In Venturi meter losses are less so coefficient of discharge is higher whereas in orifice meter due to no convergent and divergent cones there are more losses and hence its coefficient of discharge is less.In venturi meter losses are low due to steamline shape of the diffuser and the pressure gradient is not abrupt as in case of orifice meter.
Venturi Meter is a device used for measuring the flow of the fluid.
The calibration curve for an orifice meter will depend on the size of the orifice, the size of the pipe and the pressure loss over the meter. Typical calibration curves have pressure (or head) loss on the vertical (y) axis and flow rate on the horizontal (x) axis.
1.to measure the flow rate of gases and fluids
In case of venturi meter, at the diverging section mach number is less than 1. however in diverging section of a nozzle mach number is greater than 1.
1. It is used for flow measerment with minimum head loss. 2. It is used in industries for flow measerment of chemicals. 3. it is also used in the airoplane for measurment of speed of plane.
The discharge coefficient is near unity and Non-recoverable net head loss is very small.
The orifice plate can easily be changed to accomodate widely different flow rates, whereas the throat diameter of a venturi is fixed, so that its range of flow rates is circumscribed by the practical limits of Dp.The orifice meter has a large permanent loss of pressure because of the presence of eddies on the downstream side of the orifice-plate; the shape of the venturi meter prevents the formation OS these eddies and greatly reduces the permanent loss.The orifice is cheap and easy to install. The venturi meter is expensive, as it must be carefully proportioned and fabricated. A home made orifice is often entirely satisfactory, whereas a venturi meter is practically always purchased from an instrument dealer.On the other hand, the head lost in the orifice for the same conditions as in the venturi is many times greater. The power lost is proportionally greater, and, when an orifice is inserted in a line carrying fluid continuously over long periods of time, the cost of the power may be out of all proportion to the saving in first cost. Orifices are therefore best used for testing purposes or other cases where the power lost is not a factor, as in steam lines.However, in spite of considerations of power loss, orifices are widely used, partly because of their greater flexibility, because installing a new orifice plate with a different opening is a simpler matter. The venturi meter can not be so altered. Venturi meters are used only for permanent installations.It should be noted that for a given pipe diameter and a given diameter of orifice opening or venturi throat, the reading of the venturi meter for a given velocity is to the reading of the orifice as (0.61/0.98)2, or 1:2.58.(i.e. orifice meter will show higher manometer reading for a given velocity than venturi meter).
Venturi Meter is a device used for measuring the flow of the fluid.
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water flow from a tank having a free surface area of 10m2 over a 900 notch.it is found that the time taken to lower the level from 8cm to 7cm above the level of the notch is 43.5sec.determine the coefficient of discharge assuming it remains constant during the period
The orifice meter is used with the orifice flow rate meter and measures things like the flow rate of natural gas. It can measure other things and companies use it for different things also. Some companies give lessons or classes in using the orifice meter.
hitler
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Orifice meter is a flow measuring device used for calculating the pressure drop,flow rate and behaviour of the fluid moving through the pipe.
The calibration curve for an orifice meter will depend on the size of the orifice, the size of the pipe and the pressure loss over the meter. Typical calibration curves have pressure (or head) loss on the vertical (y) axis and flow rate on the horizontal (x) axis.
more accurate
the basic principle on which a Venturimeter works is that by reducing the cross-sectional area of the flow passage, a pressure difference is created and by measuring this pressure difference, discharge through the pipe can be determined. formula to find actual discharge is=amount of fluid collected/time taken it works on the principle of bernoulli"s equation