High-head spillway system with a countereddy energy dissipator

Abstract

The design of a spillway, called a countereddy spillway, was,proposed and investigated at the V. V. Kuibyshev Moscow Civil Engineering Institute (MISI).The spillway (Fig. i) consists of an inlet pressure conduit 1 from which branch six conduits 2 of smaller diameter conveying water to a cylindrical chamber 7 separated by a deflector 6. The chamber with a length of 2-3 diameters passes into the outlet conduit, which can be both pressure and freeflow. The water is delivered to the chamber by conduits 2 tangentially, whereupon three conduits (section A-A) swirl the flow in one direction and the other three (section B-B) in the opposite direction.Both swirled flows, by-passing the separating deflector 6, enter the chamber, where their interaction and intense dissipation of the energy of the swirl (kinetic and pressure energy) occur. Also provided for is the entry of an axial flow into the dissipation chamber through conduit 3, which should promote stabilization of the flow and reduction of cavitation phenomena.Conduits 2 and 3 are equipped with gates 4, which can be in two positions:closed or completely open. There is also an air duct with a gate 5 through which air can be fed into the central part of the flow. The discharge is regulated by bringing into operation a various number of tangential conduits 2.An important advantage of such a spillway compared to the scheme of separating and joining two swirled flows [i] is that the zone of intense interaction of the two flows is located within the common flow and does not close up on the walls of the dissipation chamber, which eliminates the danger of occurrence of dynamic actions on the spillway structure.The swirled flows increase the pressure on the chamber walls within the limits of the deflector and tangential inlets, which promotes a decrease of velocity and prevents the occurrence of cavitation.The energy is dissipated on a short length of chamber 7.

Dynamics of laminar flows with coaxial oppositely-rotating layers

“…Начало исследования контрвихревых течений было положено разработкой водосбросов высоко- напорных гидроузлов [1,2]. К настоящему времени контрвихревые течения, в которых в турбулентном диапазоне существенно интенсифицируются процессы массо-, энерго-и теплопереноса, применяют в технологиях, требующих получения высокодисперсных смесей или повышения эффективности теплообмена [3][4][5][6][7][8][9][10][11][12][13][14].…”

“…На рис. 2 можно видеть, что принятое выше на основе экспериментальных данных [1,2,22,30] допущение о возможности пренебречь в уравнениях динамики вязкой жидкости радиальной составляющей скорости u r (но не в уравнении неразрывности, поскольку в этом случае нарушается баланс масс) находит аналитическое подтверждение.…”

Hydrodynamic structure of laminar flows with oppositely-swirled coaxial layers

“…1). Such flows in the Russian-language technical and normative literature are called "contrvihrevie" [1][2][3][4][5]. The work is based on article [6] devoted to the description of the flow kinematic structure.…”

“…The relevance of the topic is related to the fact that the flows with oppositely swirling coaxial layers in the turbulent range are characterized by intensive mixing (diffusion) and quenching (dissipation) of the mechanical energy of the moving viscous media. Both properties of such flows have a great potential for practical use [4,7]: the first -in technologies involving the mixing of heterogeneous and multiphase media in microbiology, chemistry, ecology, heat engineering, power engineering, engine and rocketengineering; the second -to dissipate the mechanical energy of the flow of liquid or gas, for example, in high-pressure hydraulic spillways [1,2,8,9] or for suppressing the noise of aircraft engines, propellers of ships. The effective development of these technologies is impossible without knowledge of the hydrodynamics of such flows.…”