The Mini Flow Channel in made of clear acrylic with an undershot weir at inlet and an overshot weir at discharge. Flow rate can be controlled by a flow control valve of the Hydraulics Bench. A dye injection system is installed at the channel inlet to observe flow patterns around models. Mini Flow Channel equipment demonstrates primary characteristics of flow in an open channel including flow patterns over or around immersed objects. It is to be used with Hydraulics Bench. Water is admitted to the channel through a cylinder with a stilling baffle to reduce turbulence. A grid on a white background is provided for easy observation of the streamlines.
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A throttle valve makes it possible to regulate the water flow rate. A series of park-away threaded holes along the bottom of the channel (spaced 250 mm apart) allows to fit the optional models. A guide is assembled on the sides of the channel to carry the accessories and the instruments necessary for the tests. The bottom of the channel can be tilted by up to 1.5 degrees, so as to simulate the normal inclinations of the real channels; it is also possible to obtain a slight negative slope. The centrifugal pump draws the water from the collection tank and transfers it to the still tank, where a manually operated vertical gate, which is assembled before the testing section, allows to vary the height of the hydraulic load. The unit is supplied with manuals that describe each component of the system, installation and utilization procedures, and gives many exercises.
The series of channels has been designed by to study the hydrodynamic phenomena of the open surface streams in variable inclination channels. The following versions are available:
Open Surface Tilting Flow Channel 5 m long
Open Surface Tilting Flow Channel 3 m long
This experimental and demonstration apparatus consists of an open channel of rectangular cross section supported at each end by frames, one of which is adjustable so that the slope of the channel may be varied. This Flow Channel provides a low cost experiment with accuracy comparable with larger scale channel investigations. The channel walls are made from clear acrylic plastic so that full visibility of the flow characteristics can be achieved. A number of test models are provided along with inclinometer and surface profile measuring instrument.
Experimental Capability:
Hydraulic jump - determination of energy head and power loss at the jump section by means of specific energy considerations.
Study of long base weir and calibration of broad crested weir.
Study of Venturi Flume, observation of flow through a throated Flume, calibration of the Flume when used as a flow measuring instrument.
Study of uniform flow in inclined channel, verification of Chazy equation and determination of Chazy Coefficient and Mannings Friction Factor.
Calibration of sharp crested, thin plate overshot weirs. Friction factor and roughened channel bed studies.
Determination of Hydraulic Mean Depth for the flow channel.
Study of flow over triangular hump section, plotting of Specific energy - Depth relationships, comparison of theoretical and experimental values of critical height.
Study of flow under a sluice gate (undershot weir) with application of Specific Energy and Momentum Functions.
Flow straighteners and guide vanes are used. A choice of between one and three flow pumps can be ordered to provide maximum flow rates between 0.3 and 0.8m/s at maximum operating depths. Higher flow rates can be achieved with a smaller depth of water. 300 x 450 mm flow channel (Advanced flow channels) is designed in a modular way to allow different configurations to be purchased against the current and future needs of the user. The inlet chamber has been designed from experience with cavitation tunnels to provide a relatively stable flow. The basic channel is manufactured in 5m sections such that a length of up to 20m can be purchased. The walls of the channel are made from plexiglass (with toughened glass options), the base of the channel is formed from aluminium (with a stainless steel option), and the frame from a coated mild steel fabrication.
Experimental Capability:
Depending on the options purchased, experiments include:
Use and performance of weirs, dams and other hydro structures
Sedimentation transport and settlement
Hull resistance tests and performance
Tidal turbine power measurement
Flow related experiments in open channels
Wind and wave effects on structures.
Structural Specifications:
Diagram in the front panel with similar distribution to the elements in the real unit.
Quick connections for adaptation to feed hydraulics source.
Stainless structure.
Screws, nuts, plates and all the metallic elements in stainless steel.
The apparatus consists of an open channel of rectangular cross section supported at its inlet end by a reservoir tank, and at the outlet end by a frame. A number of test models are provided along with an ink injector to allow streamlines to be observed. This Flow Channel provides a low cost experiment with an easy to set up and use operation. The nominal dimensions of the channel are 20 mm x 150 mm x 650 mm long. The channel walls are made from clear acrylic plastic so that full visibility of the flow characteristics can be achieved.
Experimental Capability:
Study of flow over triangular hump section, demonstration of approximate Specific energy - Depthâ„¢ relationships, comparison of theoretical and experimental values of critical height
Study of flow with variable head inlet and variable head outlet using the adjustable outlet orifice
Visualisation of flow around objects through the injection of ink into the flow
Study of flow under a sluice gate (undershot weir).
Tilting Flow Channel is done by dropping a particle into a vertical liquid column and timing its fall between two points. Various sizes and density of particles are supplied including stream lined shaped objects. The Tilting Flow Channel apparatus is designed to study the drag of a particle in a liquid under various Reynold numbers. A guide at the top of the tube is provided to minimize disturbance to the liquid. A fluorescent tube light at the back of the liquid tube allows clear observation of the particle fall. Valves at the bottom of the tubes provide a mean for particle removal with minimum loss of the liquid.
Experiments:
Effect of boundary layer separation on motion of sphere.
Effect of particle shape on rate of fall and drag coefficient.
Measurement of drag coefficients of sphere under various Reynold numbers.
Exploration of dynamic similarity.
The channel is of a rectangular cross-section supported by steel frame. The channel sides are made of clear acrylic with tilting controlled by a manual screw jack. Sediment Flow Channel is a self contained bench top open channel for studying bed forms with change in flow and slope as well as flow phenomena without sediment. A stainless steel head tank with a stilling baffle provides a smooth flow. A fine strainer is provided in the storage tank to trap the sand sediment. The water is discharged from the channel via a built in rectangular weir to the storage tank.
Experiments:
Flow over fixed gravel bed.
Fixed smooth bed flow.
Local scour.
Mechanics of sediment transport.
Bed form hysteresis.
Flow over mobile sand bed.
Flow structures.
Depositionary features and fancies.
Computational work.
The channel is totally transparent so it allows an optimum visualization of the hydraulic flow. The purpose is to study the flow behavior in open channels and closed pipes, by realizing some experiments in both conditions. These points are connected to the 6 tubes manometer. By floodgates, it is possible to increase water volume in the inlet or outlet tanks. In order to carry out experiments in a closed chamber, the module includes a cover for hermetically seal. Pitot tubes are arranged along the whole length of channel, so it allows measuring the working pressure in 6 points. The equipment can be used stand alone or in conjunction
Open channel:
1. Study of water flows through open channels identifying variables like:
Speed at different points of the cross-sectional area.
Water height
2. Study of constant water flow, gradually varied flow and behavior of surface profiles.
3. Study and utilization of thin edged weir for flow measurements.
Rectangular weir without lateral contraction.
4. Study and utilization of broad crested weir for flow measurements.
Rectangular weir.
5. Analysis and study of discharge under a gate.
Vertical weir
6. Study of jump spillway
The Flow Channel made up of a clear acrylic working section of large depth to width ratio incorporating undershot and overshot weirs at the inlet and discharge ends respectively.
Models supplied with the channel include broad and sharp crested weirs, large & small diameter cylinders and symmetrical & asymmetrical aerofoils which, in conjunction with the inlet and discharge weirs, permit a varied range of open channel and flow visualisation demonstrations.
A dye injection system incorporated at the inlet to the channel permits flow visualisation in conjunction with a graticule on the rear face of the channel.
Water is fed to the streamlined channel entry via a stilling tank to reduce turbulence. Water discharging from the channel is collected in the volumetric tank of the Hydraulics Bench and returned to the sump for recirculation.
