scholarly journals Hydraulic studies of the throughput of the water intake structure of the Tuyamuyun hydroelectric complex

2021 ◽  
Vol 264 ◽  
pp. 03059
Author(s):  
Ulmas Khusankhodjaev ◽  
Odil Kadyrov

The article presents the results of experimental studies to determine the throughput of the right-bank water intake structure and bottom galleries, the hydraulic regime in the galleries, and the movement of bottom sediments in them. Based on the results of the studies, a series of curves were obtained for the dependence of the discharge on the water horizon in the upper pool and the value of the opening of the gate of the intake structure. Checking the work of the galleries together with the working water intake holes showed that there is no mutual influence of them on each other. The total consumption of water passed through the water intake and galleries is practically equal to the sum of the consumption of water passed through these structures separately. It was found that the main amount of sediment accumulated in the headwater will fall into the left gallery, while slightly less (about one third) will fall into the right span, and only a small remainder leaves through the weir, while the water flow rate was distributed as follows: Qgal = 1.65Qwater.

2014 ◽  
Author(s):  
Khashayar Teimoori ◽  
Ali M. Sadegh

Packing in cooling towers is commonly used in nuclear power plants and air conditioning systems. However their efficiency with respect to the inlet air flow rate and the temperature of the water has not been fully investigated. In this research, the efficiency of packing rotational speed with respect to the wet counter flow of a cooling tower is experimentally investigated. In our experimental studies, six elliptical wooden plates that are equally spaced are used as a packing tower. The packing area of 0.85 m2 is considered with the following rotor speed ranges: 0.5, 3.5, 10, 15 and 17 rpm. It is assumed that the water mass flow rate is proportional to the inlet air to the tower. Six mass flow rates starting from 0.2 to 2.8 kg/h and the inlet air and water temperatures of 27°C and 45°C, respectively, are considered. The results illustrate that for the range of 0 to 5 rpm of the packing rotational speed the cooling rate of water is increased 3% for the water flow rate of 2.8 kg/h, and 24% for the water flow rate of 0.4 kg/h. Additionally, as a result of the increased rotational speed from 5 to over 17 rpm the cooling rate at both maximum and minimum water mass flow rates are increased from 13.9 to 34.4 percent, respectively. Furthermore, the water outlet temperature is reduced from 8.6°C to 3.3°C in the least and the most mass flow rates leading to the increased speed from 5 to 17 rpm, respectively. The experimental relationship between the inlet air temperature and the rotational speed of the packing has been determined. Also, the inlet water temperature at the maximum flow rate has been decreased to 3.4 and at the least water mass flow rate it has been decreased to 29 percent for the range of rotational speed from 5 to over 17 rpm of the packing rotation. All the results are depicted in several curves to show the actual variations of the variables.


Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 269 ◽  
Author(s):  
Manish Kumar ◽  
Praveen Mishra ◽  
Apurba Kumar Roy

The continuous casting process (CCP) is the most vital part of steelmaking. The flow pattern near the submerged entry nozzle (SEN) and mould greatly influence the quality of the slab produced. The present investigation was carried out to gain knowledge regarding the meniscus fluctuation under different nozzle port blockage conditions by water model experiments. The experiments were carried out to study the effect of no blockage, 25% blockage, 50% blockage, and 75% blockage of the nozzle port on mould-level fluctuations. The result shows that when the liquid flow rate increases, the wave amplitude increases. In these experiments, the average and maximum meniscus fluctuations were measured while changing different variables such as the water flow rate, gas flow rate, and one-side percentage blockage of the SEN port while the other side was fully open. The observation shows that when the port size decreases, the fluid steel mixed from the obstructing side to the open side results in asymmetry. The average and maximum wave amplitude increases with decreasing submergence depth. It was observed that the maximum height of the standing waves in the mould continued rising on the non-blocked side of the SEN. Blockage increases from 25% to 75%, and with 75% blockage of the right side of the SEN port, the mould-level fluctuation at the left side of the mould was extreme, while that of the right side was relatively quiet.


Author(s):  
Corey J. Fisher ◽  
Karen C. Scott ◽  
Hayley K. Reiter ◽  
Melissa A. Reid ◽  
Charles M. Roe ◽  
...  

Abstract OBJECTIVE To evaluate the effects of a flotation vest (FV) and water flow rate (WFR) on limb kinematics of dogs swimming against a current. ANIMALS 7 (1 male and 6 female) healthy adult Siberian Huskies. PROCEDURES Dogs were habituated to swim with and without an FV beside an investigator in a continuous-flow pool against WFRs up to 2.9 km/h. During each of 4 experimental sessions in a repeated-measures study, markers were wrapped around the right carpus and tarsus, and a video was recorded while each dog swam with or without an FV for about 2 minutes at each of 7 WFRs between 0 and 2.9 km/h when the WFR was incrementally decreased or increased. Motion tracking software was used to measure stroke excursion and frequency. RESULTS Stroke excursion varied more than frequency among all dogs and in response to changes in experimental conditions. The male dog and 1 female dog were unable to complete the study. For the remaining 5 dogs across all experimental conditions, mean tarsus excursion was 30% that of the carpus. Mean total excursion (sum of the excursion-frequency products for the carpus and tarsus) decreased when an FV was worn and increased with WFR by 69% and 19% when WFR was incrementally increased and decreased, respectively. CONCLUSIONS AND CLINICAL RELEVANCE In dogs, range of motion during swimming was greater for the carpus than tarsus, when an FV was not worn, and increased more with WFR when WFR was incrementally increased. Those factors should be considered during swimming-based rehabilitation.


2016 ◽  
Vol 6 (2) ◽  
pp. 135-139
Author(s):  
Muradulla M. MUKHAMMADIEV ◽  
Shavkat I. KLYCHEV ◽  
Kurbon S. DZURAEV ◽  
Farkhodzhon E. MADALIEV ◽  
Sulton BEKMURODOV ◽  
...  

The results of the calculated and experimental studies of water velocity distribution in the central vertical crosssection of flow in the plane of the shutter are introduced. Shutter model allowing to investigate the water rate for conventional planar gate and the gate to the guide flap is presented. It is shown that the relative coordinate section characterizing the average water flow rate is not independent on the height of the water level and the shutter opens, but only on their ratio. Experimental graphical dependence of the average velocity of the water in the central vertical section shutter and coordinates of its position are introduced. Experiments showed that the water flow in the gates has a vertical speed component.. The obtained results enable us to develop methods for measuring the water flow in the gate.


2019 ◽  
Vol 12 (3) ◽  
pp. 200-205
Author(s):  
V. E. Mikhailov ◽  
S. P. Kolpakov ◽  
L. A. Khomenok

Topical issues of creating test benches for power drive units are considered. The results of testing a hydraulic dynamometer with the aim of clarifying its characteristics are presented. When creating test benches, it is important to choose the right power damping system with its accurate measurement. For these purposes hydraulic dynamometers (HD) are used. The domestic industry has not yet mass-produced them, experimental development is underway. In this regard, it seems appropriate to use imported diesel engines, for example, Japanese-made, of type CFT-9.0 manufactured by Fuchino Co Ltd. This equipment has a commercial preference over other foreign manufacturers. This article discusses the principle of HD operation, its design features, the identified shortcomings and ways to address them, the results of tests of the gas engine on a special bench of JSC «NPO CKTI».The tests carried out made it possible to verify the operability of the acquired HD, to determine the dependence of the HD power on the rotation frequency, the dependence of the cooling water flow rate on the HD power and the dependence of the HD power on the steam flow rate to the steam turbine drive.The results obtained indicate that the HD of type CFT-9.0 manufactured by «Fuchino Co Ltd» can be recommended as a hydrodynamic power absorber with its high-precision measurement in a wide range of rotation speed, modes and power consumption up to 8.5 MW.


2021 ◽  
Vol 263 ◽  
pp. 02031
Author(s):  
Dilshod Bazarov ◽  
Irina Markova ◽  
Sanatjon Khidirov ◽  
Oybek Vokhidov ◽  
Farokhiddin Uljaev ◽  
...  

The paper analyzes the dynamics of planned and deep deformations on the section of the Amudarya River in the area of the damless water intake in the main structure of the Karshi Main Canal-KMC. The results of field studies of the state of the canal situation of the Amudarya River at the site of a damless water intake are studied. The course of riverbed processes in the riverbed is studied. Recommendations for improving water intake conditions have been developed. According to the results of the field survey and the study of the head section of the supply canal, the state of the Amudarya riverbed in the water intake zone was assessed. The results of surveys of the hydraulic and pumping modes of sediments of the Amudarya River in the area of the damless water intake are analyzed and summarized. The results of field studies of the canal situation of the Amudarya River in the water intake area in the Amudarya River KMC in the area of the Karshi head water intake are studied. The riverbed situation is not characterized by constant hydraulic characteristics over time for the same water flow rate, i.e. with the same water horizon marks, the flow rates may differ from each other by about half, and with the same flow rates, the horizon marks may vary up to ± 0.6 m. This is explained by the extreme instability and high mobility of the canal, and large deformations of the canal occur in a short time. The hydraulic regime of the river is characterized by a significant redistribution of speeds, depth and width of the flow. The range of their changes is within: Maximum speed >Vmax =2…5 m/s; average speed Vav = 0.5…2.5 m/s; depth H max = 4…14 m, Hav = 1…5 m; width B = 300…2000 m; slope i = 0.00016…0.0003. It is established that the characteristic feature of the river is that at a constant flow can have different average velocities depth and width, for example, when Qw = 1000 m3/s, respectively, v = 0.6…1.7m/s, B = 180…1030m, Hav = 1.1…4.3m.


Author(s):  
Evan Osborne

Does humanity progress primarily through leaders organizing and directing followers, or through trial and error by individuals free to chart their own path? For most of human history ruling classes had the capacity and the desire to tightly regiment society, to the general detriment of progress. But beginning in the 1500s, Europeans developed a series of arguments for simply leaving well enough alone. First in the form of the scientific method, then in the form of free expression, and finally in the form of the continuously, spontaneously reordered free market, people began to accept that progress is hard, and requires that an immense number of mistakes be tolerated so that we may learn from them. This book tells the story of the development of these three ideas, and for the first time tells of the mutual influence among them. It outlines the rise, and dramatic triumph, of each of these self-regulating systems, followed by a surprising rise in skepticism, especially in the economic context. Such skepticism in the 20th century was frequently costly and sometimes catastrophic. Under the right conditions, which are more frequent than generally believed, self-regulating systems in which participants organize themselves are superior. We should accept their turbulence in exchange for the immense progress they generate.


2021 ◽  
Vol 13 (15) ◽  
pp. 8324
Author(s):  
Viacheslav Morozov ◽  
Sergei Iarkov

Present experience shows that it is impossible to solve the problem of traffic congestion without intelligent transport systems. Traffic management in many cities uses the data of detectors installed at controlled intersections. Further, to assess the traffic situation, the data on the traffic flow rate and its concentration are compared. Latest scientific studies propose a transition from spatial to temporal concentration. Therefore, the purpose of this work is to establish the regularities of the influence of traffic flow concentration in time on traffic flow rate at controlled city intersections. The methodological basis of this study was a systemic approach. Theoretical and experimental studies were based on the existing provisions of system analysis, traffic flow theory, experiment planning, impulses, probabilities, and mathematical statistics. Experimental data were obtained and processed using modern equipment and software: Traficam video detectors, SPECTR traffic light controller, Traficam Data Tool, SPECTR 2.0, AutoCad 2017, and STATISTICA 10. In the course of this study, the authors analyzed the dynamics of changes in the level of motorization, the structure of the motor vehicle fleet, and the dynamics of changes in the number of controlled intersections. As a result of theoretical studies, a hypothesis was put forward that the investigated process is described by a two-factor quadratic multiplicative model. Experimental studies determined the parameters of the developed model depending on the directions of traffic flow, and confirmed its adequacy according to Fisher’s criterion with a probability of at least 0.9. The results obtained can be used to control traffic flows at controlled city intersections.


Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.


2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110208
Author(s):  
Yuan Zhang ◽  
Lifeng Wang ◽  
Yaodong Zhang ◽  
Yongde Zhang

The thermal deformation of high-speed motorized spindle will affect its reliability, so fully considering its thermal characteristics is the premise of optimal design. In order to study the thermal characteristics of high-speed motorized spindles, a coupled model of thermal-flow-structure was established. Through experiment and simulation, the thermal characteristics of spiral cooling motorized spindle are studied, and the U-shaped cooled motorized spindle is designed and optimized. The simulation results show that when the diameter of the cooling channel is 7 mm, the temperature of the spiral cooling system is lower than that of the U-shaped cooling system, but the radial thermal deformation is greater than that of the U-shaped cooling system. As the increase of the channel diameter of U-shaped cooling system, the temperature and radial thermal deformation decrease. When the diameter is 10 mm, the temperature and radial thermal deformation are lower than the spiral cooling system. And as the flow rate increases, the temperature and radial thermal deformation gradually decrease, which provides a basis for a reasonable choice of water flow rate. The maximum error between experiment and simulation is 2°C, and the error is small, which verifies the accuracy and lays the foundation for future research.


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