Sector Gate Research Articles

An Experimental Study of Flow and Turbulence Properties near the Rising Sector Gate Mouth Considering the Gate Opening with a PIV Measuring System

Hydraulic structures, such as movable weir gates, are widely installed in rivers and streams for various purposes. Among these is the rising sector gate, which is the focus of this study. This research investigated how different gate openings affect flow velocity and turbulence distributions at the gate mouth. A hydraulic analysis of flow and turbulence characteristics near the mouth of a rising sector gate model was conducted through laboratory experiments with various flow conditions and gate openings utilizing a Particle Image Velocimetry (PIV) system. Experimental tests were carried out with two gate-opening angles (30 and 45 degrees). The PIV measurements revealed significant variations in flow velocity and turbulence properties in response to the gate openings and flow conditions. Notably, in the vicinity of the gate mouth, where the flow regime changes rapidly between the upstream and downstream regions, the turbulence properties in the upstream part of the gate mouth were more than twice those in the downstream part. Additionally, the streamwise distribution of depth-averaged relative turbulence intensity was analyzed. The results showed that the depth-averaged relative turbulence intensity decreased by nearly half as the gate opening increased from 30 to 45 degrees, with the lowest values observed at the gate mouth, followed by an increase downstream. A functional relationship between the maximum flow velocity at the gate mouth during underflow operation and the Froude number was established to guide practical gate operation in the field.

Experimental and numerical study on static performance of ship lock sector gates

A sector gate is a fundamental type of lock gate. It is designed as a large cantilevered, rotatable space truss structure capable of withstanding bidirectional hydraulic pressures and operating under dynamic water conditions. This makes it prevalent in medium- and large-scale navigation locks. This research examines the structural behavior of a ship lock sector gate using one in-situ test and two numerical models. The sector gate, with an 11.72-m span, consists of a panel beam system, space truss system, boundary column, and floating box. An in-situ test was conducted to obtain the stress and deformation of key components of the sector gate under positive hydraulic head difference conditions during regular operation. A finite element model was established, verified, and a model updating framework incorporating sensitivity analysis based on the Hooke-Jeeves direct search method was established. The updated model was employed to perform an in-depth examination of the gate's mechanical characteristics under extreme conditions of both positive and negative hydraulic head. The findings suggest that the most crucial region is situated at the intersection of the boundary column and the bottom struts. The stress and displacement responses of the components exhibit a positive correlation with water depth, with the struts and truss chords experiencing significant stress. The entire gate demonstrates twisting along the longitudinal axis of the lock chamber, which negatively impacts its ability to seal effectively. These findings provide valuable insights for the design of sector gates, contributing to the safe operation of gates and efficient navigation of waterways.

Operating Force Characteristics of Sector Gates Based on Prototype Testing

With the widespread use of sector gates in tidal river locks, there is a growing interest in the operating force during the gate operation. This study investigates the characteristics of operating forces in a sector gate hydraulic cylinder system using prototype testing and focuses on the effects of different heads and flow velocities under the operating forces. The results reveal significant differences in the opening processes between normal and reverse heads, with head differentials and direction playing crucial roles in determining the operating force under flowing conditions. In still water, both gate opening and closing processes are divided into four and three stages, respectively, with the operating force remaining stable during the low-force operation stage. In particular, during gate closure under flowing conditions, flow velocity emerges as a key factor influencing the operating force, with the force during the small gate opening stage exhibiting a parabolic relationship with flow velocity. These findings provide valuable insights for the design and selection of hydraulic gate control systems, contributing to the safe operation of gates and efficient navigation of waterways.

Hydrotechnický výzkum kapacity sektorového uzávěru

The article deals with the hydraulic and structural assessment of a sector gate in Děcin and Ceský Krumlov based on the evaluation of experimental measurements performed on a physical hydraulic model In the Water Management Laboratory of the Faculty of Civil Engineering, CTU in Prague.

Structural Dynamic Analysis of the Chenderoh Dam Sector Gate Section

The dynamic characteristics such as natural frequencies, mode shapes and frequency response function (FRF) are the important characteristics to be investigated to access the level of durability of any dam structures. These characteristics are important since it will be the reference information for any operational methods to be used for the dam structures. In this study, one of the real dam (i.e., Chenderoh Dam) that available in Malaysia is taken into consideration, where the dynamic analysis of the sector gate section of the dam structure is investigated. the real scale of the sector gate section is measured on site and modelled into the CAD software with the consideration of real build-in materials. Then, the finite element (FE) model is constructed in ANSYS software with the required boundary condition and meshing sensitivity analysis. From the result of modal analysis, 30 natural frequencies are determined in the range of 0.5904 Hz to 8.471 Hz together with the mode shapes but only the most significant natural frequencies will be shown in this paper. In addition, all three axes of the FRF graphs show an agreement for the highest natural frequency value at 7.95 Hz, where the maximum deflection occurred in x axis direction with 2.03 × 10-7 m.

A new PROFIBUS interface for vacuum sector gate valve controllers

The vacuum control systems of the accelerators complex at CERN are based on PLCs, which communicate with controllers either with direct inputs or outputs, or via PROFIBUS. In order to improve the efficiency of the sector valve controller communication, a low cost PROFIBUS interface card has been designed. This paper presents the developed hardware and firmware, together with the corresponding assessment tests. It flags the improvements of this new interface, in comparison with the former system. Furthermore, this paper can be helpful for any custom design that needs a PROFIBUS interface.

A discrete optimization process for the design of horizontal girders of rising sector gate using PIAnO

Many small dams have recently been constructed on several major rivers in the Republic of Korea to utilize these water resources and control water flows. One such water body is the Gangjeong reservoir in the Nakdong River; a rising sector gate was mounted on this reservoir. The finite element analysis (FEA) confirmed the empirical design of the gate to be safe with minor modifications. However, the positions of the horizontal girders are critical in the design of a gate, and it is must be determined by a trial-and-error process. To find the optimal solution for the positions and thicknesses of horizontal girders in a rising sector gate, this paper proposed a new procedure using the commercial optimization package, PIAnO, as well as Pro-Engineer, Hypermesh, and Abaqus. The optimal positions of the horizontal girders are selected from 9 predefined positions. A special technique was developed and applied to change the discrete position set, such as (1, 4, 8) to a continuous dimensionless variable. For this, a FORTRAN program was written to convert the dimensionless variable to a set of position numbers, and vice versa.

Concept Designs of Headstock Gear for Large-Span Gate

Large-span gates with the width of 60m~120m were planed in a lake of China. This paper describes concept designs of headstock gears available in sandy-freshwater. Locomotive engine, with hydraulic-motors & gears, was the selection to drive the floating sector gate; The V-rotating gate was driven by rods or hydraulic-motors.

Analysis of Vibration Mode of Hydraulic Gate Structure

It is generally existed that the vibration problem of hydraulic gate structure during water conservancy project, whose vibratory magnitude is closely related to inherent feature of gate structure and spectrum signature of hydrodynamic loads. In this project, through contrastive analysis of modal test procedure of multi-support excitation and single-point response as well as finite element computational analysis, test model and finite element model of some hydraulic sector gate had been built to indicate the results of modal test were basically close with that of finite element model, the changing frequency being the same. Both of them could truly reflect the dynamic characteristics of gate, which proved it effective that the methods for researching on vibration modes of hydraulic gate adopted and provided important basis for further dynamics research and design optimization.

YACHT HARBOURS IN THE UNITED KINGDOM

The authors describe the introduction and development of commercial yacht harbours in the United Kingdom. In the case of the south and west coasts where there is a high mean spring tidal range of up to 8 metres, this has resulted in the provision of enclosed basins, provided with either some form of gate or sill to retain the water. These are described, with typical examples. Recent developments in the design of sector gates are reviewed.

THE THAMES BARRIER

An area of over 100 km2 of industrial and residential property was at increasing risk from flooding, including some 700,000 residents and the central section of the underground railway. Attention was drawn to this risk in a 1966 report by Sir Herman Bondi, and the GLC was empowered by the Thames Barrier Act of 1972 to construct a barrier at Woolwich Reach, 13 km downstream from London Bridge. The alternatives of a barrier and a barrage were examined, and the final design employs rising sector gates, providing four main navigation opening each of 61 m, and a further six of 31 m. Rotation of the gates is by radius arms, driven from hydraulic cylinders, with three 140 kW pump power packs on each of the principal piers. The site is provided with three independent sources of electric power, connected to the piers via duplicated access tunnels. For the construction there were three main and 20 other contractors, and site work began in 1975, erection of the gates in 1980, and the barrier was first completely closed in 1982. The projects passed through three stages: feasibility, detailed design and contract letting, and construction and commissioning. The project was controlled through monthly site meetings. Total cost escalated from £110 × 106 at 1973 prices to £440 × 106 on completion in 1984, which has to be set against the estimate of £5000 × 106 as the cost of a major flood disaster.

Two-Component Force-Balance

This note describes a simple two-component balance, designed, fabricated, and used by the writers to measure the fluctuations in the horizontal and vertical components of water forces on a sector gate. Details of the two component balance are given. Static calibration curves for horizontal forces in two directions and for vertical forces are presented. The two-component balance described in this note can be used for simultaneous but separate measurement of two mutually perpendicular components of dynamic forces of low frequency and static forces. The capacity, sensitivity, and range of reliable frequencies can be suitably altered by altering the stiffness and mass of the system. The principle can be extended to three component balances also.

Sector Gates in Bangkok Klong System

Bangkok, Thailand is interlaced with an integrated network of canals. Under the present modernization program, these canals will be developed such that navigation lock and control gate structure installations will be needed to provide for navigation, flushing and pollution control. Because Bangkok is situated in a tidal area reversing heads will act on the lock and control structure gates. And because of this function, and for operational and economic factors, sector gates were selected for the lock and gate installations.

Compuertas de sector para aliviadero de superficie, en (U.S.A.)

The spillway of the Wanapum dam, on the Columbia (U. S. A.), includes 12 sector gates, designed by the Harza Engineering Company Each gate closes an opening of 15 x 20 m. The hinges of the gates are supported by reinforced concrete blocks, suitably anchored on the top side of the dam, by means of 14 cables, each made up of 90 wires of 6.35 mm diameter. This avoids the use of heavy metal structures, normally necessary to withstand the thrust of the gates. The anchorage blocks and the main supporting piles contain grooves, into which the gate hinges, one on each side of each anchorage block, are located. The determination of the three dimensional stress distribution in these anchorage blocks was carried out on reduced scale models, in which aluminium was used. Other models were studied by photoelastic methods. These analyses enabled to decide the best shape and internal distributed of the reinforcement. The disparity between the results obtained on the aluminium models and in the photoelasticity investigations were negligeable.

尼崎港水門の陰極防蝕について

尼崎港水門の陰極防蝕について

Line Load Action on Thin Cylindrical Shells

The object of this paper is the derivation of influence numbers for the longitudinal edge deformations of a thin, cylindrical, shell sector, rigidly held between transverse stiffening members. This problem is of practical importance in the design of modern shell structures, such as large pipe lines, self-supporting flume structures, sector gates, and the barrel type of roof described in this paper. The monolithic action of longitudinal stiffening members, as well as the analysis of discontinuous surface loads, leads to the consideration of corrective line loads, which restore the continuity of the structure.