Design of stilling basin for circular pipe outlets

2008 ◽  
Vol 35 (12) ◽  
pp. 1365-1374 ◽  
Author(s):  
Arun Goel
Keyword(s):  
Experimental Work ◽  
Circular Pipe ◽  
Stilling Basin ◽  
Basin Floor ◽  
Pipe Outlet

Experimental work leading to the design of a stilling basin for pipe outlets is reported in this paper. The stilling basin designed on the basis of present study has been compared with the stilling basin design proposed by Garde et al. in 1986. The experiments were performed by taking two pipe outlets of 10 and 7.5 cm diameter and varying inflow Froude numbers. In the present study, the new design is arrived at by conducting a systematic experimentation on the various stilling basin models and keeping the basin floor at the invert level of the pipe outlet. The location as well as the arrangements of appurtenances, such as a wedge-shaped splitter block, modified grid, row of wedge-shaped baffle blocks, and end sill, were also varied in the experiments. A nondimensional number has been defined to compare the performance of the stilling basin models on the basis of developed scour downstream of the basin. The performance of the proposed stilling basin (model M-71) is much better as compared with that of the stilling basin G-D* proposed by Garde et al. in 1986.

scholarly journals AN EXPERIMENTAL AND NUMERICAL STUDY OF FACTORS INFLUENCING THE SCOUR DUE TO THE COLLISION OF WATER JET IN STILLING BASIN FLOOR

2019 ◽  
Vol 10 (2) ◽  
pp. 42-59
Author(s):  
Fadhil Al- Mohammed ◽  
◽  
Ali Jassim ◽  
Hamid Abbas ◽  
◽  
...  
Keyword(s):  
Numerical Study ◽  
Water Jet ◽  
Stilling Basin ◽  
Factors Influencing ◽  
Basin Floor

Hydraulic design for the two-stage stilling basin

1981 ◽  
Vol 8 (2) ◽  
pp. 137-145
Author(s):  
C. D. Smith ◽  
M. J. Klassen
Keyword(s):  
Three Dimensional ◽  
Design Criterion ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Two Stage ◽  
Stilling Basin ◽  
Hydraulic Design ◽  
In Series ◽  
Basin Floor ◽  
High Head

The two-stage stilling basin is a design sometimes used for high head energy dissipating structures. The distinguishing feature of the design is that essentially two hydraulic jumps occur in series in the same structure. The tailwater depth for the first jump is created by a fixed weir. Tailwater for the second jump is due to the natural tailwater available in the downstream channel. Since most of the energy of flow is dissipated in the first jump, the required tailwater depth to produce a jump in the second basin is considerably decreased, with the result that the entire stilling basin floor may be placed at a higher elevation than for a single basin. This can be advantageous in certain situations.In this paper the results of hydraulic model tests for a two-stage stilling basin are reported. The characteristics of the basin first were studied two-dimensionally using a parallel sided flume. A design criterion was established and this was subsequently verified on a three-dimensional model.

Application and Comparsion of Mathematical and Physical Models on Inspecting Slab of Stilling Basin Floor under Static and Dynamic Forces

2011 ◽  
Vol 147 ◽  
pp. 283-287 ◽  
Author(s):  
Behzad Mohammadzadeh ◽  
Mahmoud Bina ◽  
Hooshang Hasounizadeh
Keyword(s):  
Hydraulic Jump ◽  
Physical Models ◽  
Stress And Strain ◽  
Floor Slab ◽  
Stilling Basin ◽  
Dynamic Forces ◽  
Basin Floor ◽  
Energy Dissipated ◽  
Physical And Mathematical Models ◽  
Resultant Forces

To protect downstream of hydraulic structures against erosion and degradation, must dipress water energy. one of the most comon methods to achive this purpose is constructing the stilling basin at the downstream of such structures. In stilling basin, the water energy dissipated by taking place of hydraulic jump. When a hydraulic jump occurs, the hydrodynamic and hydrostatic forces effect on the stilling basin floor slab. These forces include the force due to water weight and the up lift force affected the slab below which these forces are classified in hydrostatic. also the other force is hydrodynamic force due to pressure fluctions below the hydraulic jump. To keep the stilling basin stabillity from liffting up and destruction must the resistant forces be equal to destroyer forces. In this study after discution about the hydraulic jump and its resultant forces, a equation has been offerd to determine the thickness of stilling basin floor slab using buckingham theory andsoftware DATAFIT. Finaly the slab which evaluated by physical model, simulated using mathematical model(software ANSYS 10) and studied. The stress and strain diagrams were extracted. Results showed that physical and mathematical models were matched very good.

EXPERIMENTAL STUDY OF STILLING BASIN MODELS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Hari Lal Tiwari ◽  
Kamal Singh
Keyword(s):  
Hydraulic Structure ◽  
Base Material ◽  
Model Design ◽  
Flow Conditions ◽  
Number Range ◽  
Stilling Basin ◽  
New Models ◽  
Stilling Basins ◽  
Sand Base ◽  
Pipe Outlet

Stilling basins with appurtenances can be used effectively in dissipating the excessive energy downstream of hydraulic structure like spillway, sluices, pipe outlets etc. Experimental investigation leading to the development of new stilling basin model design for pipe outlet with different appurtenances is reported in this paper. On the basis of present study, newly stilling basin design has been compared with USBR VI model. The new models were tested in a rectangular shaped pipe outlet for three Froude numbers, namely Fr = 1.85, 2.85, and 3.85 in comparison to USBR VI stilling basin model recommended for the pipe outlets. The scour pattern was measured for each test run and flow pattern was also observed. The performance of the basin was compared by Performance number (PN) as criteria to evaluate the performance of model, using same sand base material and test run time for all the tested models. After test runs, it is found that, for a given Froude number range, the performance of new stilling basin model is improved and also the length of the newly developed basin is reduced as compared to USBR VI stilling basin for a given flow conditions.

scholarly journals A Simplified Numerical Approach to Examine the Sensitivity of Two-Electrode Capacitance Sensor Orientation to Capture Different Gas–Liquid Flow Patterns in a Small Circular Pipe

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4971
Author(s):  
Fayez M. Al-Alweet ◽  
Artur J. Jaworski ◽  
Yusif A. Alghamdi ◽  
Zeyad Almutairi ◽  
Jerzy Kołłątaj
Keyword(s):  
Liquid Flow ◽  
Experimental Work ◽  
Performance Optimization ◽  
Flow Patterns ◽  
Circular Pipe ◽  
Capacitance Sensor ◽  
Numerical Work ◽  
Sensor Orientation ◽  
Electrode Capacitance ◽  
Gas Liquid Flow

This work involved the simulation of both a multiphase gas–liquid flow and the electromagnetic field representing a two-electrode capacitance sensor in a circular pipe. The simulation investigates in particular the sensitivity of the sensor orientation around the pipe (i.e., top-to-bottom or side-to-side) that best capture the induced flow patterns. The presented numerical work is a simplified simulation by COMSOL multi-physics which was validated by a systematic and an extensive experimental work, using (a) a specially designed simple capacitance sensor (i.e., concave two electrodes), (b) different gas–liquid superficial velocity combinations, (c) different flow section inclinations, and (d) high-speed camera images. The numerical modelling capacitance values were validated against the experimentally measured values which shows a satisfactory level of agreement with a deviation of less than ±2%. The quantity of finite points was between 280,000 and 340,000, which was influenced by the simulated flow pattern. The simulated cases captured the generated flow patterns and their variation inside the pipe, which was in a good agreement when compared to the experimental work as time-dependent values. It was found that the best orientation for the utilized two-electrode capacitance sensor was the top-to-bottom configuration. This is because the sensor’s electrical field distribution was more sensitive, and capable of detecting a greater range of capacitance values. The sensitivity of the top-to-bottom configuration was 1.25–1.64 times greater than that of the side-to-side configuration. Therefore, for design purposes and performance optimization, it is recommended to use the top-to-bottom configuration.

scholarly journals Investigation Of Hydraulic Flow Characteristics On Drop Structures

2021 ◽  
Vol 930 (1) ◽  
pp. 012028
Author(s):  
V Dermawan ◽  
D R Dermawan ◽  
M J Ismoyo ◽  
P H Wicaksono
Keyword(s):  
Flow Behavior ◽  
Flow Characteristics ◽  
Ground Level ◽  
Flow Depth ◽  
Stilling Basin ◽  
Flow Parameters ◽  
Jump Length ◽  
Gradient Channel ◽  
Basin Floor ◽  
Free Falling

Abstract Drop structures are required if the slope of the ground level is steeper than the maximum allowable gradient channel. Drop structures become bigger as height increases. Its hydraulic capability may be reduced due to variations of jets falling on the stilling basin floor due to discharge changing. Drop structures should not be used if the change in energy level exceeds 1.50 m. The free-falling overflow on drop structures will hit the stilling basin and move downstream. As a result of overflows and turbulence in the pool below the nappe, some energy is dissipated at the front. The rest of the energy will be reduced downstream. The objectives of this study are to investigate the hydraulics flow behavior in straight and sloping drop structures and to investigate hydraulics flow behavior in a single and serial vertical drop (stepped drop). The hydraulic model results of single and stepped drop structures are compared to obtain flow behavior and energy dissipation information. The comparisons are specific to the flow parameters, including flow depth at the drop structures toe, flow depth after the jump, and hydraulic jump length.

Research into the Effect of Photometric Flicker Event on the Perception of Office Workers

2019 ◽  
pp. 22-27
Author(s):  
Cenk Yavuz ◽  
Ceyda Aksoy Tırmıkç ◽  
Burcu Çarklı Yavuz
Keyword(s):  
Experimental Work ◽  
Psychological Problems ◽  
Office Workers ◽  
Questionnaire Study ◽  
Fast Growing ◽  
Lighting Conditions ◽  
Lighting Systems ◽  
Enormous Number

Today the number of office workers has reached to an enormous number due to the fast-growing technology. Most of these office workers spend long hours in enclosed spaces with little/no daylight penetration. The lack of daylight causes physiological and psychological problems with the workers. At this point lighting systems become prominent as the source and the solution of the problem. Photometric flicker event which arises in the lighting systems can sometimes become visible and brings a lot of issues with it. In this paper, an experimental work has been done to investigate the effect of flicker. For this purpose, the flicker values of 3 different experiment rooms for different lighting conditions and scenarios have been measured and a questionnaire study has been carried out in the experiment rooms with 30 participants. In conclusion, the effect of the flicker event on the volunteers have been classified and some methods have been proposed not to experience flicker effects.

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