Studies of the movement of ice through low-pressure waterworks

Passage of ice through hydraulic structures is a significant and urgent issue for study. When examining this issue, various conditions should be taken into account. Thus, the successful passage of ice through hydraulic structures depends both on ice characteristics, the parameters of the spillway structures, and on the ice movement velocity in front of the spillway. The goals have been formed; the research tasks have been set. As a result, a theoretical solution to determine the bending moments necessary for calculating the fracture of ice floes has been obtained. The proposed analytical solution for determining the bending moments is found based on a system solution of differential equations of a rigid body motion in a fluid. The assumptions made for this case are set out in the article. The resulting dependence makes it possible to determine the bending moments in any section of the ice section and take into account the flow dynamics. A complex of laboratory studies was carried out, aimed at studying the ice movement velocities on the developed and manufactured model of a spillway with a wide threshold, in front of which an auxiliary threshold is installed to create a concentrated fall. The dependence for determining the velocity in the form of a trigonometric function is obtained and converted into a convenient formula. The performed calculations are compared with the field data and satisfactory results are given.

Combined solution: the structures of the A120 Little Hadham bypass and flood alleviation scheme

<p>The village of Little Hadham in the UK has suffered from heavy traffic, air pollution and flooding over many years. The village also creates a major bottleneck to traffic flows on the main A120 road through the region, a major east west route crucial for the prosperity of the East of England.</p><p>These multiple issues are being resolved though the construction of a combined bypass and flood alleviation scheme. By combining the resources and requirements of the highway and environmental authorities the scheme provides a sustainable and cost-effective solution to these issues with highway embankments and bridges also acting as flood alleviation dams and spillway structures. These combined benefits ensured the commercial viability of the scheme.</p><p>This paper gives an overview of the structures and design challenges faced and how the requirements of the two functions have been combined into a single solution that ensures the future of Little Hadham and promotes growth in the region as a whole.</p>

Laboratory study of stilling basin using trapezoidal bed elements

When designing dam spillway structures, the most significant consideration is the energy dissipation arrangements. Different varieties of baffle blocks and stilling basins have been used in this context. However, the hydraulic jump form of stilling basin is considered to be the most suitable. The main objective of this research was to introduce four different baffle block shapes (models arranged from A to D, installed at slopes 0.00, 0.04, 0.06 and 0.08 in the stilling basins). To illustrate the consequences for the qualities of pressure-driven bounce, each model was attempted in the bowl. The trials applied Froude numbers between 6.5 and 9.2. The puzzle square model D provided the best outcomes compared to the models A, B, C and smooth. Model D with different models at inclines 0.00, 0.04, 0.06 and 0.08 was used to consider the impacts of perplex hinders on water driven-bounce when bed slants were changed. When the model D baffle used instead of a smooth bed at 0.08 slope, the reduction in y2 / y1 reached 12.8%, and Lj / y1 was 18.9%. Among the different bed slopes, a normal decrease in y2 / y1 ranged from approximately 10.3%, whereas the normal decrease in Lj / y1 was about 13.8% when the model D baffle was used instead of the model A baffle with a horizontal slope bed of 0.00. The results show that the new shapes led to a decrease in sequent profundity proportion and length of jump proportion; however, the energy dissipation proportion increased.

Improvement of methods of calculation of transformation vnutrikletochnogo flood flow

The purpose of the study is to develop a method for calculating flow schedules in the dams ‘ spillway structures, to consider the regularities of the flood flow transformation as a result of exceeding the inflow over the discharge of water into the pond. Given this process in the design of ponds, it is possible to reduce the maximum consumption and, accordingly, reduce the size of the spillway structures and their cost. The object of the study are ponds with small catchment areas, which are characterized by intra-day fluctuations in water flow due to intra-day fluctuations in air temperature and different rates of snow melting during the day. Most of the ponds in the Bryansk region are built on gullies, ravines, streams, very small rivers with small catchment areas, for which it is especially important to improve the methods of calculating the transformation of intraday flood flow and forecasting the shape of hydrographs, the search for the least time-consuming and the most acceptable methods of calculation. The proposed mathematical model allows to optimize the calculations.

Flow kinematics with oppositely rotating coaxial layers

In modern technological processes, liquid and gas flows play an important role. This is especially mostly evident in hydraulic engineering and hydropower construction when designing the highly efficient hydraulic turbines, various spillway systems and other elements of layout patterns of structures. When designing and constructing such facilities, it is necessary to know the characteristics of the flows to be passed through these structures in order to correctly take into account the various types of impacts from the flow: pressure pulsations, cavitation and erosion due to cavitation, wave formation and abrasive wear. When designing high-head spillway structures, special attention is paid to the presence of excess energy from the stream entering the lower pool, which requires special measures to dissipate it. Nowadays, in the practice of construction of hydraulic structures, swirled flows are used including those with oppositely rotating layers. This type of flow creates a number of effects that allow one to radically solve the problems of energy dissipation of high-velocity flows. The report presents the results of studies of a complicated flow formed by oppositely rotating coaxially arranged layers of liquid made by a physical method. The description of the experimental stand for the model studies of such flows is given. The basic parameters of the installation, the principle of operation of the recording equipment and its main characteristics are given. The results of model studies in the form of distribution of the components of the flow velocity along the cross section of the flow conductor and its length are given.