How is discharge calculated using V notch?
How is discharge calculated using V notch?
V Notch Weir Equation for Notch Angle Other than 90 Degrees of Reclamation, Water Measurement Manual, should be used. That equation is: Q = 4.28 Ce Tan(θ/2)(H + k)5/2, where Q and H are as previously defined, θ is the angle of the v notch, Ce is the effective discharge coefficient, and k is a head correction factor.
Which formula is used to measure the discharge through a triangular notch or weir?
The Equation = Flow Rate in cfs. = Height of the upstream water above the bottom of the weir in feet.
What are the advantages of V notch over rectangular notch?
Answer. Well a V-score gives better exact outcomes when contrasted with rectangular indent. A traingular indent gives more precise outcomes for low releases than a rectangular score. The same triangular score can gauge an extensive variety of streams precisely.
What is calibration of V notch?
As water approaches the notch, its surface becomes curved. Therefore, the head over the notch is to be measured at the upstream of the notch where the effect of curvature is minimum. Also, it should be close to the notch so that the loss of energy between head measuring section and notch is neglegible.
What does coefficient of discharge of a notch indicate?
The results obtained from this research indicate that the relationship between the discharge coefficient and the upstream water depth is a power function. The values of the discharge coefficient increase with increases in the values of the upstream water depth.
Why does the V-notch give more accurate flow measurement?
V-notch gives more accurate results for low discharge coefficientcompared to rectangularnotch. 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 are the advantages of vee notch?
It is used to meter flow of water in the channel, by measuring the head of water over the v notch crest. The v notch weir is especially good for measuring a low flow rate, because the flow area decreases rapidly as the head over the v notch gets small.
What is the use of triangular notch?
The triangular-notch, thin-plate weir is a convenient, inexpensive, and relatively precise flow-measuring instrument. It is frequently used to measure the flow of water in laboratories and in small, natural streams.
What are the advantages of triangular notch?
A triangular notch gives much more accurate results in low discharge conditions, as compared to the conventional rectangular notch. Also, only one reading (the head) is required to calculate the discharge rate, making calculations much easier. However, it cannot handle large volumes of flow rate accurately.
What are the disadvantages of V-notch?
| Advantages | Disadvantages |
|---|---|
| High requirements for the calming of the velocity field | |
| Most frequent errors | |
| low quality of cutting out of the notch, the crest is not sharp (the thicknes is higher than 1 mm ), the vertex of the notch is not smooth | |
| Faulty geometry of weir, wrong horizontal setting, defected crest |
How to calculate the V notch weir discharge?
90º V-Notch Weir Discharge Table Formulas (H in feet):CFS = 2.500 H ft. 2.5GPM = 1122 H ft. 2.5 MGD = 1.616 H ft. Formulas (H in meters):L/S = 1380 H m 2.5M3/HR = 4969 H m 2.5 FEET INCHESMETERS CFS GPM MGD L/S M3/HR
How to calculate the flow rate of a V notch?
That equation is: Q = 4.28 C e Tan (θ/2) (H + k) 5/2, where Q and H are as previously defined, θ is the angle of the v notch, C e is the effective discharge coefficient, and k is a head correction factor. The diagram at the left is a graph of C e as a function of notch angle, θ, and the diagram at the right gives k as a function of θ.
Which is the correct equation for stage discharge?
The standard orifice equation is used for culverts and orifices. h (i) = inlet control head. h (o) = outlet control head. During the calculation process, both inlet and outlet control are evaluated. Under inlet control, the discharge depends on the barrel shape, cross-sectional area of the pipe and inlet edge.
How are V-notch and Cipoletti weirs affected?
Rectangular, V-notch & Cipoletti weirs can be affected by submergence, i.e., when the tailwater rises above the weir’s crest. This will reduce the flow over the weir crest. The equation for the reduction in flow is: