordance with the approved methodology, which allows comparing water quality of separate areas of water objects of different regions. The calculation of the environmental assessment of water quality has been carried according to three blocks: block of salt composition, block of trophic and saprobic (ecological and sanitary) indicators and block of indicators of content of specific toxic substances. The results are presented in the form of a combined environmental assessment, based on the final conclusions of the three blocks and consists in calculating the integral ecological index. Comprehensive studies of changes in the water quality of the Western Bug River have been conducted within the territory of Ukraine for a long-term period. The water quality of the river on the final values of the integral indicators of the ecological condition corresponded mainly to 4nd category of the 3rd class – the water is “satisfactory” by condition and “little polluted” by degree of purity (except for points of observation that located within the Volyn region, where the water quality corresponded to 3rd category and the 2nd class. It is “good” by condition and “fairly clean” by the degree of purity). Visualization and part of the analysis are performed using GIS technologies in the software of the ArcGIS 10.3.

Abstract

In the article we developed the design principles and implementation of a complex model and optimized the design parameters of drainage. The study was based on the implementation of interconnected structural and technological forecasting simulation and optimization model blocks, which in turn allowed to justify the optimal design parameters and drainage considering multiple natural and agronomic conditions and reclamation facilities. Example of evaluating the performance of drainage on drained lands was made for the conditions of a real project, implemented on lands of agricultural holding “May Day” located within of drainage system “Ikva” in the Rivne region. For the object conditions (average decade formation conditions of the drainage flow module for growing perennial grasses, winter cereals and potatoes) the estimated duration of the growing season was 214 days (100%), of which the total duration of drainage was 60% and included different levels of efficiency: 39% – ecological, 15.5% – technological and 5.5% – economic. The duration of its critical operations (forming module drainage flow exceeds the design of its value) does not exceed 5%. Thus, this approach enables the assessment of drainage with predetermined or specified parameters in the construction or renovation of drainage systems on different levels of effectiveness. It can be effectively used in the overall complex predictive and optimization calculations to substantiate the design and parameters of agricultural drainage, taking into account the variability of natural agrotechnical and reclamation conditions of a real object.

Abstract

The situation when groundwater considerably rises above the “normal” level, water intake, lowering of groundwater levels and other relevant practical tasks require the drainage facilities. The most effective techniques of numerical studies of the corresponding boundary problems at present time are methods of dealing with inverse boundary value problems (conformal and quasi-conformal mappings). As basis of this research we used the case of combining the fictitious domain methods with quasi-conformal mappings of the solution of nonlinear boundary value problems for the calculation of filtration regimes in environments with free boundary areas (depression curves) and zones of “mountainous” areas.

This paper reviews the stationary issue of flat-vertical stationary non-pressure liquid filtration to horizontal symmetric drainage. In the paper a practical methodology for solving boundary value problems on conformal mappings is suggested for the calculation of the filtration process in the horizontal symmetrical drainage.

The idea of block iterative methods was used during the creation of the corresponding algorithm which is based on the alternating “freeze” of the anticipated conformance parameter, the internal and boundary connections of the curvilinear area.

The results of the conducted numerical calculations confirmed the effectiveness of the suggested problem formulations and algorithms of their numerical solution and the possibility of their use in the modelling of nonlinear filtration processes occurring in horizontal drainage systems, as well as in the design of drainage facilities and optimizing other hydrosystems. Therefore these results are of great importance.