What does coefficient of discharge of a notch indicate?
The rectangular weir (notch) is a common device used to regulate and measure discharge in irrigation projects. The values of the discharge coefficient increase with increases in the values of the upstream water depth.
How do you calculate discharge using rectangular notch?
The formula for Discharge in Rectangular Notch is – (Where B = width of notch, and H = height of liquid above the sill of the notch)
- 3 2 C d L 2 g H 3 / 2.
- 3 2 C v L 2 g H 3 / 2.
- 3 2 C c L 2 g H 3 / 2.
- 2 3 C d L 2 g H 3 / 2.
How is discharge calculated using V notch?
V notch weirs really are just that – a thin plate weir with a ‘V’ notch cut into it. The weir is placed to obstruct open channel flow and allow water to flow over the notch. This enables us to accurately measure the flow, by measuring the head upstream of the V notch.
How do you calculate the coefficient of discharge?
The discharge coefficient of an orifice or nozzle is defined as the ratio of the actual to theoretical flow rate:
- Cd=Measured Flow RateTheoretical Flow Rate (1)
- η=σΔp12ρ¯V2 (6)
- ξ=σΔp¯Δp (7)
What is the range of coefficient of discharge?
The orifice discharge coefficients are in the range of 0.6-0.9 and are affected by the fluid viscosity and the size of the vena contracta in the orifice.
What does a high coefficient of discharge mean?
Coefficient of discharge is stated as the ratio between the actual flow discharge and theoretical flow discharge. In nozzle flow measurement, the efficiency of Cd is higher when compared to the flow measurement at the orifice. …
What are the factors that affect the coefficient of discharge?
Discharge Coefficient
- Friction.
- Electric Inductors.
- Viscosity.
- Nozzle.
- Reynolds’ Number.
- Mass Flowrate.
Can coefficient of discharge be greater than 1?
Plug in a coefficient for energy losses through turbulence and you have your formula. But you can see indeed that your coefficient can never be greater than one, because that would mean that you end up with more energy than you started with.
What is the importance of coefficient of discharge?
The discharge coefficient is a dimensionless number used to characterise the flow and pressure loss behaviour of nozzles and orifices in fluid systems. Orifices and nozzles are typically used to deliberately reduce pressure, restrict flow or to measure flow rate.
Is coefficient of discharge constant?
Unlike the flow coefficient, discharge coefficient is dimensionless and almost constant value for any diameter of a single model. For the same high of fluid in the reservoir, higher is the discharge coefficient, higher is the flow rate, therefore the reservoir can be voided at shorter time.
What is discharge formula?
Discharge = V x D x W If length is measured in feet and time in seconds, Discharge has units of feet3/sec or cubic feet per second (cfs). Depth times Width gives the cross-sectional area. The shape of the channel is important because of the reduction in velocity due to friction along the channel margins.
What is coefficient of discharge of orifice meter?
The discharge coefficient – cd – varies considerably with changes in area ratio and the Reynolds number. A discharge coefficient cd = 0.60 may be taken as standard, but the value varies noticeably at low values of the Reynolds number. For an area ratio of 0.5 the head loss is about 70 – 75% of the orifice differential.
Why coefficient of discharge is high in Venturimeter?
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 …
What is the coefficient of discharge for a Venturi meter?
The discharge coefficient of a Venturi meter is typically 0.985, but may be even higher if the convergent section is machined.
What is the principle of orifice meter?
Orifice meter: is a device used for measuring the rate of flow of a fluid flowing through a pipe. It is a cheaper device as compared to venturimeter. This also work on the same principle as that of venturimeter. It consists of flat circular plate which has a circular hole, in concentric with the pipe.
Who is the formula of orifice Metre?
The working of the orifice meter is based on the principle of Bernoulli’s equation. As you can see in the diagram there is a pipe in which fluid is passing from one side to another side that is an inlet to outlet. The manometer is attached hereto measure the pressure differences between two-point.
Why orifice is needed in our daily life?
Applications of Orifice Meter It is used to measure the flow rate of fluids in their single state (i.e. gaseous state or liquid state). It can also be used to measure the flow rate of fluids in a mixed state (both gaseous and liquid states) such as, wet steam, or natural gas with water.
What is the purpose of orifice?
An orifice plate is a device used for measuring flow rate, for reducing pressure or for restricting flow (in the latter two cases it is often called a restriction plate ).