Head Given Discharge Over Cipolletti Weir Calculator

Cipolletti Weir Formula:

\[ H = \left( \frac{Q}{1.86 \times L} \right)^{2/3} \]

Height of Water above Crest of Weir (H):

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1. What is the Cipolletti Weir Formula?

The Cipolletti weir formula calculates the height of water above the crest of a weir based on the discharge rate and the length of the weir crest. This formula is commonly used in hydraulic engineering for flow measurement in open channels.

2. How Does the Calculator Work?

The calculator uses the Cipolletti weir formula:

\[ H = \left( \frac{Q}{1.86 \times L} \right)^{2/3} \]

Where:

\( H \) — Height of Water above Crest of Weir (m)
\( Q \) — Discharge by Cipolletti (m³/s)
\( L \) — Length of Weir Crest (m)
1.86 — Cipolletti weir coefficient

Explanation: The formula calculates the water height above the weir crest based on the discharge rate and weir length, using the standard Cipolletti coefficient of 1.86.

3. Importance of Head Calculation

Details: Accurate head calculation is crucial for designing weirs, measuring flow rates in open channels, and ensuring proper hydraulic system performance in irrigation, water supply, and drainage systems.

4. Using the Calculator

Tips: Enter discharge in cubic meters per second (m³/s) and weir crest length in meters (m). Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a Cipolletti weir?
A: A Cipolletti weir is a type of sharp-crested weir with trapezoidal shape, specifically designed to compensate for end contractions and provide more accurate flow measurements.

Q2: When is the Cipolletti formula most accurate?
A: The formula is most accurate for free-flow conditions with proper weir installation, adequate approach velocity, and when the weir is not submerged.

Q3: What are typical applications of Cipolletti weirs?
A: Commonly used in irrigation channels, wastewater treatment plants, and hydraulic laboratories for flow measurement and control.

Q4: Are there limitations to this formula?
A: The formula assumes ideal conditions and may require adjustments for submerged weirs, very low or very high flow rates, or non-standard weir installations.

Q5: How does weir crest length affect the calculation?
A: Longer weir crests result in lower water heights for the same discharge, while shorter crests produce higher water levels above the weir.