May 09, 2010 this video acquired at the marburg university flume shows part of a labscale alluvial fan. A venturi flume is a criticalflow open flume with a constricted flow which causes a drop in the hydraulic grade line, creating a critical depth. Experiments were conducted by filling an inclined flume with loose sand. Explain the process used to calibrate appropriate equations to measure open. I adjusted the position of the hydraulic jump by adjusting the amount of closure of slvice gate. When flow out of the parshall flume is returning to a channel or pipe, the epa recommends that the channel be straight and unobstructed for 520 throat widths although flow spilling freely off the end of the flume can eliminate this requirement. I then measured the depth of the bed of flume by using a point gauge. Civil engineering lab ii group 3 hydraulics 1 hd 1. The rainfallinduced slope failure is the major geohazard all over the world including malaysia. Sieve lobe dominated fan a flume experiment youtube. Number of studies done already to investigate the process of slope failure, however the parameters that control the initiation of flowslide type of failure is still lacking. Flow rate is calculated from measured depth of flow if an equation relating this depth with flow rate is known.
Table 1 shows the parameters of each experiment, averaged over the flume width, the flume length reduced by the bed form adaptation length, and over the period in which the bed form dimensions, the bed roughness, and the sediment. View flume experiments research papers on academia. Flume experiments on the transport of a coarse sand. Notable factors in comparing application of the venturi solution to a pipe meter with using the venturi solution on a longthroated flume are the magnitude of head differential observed as flow moves from the approach section, then is accelerated through the constricted throat sections. When studying hydraulics, the fundamental concepts of energy and momentum are sometimes difficult to grasp, particularly where free surface flow is concerned. A sedimentrecirculating flume see chapter 8 works the same way, and in that sense is a good model for fluvial sediment transport. Figure shows the plan and elevation of a venturiflume. Flume simulation of recirculating flow and sedimentation. Table 1 shows the parameters of each experiment, averaged over the flume width, the flume length reduced by the bed form adaptation length, and over the period in which the bed form dimensions, the bed roughness, and the sediment transport rate and composition varied about a stable mean. It is used in flow measurement of very large flow rates, usually given in millions of cubic units. The unit is designed for installation in the modular flow channel hm162. This constriction results in an increase of flow depth above the flume. The experimental section is 2,5m long and can be increased to 5m with the extension element hm 160.
Both are often violated in nature and these violations may fundamentally change the expected relationship between shear stress and erosion rate. Furthermore, it is hoped that the construction of larger sizes of venturi flumes than were tested in the laboratory will be encouraged thereby. Department of the interior bureau of reclamation yuma area office yuma, az may 2009. Flume width and water depth effects in sedimenttransport experiments by garnett p. Charateristics of flow through a venturi flume objective the purpose of this experiment is to determine the relationship between upstream head and flow rate for water flowing through a venture flume and determine the discharge coefficient and observe the flow patterns. Simplified flow corrections for parshall flumes under.
Therefore, to insure adequate time for conditions of dynamic equilibrium to develop with no associated changes in pool dimensions, each flume experiment was conducted for a total of 4 h. Experiments school of engineering the university of. Flow through venturi meter background and theory introduction flow meters are used in the industry to measure the volumetric flow rate of fluids. The parshall flume is an economical and accurate way of measuring the flow of water in open channels and nonfull pipes. A qh related ultrasonic volume measurement type nivumaster has been installed. The crosssection of the experimental section is 86x300mm. In experiment t7, the flow velocity was increased, which resulted in higher dunes and a lowering of the coarse layer. Parshall flumes are commonly used in irrigation systems, storm water systems, and sewer systems in order to measure the flow rate. Geometric adjustment of pools to changes in slope and.
The unit is designed for installation in the modular. The headdischarge relationship of such measurement devices can be determined following the critical flow theory, but this approach is only valid if the length of the throat is sufficiently long. To transition the flow out of a parshall flume, wing walls should be used. The experimental flume hm 160 has a closed water circuit. The pressure drop associated with each meter is measured directly from the. In experiment t5, which started with a fully mixed bed, small barchan. The venturi effect is achieved by way of a horizontal constriction of the. Venturiflume it is a devise used to measure the discharge in an open channel. The dissolved oxygen content in surface waters is a main indicator of the quality of that water for human use as well as use by the aquatic plant and animal life. Video of an experimental river flume in the basement of padnos hall of science. Tilting flume consists of a channel of size as in specifications. The flume was originally developed to measure surface waters, water rights apportionment, and irrigation flows, but its use has expended to include measuring the flow of sewage both in pipe and treatment plants, industrial discharges, dam seepage, and other applications. Due to solid matter contained in sewage, the discharge in sewer technology is usually measured with a venturi flume. Venturi flumes are used in openchannels to determine the discharge by the measurement of a water level.
Rectangular venturi flume the original idea was to invent a device which would replace the ordi nary rating flume, such as is used in irrigation canals. The note that although the intake point for stilling wells measuring hb is below the floor of the converging section, the zero elevation for both ha and hb is the converging floor. Hd 1 r1 civil engineering lab iigroup 3 hydraulics 1 hd 1. It can be identified by both a section that has a contraction in the width of the flume as well as a dip in the elevation of the bottom of the flume. Attention was paid to keep the grainsize distribution of the sediment the same for all experiments. Venturiflume 1 venturiflume it is a devise used to measure the discharge in an open channel. Preliminary flume runs of pool shape through time indicated that pool geometry scoured to its full extent and began to stabilize after. The experiments in the ciem wave flume consist of three separate measurement campaigns, each of 8 week duration. Venturi flume is a very popular flow measuring device. Parshall flume sizes are designated by the throat width, w, and dimensions are available for flumes from the 1in size for free flow of 0. The cambridge coastal research unit ccru, in collaboration with deltares nl, the university of hamburg germany, the netherlands centre for estuarine and marine ecology niooceme, nl and the university of hannover germany has obtained funding under the eu hydralab iv call to acquire fundamental knowledge on the wave dissipation process. Williams abstract this paper reports 177 flume experiments made in channels of different widths and water depths, the purpose being to find how the flume width and flow depth influence experimental results. This video acquired at the marburg university flume shows part of a labscale alluvial fan.
It was thought that the flume might be converted into a selfcontained measuring device by placing a restricted section in the flume, which would cause a loss of. Experimental setup consists of a flume of 6 m long x 4 m wide and 1. A particularly attractive version of such a device is a standingwave flume, as this enables determination of liquid discharge by onepoint. Grant2, yoshiharu ishikawa 3 and hiroshi ikeda4 1department of geosciences, oregon state university corvallis, or 97331, u. Differential pressure type flow meters head flow metersmeasure flow rate by introducing a constriction in the flow. A flume experiment on wood storage and remobilization in braided river systems. Accuracy of flow rate measurements by flumes is a little lower than offered by sharp crest weirs, but operation much more reliable, and much lower. Lab manual of venturi flume experiment printable 2019 online reading at eliteweb. The bed was carefully saturated with water, the flow was started slowly 15 minutes to prevent bed damage. A flume experiment on wood storage and remobilization in.
Broad crested weirventuriflume almost same procedure the chairman lukongo ngenge. The height change is the difference in height between the upstream and downstream water heights. This calculator finds the flow rate for a parshall flume. At the inlet a flow steadying section is provided so that there will be fewer disturbances at the test section.
The side walls of the experimental section are made of tempered glass, which allows excellent observation of the experiments. Flow measurement with long throated flumes under uncertain. Williams abstract this paper reports 177 flume experiments made in channels of different widths and water depths, the purpose being to find how the flume. Download file pdf lab manual of venturi flume experiment the venturi flume hm162. Differential pressure type flow meters head flow metersmeasure flow rate by introducing a constriction in. Experimental results to date, while incomplete, bear out this inference and suggest a complex interplay among bed topography, sediment size distribution, fluid discharge, and bed slope. Jun 12, 2015 parshall flumes are commonly used in irrigation systems, storm water systems, and sewer systems in order to measure the flow rate. Landslide fluidization process by flume experiments. A venturi meter would normally measure in millimetres, whereas a venturi flume measures in metres. The armfield multi purpose teaching flume has been developed to assist students to overcome this difficulty. The freeflow discharge range and dimensions for parshall flumes are given on figure 8. Experiments school of engineering the university of aberdeen. Jan 14, 20 video of an experimental river flume in the basement of padnos hall of science.
It was thought that the flume might be converted into a selfcontained measuring device by placing a restricted section in the flume, which would cause a. An almost realsize slope model was used to study the generation process of landslide fluidization during torrential rain. The main objectives of this experiment is to obtain. Info free download books lab manual of venturi flume experiment printable 2019 everyone knows that reading lab manual of venturi flume experiment printable 2019 is helpful, because we could get information in the reading materials. Flume experiments on the transport of a coarse sand by garnett p. Then i closed the tail gate to allow water to accumulate and to develop hydraulic jump. Flume experiments for investigation of rainfallinduced slope. Experiment empty flume bed aggradation flow rate, m3s 0. The bed elevation along the flume centerline was measured and recorded before and after each experiment using an ultrasonic limnimeter mounted on a carriage l8 in figure 1. Before each experiment the bed was raked, leveled, and compacted. Ppt venturiflume powerpoint presentation free to view. Tilting flume, heat transfer lab, mass transfer lab.
Parshall flume is located in the throat of the flume, close the junction of the throat and the discharge section. Flume experiments and modelling of flowsedimentvegetation. The ciem wave flume of the maritime engineering laboratory at the catalonia university of technology is 100m long, 3m wide and 5m deep. An experimental investigation of the aeration performance of. Broad crested weirventuriflume almost same procedure. Simulation of seepage from subsurface groundwater level from a distant source using a constant head tank. The sediment leaving the flume was collected and measured over time intervals of 20 or 30 min, enabling the cumulative volume of lateral diffusion and deposition of bed load into the strips to be determined dotted lines, fig. Using the parshall flume flow equations and tables, determine the flow type free flow or submerged flow and discharge for a 36inch flume with an upstream depth, ha of 1. Flume experiments for investigation of rainfallinduced. This flume corresponds to a locally constricted channel normally without a bottom inset to force a transition between sub and supercritical flows. Hydraulic jump experiment laboratory practical manual notes.
In tropical areas different mass movements occur from erosion to flow type of failure, in order to understand the mechanism. The flow is determined using a sudden enlargement, venturi meter, orifice plate, elbow and a rotameter. This work investigates wood dynamics in braided streams through physical modelling in a mobile bed laboratory flume, with the specific objective to characterize wood storage and turnover as a function. A higher dissolved oxygen content supplies better water quality. Starting from 100% coarse sand, the result of adding fine sand causes a dramatical change in transport. Flume experiments with a natural and a trimodal sediment mixture. A venturi flume is a criticalflow open flume with a constricted flow which causes a drop in the hydraulic grade line, creating a critical depth it is used in flow measurement of very large flow rates, usually given in millions of cubic units. Landslide fluidization process by flume experiments request pdf. From now on, this period is called the equilibrium. It is designed in such a way that the velocity at the throat is less than the critical velocity so that no standing wave will occur in the flume. Flow measurement with longthroated flumes under uncertain submergence. Chapter 14 mixedsize sediments introduction 1 in a certain sense, this is the most significant chapter in part 2 of these course notesinasmuch as virtually all natural sediments comprise a range of particle sizes, not just a single size. Hd 1 r1 civil engineering lab iigroup 3 hydraulics 1.
An experimental investigation of the aeration performance. The flow obstruction used in the experiment is a smooth bump located on the flume floor at about 10 m from the flume entrance. In order to maintain the measuring uncertainty as low as possible, an ultrasonic sensor with a very low dead zone type pm3, dead zone 0. The flume experiments were started with a mixed bed, installed at a bed slope that is equal to the water surface slope of the experiments. A particularly attractive version of such a device is a standingwaveflume, as this enables determination of liquid discharge by onepoint.405 78 1200 540 909 314 1232 853 297 96 1420 640 315 799 61 729 1397 125 313 716 51 664 962 846 1522 676 459 971 570 951 1159 923 890 893 504 91 349