How do you find the coefficient of discharge in V notch?
How do you find the coefficient of discharge in V notch?
Exp-5 V-NOTCH
- AIM : To determine the coefficient of discharge of v – notch.
- APPARATUS : V-Notch equipment, Bucket, Inclined manometer, stop-watch.
- PROCEDURE :
- GRAPHS : Q = CD 8/15 tanΘ/2 √2g H5/2 Q = K H5/3 ; K = CD 8/15 tanΘ/2 √2g.
- RESULT : The value of discharge coefficient of v-notch obtained from,
- OBSERVATION TABLE :
What is coefficient of discharge of a notch?
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 is coefficient of discharge measured for triangular notch?
The coefficients of discharge are determined by measuring the height of the water surface above the notch base and the corresponding flow rate. The general features of the flow can be determined by direct observation.
Why is V notch used for small discharge?
The basic principle is that discharge is directly related to the water depth above the crotch (bottom) of the V; this distance is called head (h). The V-notch design causes small changes in discharge to have a large change in depth allowing more accurate head measurement than with a rectangular weir.
How do you find 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 significance of coefficient of discharge?
An important element in this process is the discharge coefficient, which is defined as: “In a nozzle or other constriction, the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an iden- tical working fluid from the same initial conditions to the same exit pressure” …
What is the purpose of V notch?
What is a V notch weir? 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 for a nozzle?
In a nozzle or other constriction, the discharge coefficient (also known as coefficient of discharge or efflux coefficient) is the ratio of the actual discharge to the theoretical discharge, i.e., the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an identical …
Is the coefficient of discharge a constant for all notches Why?
The coefficient of discharge for both notches is different due to the height of the depth water level. This is due to the space for the water to flow through the notch. For rectangular notch, the space of water it is constant for every depth.
What is V notch method?
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.
Is discharge coefficient a 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.
Can coefficient of discharge be greater than 1?
In practice, the discharge coefficient cannot be greater than one. This is a fact. The error may be in compensating the values of the variables in the equation. Verifies units, values, and homogeneity of area values.
Why does V notch have a higher discharge coefficient?
The graph Log Q against Log H for rectangular notch was plotted in straight line. Then, the relationship for graph head over weir against coefficient discharge is directly proportional. The coefficients discharge increase when the volume flow rate increased.
How to calculate the free flow of a V notch?
For V-notches between 25 and 100 degrees, the Kindsvater-Shen relationship can be applied to calculate the free-flow discharge equation (Kulin and Compton). The equation is as follows: The effective discharge coefficient, C e, and the head correction factor, k h, can be obtained from the charts below (BSI):
When do you need to calculate discharge equations for V-notch weirs?
Sometime there is a need to correct for a weir plate cut at an incorrect angle. While other times the flows of a particular site don’t match up well with the flow characteristics of the standard sizes of V-notch weirs. Regardless of the reason, there is a need to be able to calculate discharge equations for intermediate V-notches.
What’s the difference between rectangular notch and V notch?
The coefficients discharge increase when the volume flow rate increased. The value of discharge coefficient for rectangular notch was 2.26 while V-notch was 4.66.V-notch has high coefficients discharge compared to rectangular notch. V-notch gives more accurate results for low discharge coefficient compared to rectangular notch.