scholarly journals Design of A Streamwise-Lateral Ski-Jump Flow Discharge Spillway

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1585 ◽  
Author(s):  
Jun Deng ◽  
Wangru Wei ◽  
Zhong Tian ◽  
Faxing Zhang
Keyword(s):  
Side Wall ◽  
Hydraulic Engineering ◽  
Limited Area ◽  
Lateral Direction ◽  
Flow Discharge ◽  
Free Jet ◽  
Plunge Pool ◽  
New Type ◽  
Solid Walls ◽  
Large Discharge

Spillway outlet design is a major issue in hydraulic engineering with high head and large discharge conditions. A new type of design for a streamwise-lateral spillway is proposed for ski-jump flow discharge and energy dissipation in hydraulic engineering. The water in the spillway outlet is constrained by three solid walls with an inclined floor, a horizontal floor on the bottom and a deflected side wall in the lateral direction. The water flow releases in a lateral direction into the plunge pool along the streamwise direction. It generates a free jet in the shape of “∩” in a limited area, causing the water to fully diffuse and stretch in the air simultaneously, and drop into the plunge pool to avoid excessive impact in the plunge pool. The formation mechanism for the flow pattern is analyzed, and the results show that the optimum inclination is an angle range of 30°~45° for a good performance of free ski-jump jet diffusion shape.

Modeling Free Jet Trajectory at an Overfall and Resulting Shear Stress Distribution in the Plunge Pool

1993 ◽  
Vol 36 (5) ◽  
pp. 1309-1318 ◽  
Author(s):  
A. W. Fogle ◽  
J. C. McBurnie ◽  
B. J. Barfield ◽  
K. M. Robinson
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Shear Stress Distribution ◽  
Free Jet ◽  
Plunge Pool ◽  
Jet Trajectory

scholarly journals Impact pressure distribution of inverted arch plunge pool for large discharge

2019 ◽  
Vol 20 (1) ◽  
pp. 209-218
Author(s):  
Yu Wang ◽  
Yaan Hu ◽  
Jinde Gu ◽  
Yu Peng ◽  
Yang Xue
Keyword(s):  
Pressure Distribution ◽  
High Water ◽  
Impact Pressure ◽  
Engineering Practice ◽  
Plunge Pool ◽  
Novel Approach ◽  
Water Head ◽  
Relative Errors ◽  
The Impact ◽  
Large Discharge

Abstract In view of high water head and large discharge in the release structures of hydraulic projects, the inverted arch plunge pool has been put forward due to higher overload capability and stability. Impact pressure on the bottom is a serious concern in design safety precautions, however, the quantitative impact pressure distribution in the inverted arch plunge pool is not yet elucidated. In this study, a novel approach is presented to estimate the impact pressure of an inverted arch plunge pool. Impact pressure characteristics are experimentally investigated under different hydraulic conditions. The results detailed the effect of relative discharge coefficient and the deflection angle relative to the vertical central axis of the plunge pool bottom. The predicting formulas of impact pressure distribution are derived within small relative errors, and the proposed approaches have good applicability in three case studies. The achievements of this investigation are used to define issuance parameters relevant for engineering practice.

Gravitational Flow Discharge From a Horizontal Duct

1985 ◽  
Vol 52 (1) ◽  
pp. 167-171 ◽  
Author(s):  
P. Chan ◽  
T. Han ◽  
W. L. Chow
Keyword(s):  
Initial Pressure ◽  
Unknown Boundary ◽  
Physical Plane ◽  
Flow Discharge ◽  
Free Jet ◽  
Gravitational Flow ◽  
Total Head ◽  
Boundary Functions ◽  
Hodograph Plane ◽  
Hodograph Transformation

The problem of a potential flow discharge through a two-dimensional horizontal duct under the influence of gravitation is examined by the method of hodograph transformation. The stream function is considered and established in the hodograph plane, and the solution in the physical plane is established through additional integrations. The unknown boundary functions of the free jet must be determined as part of the solution. The initial pressure level and the discharge characteristics between the total head and the flow rate, have been established. Results are compared with those obtained previously by other method.

Dynamic Switching Study on Fluidic Component of Fluidic Sprinkler

2011 ◽  
Author(s):  
Chao Wang ◽  
Hong Li ◽  
Chao Chen ◽  
Qin Tu ◽  
Qianglong Yun
Keyword(s):  
Transient Flow ◽  
Pressure Fluctuations ◽  
Side Wall ◽  
Switching Process ◽  
Driving Mechanism ◽  
Dynamic Switching ◽  
New Type ◽  
Fluidic Control ◽  
Mutual Conversion ◽  
Velocity Turbulence

The fluidic sprinkler controlled by clearance is a new type of water-saving and energy-conservation sprinkler. Different from traditional impact rotating sprinkler, a fluidic component is applied in the fluidic sprinkler, which serves not only as a discharge substance, but also as a driving mechanism instead of a complicated impact-drive mechanism. The mutual conversion between straight spray state and stepping state makes the sprinkler running. The investigation of the flow inside the fluidic component in the switching process and the stepping frequency of the sprinkler are the foundations to learn the law of fluidic control and to optimize the performance of the fluidic sprinkler. This paper carries out the simplified prototype of the fluidic component, measures the pressure distribution on the side wall under static attachment state and the pressure fluctuations during the dynamic switching process. The discrepancy between the results indicates that, previous researches on static attachment state are not applicable in switching process. The simulation of dynamic switching is carried out by UDF self-programming method with the experimental results as boundary conditions. The transient flow in the dynamic switching process is studied roughly. The distributions of the pressure, velocity, turbulence kinetic energy have been obtained.

Applicability of Reichardt's Hypothesis to the Prediction of Velocity Field of Multiple Parallel Plane Jets

2010 ◽  
Vol 26 (2) ◽  
pp. N17-N22
Author(s):  
A. Nasr ◽  
J. Lai
Keyword(s):  
Velocity Field ◽  
Parallel Plane ◽  
Center Line ◽  
Lateral Direction ◽  
Free Jet ◽  
Plane Jets ◽  
The Individual ◽  
Theoretical Results ◽  
Good Agreement ◽  
Made In

AbstractIn this paper the velocity distribution for multiple parallel plane jets based on the superposition of Reichardt's solution for single free jet is derived. The extend of the applicability of Reichardt's hypothesis to prediction of multiple parallel plane jets is examined. Both ventilated and unventilated two parallel plane jets data published in the literature and obtained for this study were used for comparisons with the theoretical results obtained from Reichardt's hypothesis. LDA measurements of mean streamwise velocities and turbulence characteristics of an array of 5 parallel plane jets were also made in order to establish the conditions under which this heuristic approach is valid. Results show that provided the pressure gradient in the lateral direction is small and hence the deflection of the individual jet center line is small, there is a good agreement between experimental results and predictions based on Reichardt's hypothesis for multiple parallel plane jets.

The Structural Design and Analysis of the New Type of Gripper

2016 ◽  
Vol 693 ◽  
pp. 269-274
Author(s):  
X.H. Shi ◽  
Shou Cheng Wang
Keyword(s):  
Structural Design ◽  
Design Theory ◽  
Hydraulic Engineering ◽  
Front End ◽  
New Type

The reason of lacking of a suitable front-end actuator when excavators moving massive objects, a new type of hydraulic engineering gripper was designed. Its design theory was showed. The use of SimulationXpress in the Solidworks to optimize the design, made the structure of cured rod more reasonable.

scholarly journals Seismic running safety of trains and a new type of seismic-isolation railway structure

2021 ◽  
Author(s):  
Xiu Luo
Keyword(s):  
Safety Assessment ◽  
Seismic Isolation ◽  
Inertial Force ◽  
Longitudinal Direction ◽  
3D Numerical Simulation ◽  
Lateral Direction ◽  
Pendulum System ◽  
Running Safety ◽  
New Type ◽  
Friction Pendulum

Abstract Until now, seismic-isolation structures have not yet been applied in the railway field. The reason is that though a seismic-isolation structure can reduce the inertial force to the structure, the energy absorption causes big response displacement on the structure, which adversely effects the running safety of the trains supported by the structure. In this paper, a methodology for seismic running safety assessment is introduced, and a new type of seismic-isolation foundation is proposed, which can convert the seismic response displacement in the lateral direction of track to the longitudinal direction that has a less adverse effect on the running safety of the train. The isolation foundation is composed of FPS (Friction Pendulum System) slider, concave plate and guide ditch. Moreover, through model experiments and 3D numerical simulation, it is verified that the proposed foundation can keep both the effects of the seismic isolation and the running safety of the train during an earthquake.

scholarly journals The analysis of a jet structure inside a reverse chamber

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1357-1365
Author(s):  
Robert Klosowiak ◽  
Jaroslaw Bartoszewicz ◽  
Rafal Urbaniak
Keyword(s):  
Flat Surface ◽  
Side Wall ◽  
Jet Flow ◽  
Experimental Results ◽  
Test Results ◽  
Velocity Fluctuations ◽  
Free Jet ◽  
The Mean ◽  
Axisymmetrical Jet ◽  
Jet Structure

The paper presents experimental results for an axisymmetrical jet flow impinging with outflow through a reverse chamber. The test results include the average distributions and fluctuations of pressures on the impinged wall and the side wall of the chamber. The presented results cover further the mean velocities and the velocity fluctuations in the reverse chamber in relation to two velocity components: axial and radial. The purpose of the paper is to indicate the differences between different flow situations: the axisymmetrical free jet, the impinging jet hitting a flat surface, and a flow geometrically alike, however, restricted in outflow through a reverse annular chamber.

Flows in Rotation Cylinder Filled With Polymer Solutions

2006 ◽  
Author(s):  
Jae Won Kim ◽  
JaeMin Hyun ◽  
Eun Young Ahn
Keyword(s):  
Apparent Viscosity ◽  
Polymer Solutions ◽  
Side Wall ◽  
Velocity Shear ◽  
Working Fluid ◽  
Shear Rates ◽  
Ctab Solution ◽  
Applied Shear Stress ◽  
Shear Front ◽  
Solid Walls

This investigation deals with the spin-up flows in a circular container of aspect ratio, 2.0. Shear front is generated in the transient spin-up process of the present flow system and it is propagating from the side wall to the central axis in a rotating container. Propagation of the shear front to the axis in a rotating container means the region behind the shear front acquires an angular momentum transfer from the solid walls. Propagating speed of the shear front depends on the apparent viscosity of polymer solution. Two kinds of polymer solutions are considered as a working fluid: one is CMC and the other is CTAB solution. CMC solution has larger apparent viscosity than that of water at the present applied shear stress, and CTAB shows varying apparent viscosities depending on the applied shear rates. Transient and spatial variations of the apparent viscosities of the present polymer solutions (CTAB and CMC) cause different propagating speeds of the shear front. In practice, CMC solution that has larger values of apparent viscosity than that of water always shows rapid approach to the steady state in comparison of the behavior of the flows with water. However, for the CTAB solution, the propagating speed of the shear front changes with the local magnitude of its apparent viscosity. Consequently, the prediction of Wedemeyer’s including viscosity in the propagating speed of the velocity shear front quantitatively agrees with the present experimental results.

Computational modeling of the flow in a wind tunnel

2018 ◽  
Vol 90 (1) ◽  
pp. 175-185 ◽  
Author(s):  
Mahmood Khalid ◽  
Khalid A. Juhany ◽  
Salah Hafez
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Computational Modeling ◽  
Stokes Equations ◽  
Side Wall ◽  
Simultaneous Application ◽  
Content Type ◽  
Wall Boundary Layer ◽  
Wall Boundary ◽  
Solid Walls

Purpose The purpose of this paper is to use a computational technique to simulate the flow in a two-dimensional (2D) wind tunnel where the effect of the solid walls facing the model has been addressed using a porous geometry so that interference arriving at the solid walls are duly damped and a flow suction procedure has been adopted at the side wall to minimize the span-wise effect of the growing side wall boundary layer. Design/methodology/approach A CFD procedure based on discretization of the Navier–Stokes equations has been used to model the flow in a rectangular volume with appropriate treatment for solid walls of the confined volume in which the model is placed. The rectangular volume was configured by stacking O-Grid sections in a span-wise direction using geometric growth from the wall. A porous wall condition has been adapted to counter the wall interference signatures and a separate suction procedure has been implemented for reducing the side wall boundary layer effects. Findings It has been shown that through such corrective measures, the flow in a wind tunnel can be adequately simulated using computational modeling. Computed results were compared against experimental measurements obtained from IAR (Institute for Aerospace, Canada) and NAL (National Aeronautical Laboratory, Japan) to show that indeed appropriate corrective means may be adapted to reduce the interference effects. Research limitations/implications The solutions seemed to converge a lot better using relatively coarser grids which placed the shock locations closer to the experimental values. The finer grids were more stiff to converge and resulted in reversed flow with the two equation k-w model in the region where the intention was to draw out the fluid to thin down the boundary layer. The one equation Spalart–Allmaras model gave better result when porosity and wall suction routines were implemented. Practical implications This method could be used by industry to point check the results against certain demanding flow conditions and then used for more routine parametric studies at other conditions. The method would prove to be efficient and economical during early design stages of a configuration. Originality/value The method makes use of an O-grid to represent the confined test section and its dual treatment of wall interference and blockage effects through simultaneous application of porosity and boundary layer suction is believed to be quite original.

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