It is widely used in the water, chemical, oil, and gas industries. A venturi meter or venturi flow meter is a device used to measure the velocity, or flow rate, of fluid flowing through a pipeline. The venturi meter is connected to a pipe at two points as shown in the fig. It is a cheaper device as compared to venturimeter.
Bernoullis principle and the equation of continuity. In this post, the effect of venturi meter and hole plate on the flow of liquid will be disked and complete. The manometer tubes 1 and 2 corresponded to the venturi meter. This physics video tutorial provides a basic introduction into the venturi meter and how it works. The coefficient of discharge cd for the venturi meter was greater than that for the orifice meter. In venturi tubes, pressure loss is low and viscosity effect is high. Figure 2 shows an orifice meter with the variable position of vena contracta with respect to the orifice plate. When the fluid used to pass through the venturi meter there is no difference in inlet but at the throat, the velocity is used to increased and there is a decrease in pressure this is due to decreasing crosssectional area from inlet to throat. Venturi in 1797 but this principle comes into consideration with the help of c. The principle of the venturimeter was first demonstrated in 1797 by italian physicist g. The flow measurement apparatus consists of a water loop as shown above figure.
In case of lossofsignal or erratic output, check taps and impulse piping to secondary instrumentation for blockage or debris. A venturi meter is an invasive, full bore flow measurement device that employs a combination of the conservation of mass and energy to determine the flowrate of internal flows in within pipes. The venturi meter is a flow meter that used where highpressure recovery is required. By employing the continuity equation and bernoullis principle, the volumetric flow rate through the orifice meter can be calculated as described previously for venturi meter. When a venture meter is placed in a pipe carrying the fluid whose flow rate is to be measured, a pressure drop occurs between the entrance and throat of the venturimeter.
Jun 05, 2018 the principle of venture meter is firstly developed by g. Venturi in 1797 but it is first considered with the. Venturi 17461822, but the principle was first applied by c. It is invented by american engineer clemans herchel and named by the italian physicist giovanni venturi. Venturimeter is the most widely used device to measure the discharge through the pipe. In his letter, herschel says he tested a oneinch venturi meter, under 210 ft. The corresponding velocity of fluid are v 1 and v 2. Venturi tubes work on the principle of differential pressure measurement. The venturi meters provided on this project were designed and manufactured specifically for this project. Venturi meter is a device or component which is used for measuring the rate of flow of liquid. The fluid whose flow rate is to be measured enters the entry section of the venturi meter with a pressure p1.
This pressure drop is measured using a differential pressure sensor and when calibrated this pressure drop becomes a measure of flow rate. The venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section or choke of a pipe. A schematic of the venturi meter is shown on the diagram at the end of the procedure. If the velocity at any point decreases, the pressure at that point increases due to the conservation of the kinetic energy into pressure energy. A mechanism which regulates volume flow rate of liquid was attached to venturi meter to generate several trials required to establish accuracy of setup in demonstrating bernoullis principle. By measuring the change in pressure, the flow rate can be determined, as in various flow measurement devices such as venturi meters, venturi nozzles and orifice plates main features of venturi meter. Venturi to study the principles of venturi meter and to determine its coefficient cd by comparing the measure flow rate with the ideal flow rate. Orifice meter, venturimeter, pitot tube fall under the first category, while rotameter is of. As the liquid flows through the pipeline, the device measures the pressure of liquid before it enters the venturi tube and as it exist the.
The only difference is that equation is analyzed from the inlet to the throat of the venturi. So in this article, we will talk about venturimeter, its advantages, and disadvantages and the working principle. Venturimeter working principle chemical engineering world. The venturi meter constricts the flow using a herschel venturi tube. Venturimeter is an instrument used to measure the speed and flow rate or discharge of liquids through a pipe. The venturimeter working priciple is based on bernoullis theorem. By measuring the pressure differences the discharge can. Venturi meter problems, bernollis principle, equation of. Principle, derivation, applications, advantages, and disadvantages with pdf.
There is no parts list and there is no recommended stocking level. When a venture meter is placed in apipe carrying the fluid whose flow rate is to be measured, a pressure drop occurs between. The apparatus consists of a flow bench from where water can flow to the venture meter. Venturimeter is a key instrument in the mechanical engineering field, especially in fluid mechanics to measure the flow rate of fluids inside a pipe. Venturi tubes are more expensive to construct than simple orifice plates, and both function on the same basic principle. The area of cross sections of pipe at ends where the venturi meter has been connected are a 1 and a 2 respectively. Spink, 1975 9th edition, published by the foxboro company. Pdf flow through a venturi meter orifice rotameter.
Subject fluid mechanicstopic module 4 venturi meter lecture 28faculty venugopal sharmagate academy plus is an effort to initiate free online. Feb 07, 2015 venturimeter are used to measure the velocity of flow of fluids in a pipe. Venturi meter for normal liquids venturi meters for wet gases venturi material all standard materials available tap connections two. Apr 26, 2015 6 working principle venturi meter works under the principle of bernoullis equation and continuity equation. The equation for venturi meter is obtained by applying bernoulli equation and equation of continuity assuming an incompressible flow of fluids through manometer. Venturi tubes are often used in processes where permanent pressure loss is not tolerable and where maximum accuracy is needed in case of highly viscous liquids. Venturi flow meter installation and operation manual. They consist of short length of pipe shaped like vena contracta, or the portion with the least cross sectional area, which fits into a normal pipeline. Venturi meter1 water supply flow meter stop watch calculator b. Inside the flow bench, a tank is connected to one end of a lever arm. Its a device used to measure the velocity of a fluid in. A venturi meter is an invasive, full bore flow measurement device that employs a combination of the conservation of mass and energy to determine the flowrate. Typically a welldesigned meter with a parallelsided throat has a value of about 0.
Herschel 18421930 in 1887, to develop the device in its present form for measuring the discharge or the rate of flow of fluid through pipes 1. I am now satisfied that here is a new and pregnant principle to be applied to the art of gauging fluids, inclusive of fluids such as compressed air, illuminating or fuel gases, steam, etc. The principle of venture meter is firstly developed by g. Venturimeter are used to measure the velocity of flow of fluids in a pipe. It is a free resource site for mechanical engineering asp. There is a limitation that the diameter which is around 80mm or less than 80 mm can not use venturi meter. Understand the venturi meter is a measuring or also considered as a meter device that is usually used to measure the flow of a fluid in the pipe. It basically works on the principle of bernoullis theorem. Accurate measurement of flow rate of liquids and gases is an essential requirement for. The principle design consists of a venturi meter is to introduce a constriction into a pipe and measure the drop in pressure of fluid in the pipe of original diameter and that in the. The purpose of the experiment is to familiarize oneself with the functionality and readings of a monometer using a venturi meter to flow air through. A venturi meter may also be used to increase the velocity of any type fluid in a pipe at any particular point. Venturi tube resource learn about, share and discuss. In simplest form, the pitot tube consists of a glass tube, bent at right.
Venturimeter engineering explained engineeringclicks. Summary is a representation of pressure and velocity in a fluid 1. In inviscid fluid dynamics, an incompressible fluids velocity must increase as it passes through a constriction in accord with the principle of mass continuity, while. Venturimeter principle, construction and working with diagram. The apparatus for this experiment contained an orifice meter and plate, a venturi flow meter, a rotameter, a weighing bucket with a scale, a stopwatch, and manometers that corresponded to the different meters used. The arrangement of orifice meter is much economical than the use of the venturi meter, but as seen in this experiment the venturi meter provide more accurate results that the orifice meter, so the choice of which to use in a specified laboratory depends on the financial ability of the organization occupying the device and on the accuracy needed. Inlet diameter d 1 velocity v 1 area of crosssection s 1 throat diameter d 2 velocity v 2 area of crosssection s 2 flowrate q. At the end of the seassion, student will be able to. The obstruction caused to the flow of liquid at the throat of the venturi produces a local pressure drop in the. Venturi meter has a limitation and that is its low reynolds number of 150,000. The principle of venturimeter is that when a fluid flows through the venturimeter, it accelerates in the convergent section and decelerates in the divergent section, resulting in a drop in the static pressure followed by a pressure recovery in the flow direction.
Fluid mechanics module 4 venturi meter lecture 28 youtube. The venturi meter principle works on bernoulli equation like velocity is increase if the pressure decreases. As the fluid from the entry section of venturi meter flows into the converging section, its pressure keeps on reducing and attains a minimum value p2 when it enters the throat. It is a free resource site for mechanical engineering aspirants. This also work on the same principle as that of venturimeter.
Venturi meter is used to measure the flow rate of fluid via a pipe. Laboratory experiment on venturi meter and orifice meter. Pdf this study intended to concretize bernoullis principle through a lowcost venturi meter designed and constructed by the researchers find, read and cite all the research you. A venturi is a convergingdiverging nozzle of circular crosssection. Pdf water flow venturi meter akorede oyindamola academia.
Such a device is called a venturi meter since it relies on the venturi effect. It consists of flat circular plate which has a circular hole, in concentric with the pipe. In the venturi meter, the pressure energy is converted to kinetic energy. Operating principles and theory for venturi meter the basic equation for the venturi meter is obtained by writing the bernoulli equation for incompressible fluids between the two pressure stations at f and i. It works on the basic principle of bernoullis equation. This equation highlights the energy applied to a fluid flow where there is no friction, and pressure is static 2. Venturi tubes are appropriate for clean, dirty and viscous liquid and few slurry services as well. It then returns to the original dimensions of the pipe by a gently diverging diffuser section. Definition, parts, working, derivation, applications. The venturi effect is named after its discoverer, giovanni battista venturi.
Therefore, equation 4 will be changed to equation 9 and since the two points are at the same elevation cancels. Venturi meter a venturi can also be liquid flow rate measurement venturi flume flowbox liquid flow rate measurement venturi orifice and venturi meter prelab pdf free download april 4th, 2019 objectives the main objective of the experiment is to determine discharge coefficient for both the venturi meter and the orifice meter at varying va rying. Find the enterprise measurement factor and venture meter opening according to michael. A venturi is a convergingdiverging nozzle of circular. Venturi meter is a device in which pressure energy is converted into kinetic energy and it is used for measuring the rate of flow of liquid through pipes. Venturimeter is an instrument which is used to measure average velocity of a flowing fluid or flow rate of a flowing fluid. Venturi meter for normal liquids venturi meters for wet gases venturi material all standard materials available. Variable area flow meters rotameters, turbine flow meter, target flow meters etc. Venturi meter the venturi meter is a device for measuring discharge in a pipe. The critical dimensions of the classical venturi tube. The pressure along the meter is obtained using the 11 pressure taps at the locations shown on the diagram.
Airfoil and hydrofoil designs to lift and steer air and water vessels airplanes, ships and submarines are derived from applications of the bernouoli principle and the venturi effect, as are the instruments that. The principle is that when cross sectional area of the flow is reduced then a pressure difference is created between the different areas of flow which helps in measuring the difference in. The inlet diameter equals d 26 mm and the throat diameter d 16 mm. It consists of a rapidly converging section which increases the velocity of flow and hence reduces the pressure. A picture showing the different flow meters is in figure 1. Pdf flow measurement and control system in oil gas industry. In principle the constriction could be an abrupt change of crosssection, but it is better to use a more gradual constriction and an even more gradual return to the full flow area following the constriction. Pressure recovery for venturi tubes is a lot better as compared to the orifice plates. Procedure let us first define the venturi meter and the way it works in order to proceed in the experiment.
The water flow rate can be adjusted using the valves on the hydraulics bench. Venturi principle definition of venturi principle by. The venturi principle states that the pressure drop distal to a restriction can be nearly restored to the prerestriction pressure if there is a dilatation of the passage immediately distal to the stenosis, with an. Download pdf for free principle and working of venturimeter example a venturimeter is a device used for measuring the rate of a flow of a fluid flowing through a pipe. Introductionthe aim of the investigation is to experimentally determine the coefficient of discharge of a specific venturi meter and compare the result to previously obtained empirical results. Industrial designs, operating principles, performance, and applications. Furthermore, this experiment will compare in addition, this. The bernoulli principle and its corollary, the venturi effect, are essential to aerodynamic as well as hydrodynamic design concepts.
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