The data on the hydrodynamic loads on the water body in the presence of cavitating energy without erosive dampers on it are presented. It is shown that these loads increase in comparison with the non-cavitation mode, but, despite this, the use without cavitation dampers in appropriate conditions is advisable, providing favorable downstream regimes and reducing the volume of construction work and the cost of construction. It is proved that for multiple types without erosive energy absorbers, data were obtained on the averaged and pulsating vertical and horizontal loads on the absorbers and the slaughter plate, which allows us to carry out the required calculations of the strength and stability of the elements of the downstream devices. As a result of cavitation and cavitation studies of erosion-free energy absorbers in cavitation stands, coefficients of any resistance C x of several types of aerosol-free absorbers were obtained; as well as pulsation standards measured by “point” sensors for the vertical hydrodynamic effects of the flow on the water culvert in the installation zone of an erosion-free damper.
В результате многолетней научнопрактической работы в племенном стаде выведены новые семейства швицкой породы. Коровы этих семейств в 3 поколениях характеризуются высоким удоем молока, жирномолочностью, выраженным молочным типом, долголетием и другими ценными селекционными признаками. Удой у дочерей родоначальниц составил 42717896 кг молока жирностью 3,954,26, внучек 49358537 кг и 4,04,30, правнучек 35095528 кг и 3,974,25. Коровы новых семейств проявили хорошую воспроизводительную способность и даже за 12 лактацию давали по теленку в год. Разведение скота с учетом семейств способствует повышению темпов качественного совершенствования швицкой породы.As a result of many years of scientific and practical work in the breeding experimental herd, new families bred of the Shvits breeds have been brought out. Cows of new families in three generations are characterized by high milk yield, fatty milk, pronounced milk type, longevity and other valuable breeding characteristics. Milk by the daughters of the ancestor was 42717896 kg of milk with fat content of 3.954.26, granddaughters 49358537 kg and 4.04.30, greatgranddaughters 35095528 kg and 3.974.25 Cows of new families showed good reproductive ability and even for 12 lactation was given per calf per year. Livestock breeding, taking into account the families, contributes to an improvement of the rate of qualitative improvement of the breed.
The article gives the reason for the formation of Lake Aydarkul, according to which Lake Aydarkul began to form, starting from the catastrophically high year of 1969 - as a result of the discharge of 21 cubic kilometers of Syrdarya waters from the Shardara reservoir. The area of the lake system reached 2000 km2, salinity of water – 2 – 4 g/l. In the next decade, there was a drop in the water level in the lakes and deterioration in its quality. By 1978, the depth decreased from 25 to 20 meters, and salinity increased to 7-8 g/l. An analysis of the available materials devoted to this problem showed that the water surface of Aydar and Tuzkan lakes extends from west to east for more than 180 kilometers, and the adjacent chain of Arnasay lakes stretches from north to south for more than 70 kilometers. The reason for the salinity of Aydarkul was indicated - before the commissioning of the Shardara reservoir, salt lakes were located on the site of the lakes, and only in the Tuzkan Basin fed by the Kly River was a shallow salt lake. The problem can be solved by transporting an additional volume of water to the lower reaches of the Amudarya, which will improve the ecological situation in the Aral Sea region, provide, over time, the formation of fresh lakes and create a water management system Syrdarya - Aydarkul - Zarafshan - dead lakes - Amudarya. This system can serve the broad development of fisheries, and also contribute to the opening of new agricultural areas of the republic, while creating several hundred new jobs. A method is recommended for solving an important national economic task of the industry. It is proposed that for the formation of the water system Syrdarya – Aydarkul - Zarafshan - “dead lakes” – Amudarya – Priaralye, it is necessary to design and build the main canal with several sections of a length of about 250 km, each of which communicates with the lake of the above system, will provide gravity communication of three large rivers of the Aral Sea basin. It is proposed to design the main canal with improved lining, which will provide high efficiency, which, in turn, will reduce the filtration coefficient and contribute to an increase in water intake for the needs of the national economy, expansion of irrigated areas and the development of fisheries in the region, and improvement of the ecological situation in the Aral Sea region.
The article is devoted to solving the problems of reducing the useful volume of bulk reservoirs, which is an urgent task of water management. The development of the design allows to reduce the volume of incoming sediment into the reservoir thicket is the main goal of the present work. The analysis of materials of field studies and a review of existing scientific works was the basis of the research method. The results of field studies on the study of channel processes in the downstream of the feeder channel of a low-pressure reservoir and the dynamics of their siltation. It has been established that the reservoirs accumulate only 0.3-10% of the annual river flow and the degree of annual silting of the capacity of such reservoirs is on average 0.5-2.0%. After 25-50 years, reservoirs may lose half of their usable capacity and after 40-80 years, a complete failure of operation is possible. To slow down this process in the basins of the self-leveling reservoirs, a new structure of structures developed, which ensures an even flow of water in the supply channel and maximum sedimentation of sediments in the channel, which prevents them from entering the reservoir bowl.
As the experience of operating high-pressure spillway structures shows, the operating conditions of the downstream extinguishing devices are very difficult. At flow rates, more than 12–15 m/s, downstream damping devices, as a rule, operate in a cavitation mode. First of all, this mode of operation gives rise to erosional destruction of the damper itself and the waters near it. This occurs where the cavitation torch closes on the structure. Attempts to avoid these desirable phenomena by lining erosion sites with steel sheets do not always lead to the desired result since it is not uncommon for the steel lining to be torn off by hydrodynamic forces. The separation of the cladding occurs in two cases: firstly, when the cladding is not in close contact with the concrete to be protected, and secondly, its anchoring is not enough. In both cases, fracture occurs from fatigue phenomena in the metal due to multiple oscillatory cycles from hydrodynamic loads. It is difficult to avoid this in cavitation modes since the spectrum of pressure pulsations, in this case, is very wide, which leads to oscillations of linings at resonant frequencies. Apparently, the strength of the linings is an object of special research, and in the future, it should be dealt with theoretically and experimentally. Hydrodynamic forces at high flow rates in the zone of intense energy extinguishing can reach such values that they can lift and overturn concrete slabs of water walls and water walls. Currently, there are practically no specific and accounting for vertical hydrodynamic loads on slabs of water walls in the presence of cavitation on erosion-free absorbers in the technical literature. To a certain degree of approximation, it is possible to use experimental data obtained on a model of the same structure but operating without cavitation, as data on hydrodynamic loads in the downstream of structures operating in a cavitation mode. The main disadvantage of such comparisons is that there is no guarantee that the amplitude and frequency characteristics of the flow during cavitation do not change (in particular, the amplitudes do not increase) as the cavitation limit is approached.
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