1. What is the Cipolletti Weir Formula?

The Cipolletti weir formula calculates the discharge rate for a trapezoidal weir when velocity is considered. It accounts for both the still water head and the velocity head to provide a more accurate measurement of flow rate.

2. How Does the Calculator Work?

The calculator uses the Cipolletti formula:

Where:

• \( Q_C \) — Discharge by Cipolletti (m³/s)
• \( L_w \) — Length of Weir Crest (m)
• \( H_{Stillwater} \) — Still Water Head (m)
• \( H_V \) — Velocity Head (m)

Explanation: The formula calculates the difference between the still water head and velocity head raised to the power of 3/2, multiplied by the weir length and the constant 1.86.

3. Importance of Discharge Calculation

Details: Accurate discharge calculation is crucial for water resource management, irrigation system design, flood control, and hydraulic engineering projects.

4. Using the Calculator

Tips: Enter length of weir crest in meters, still water head in meters, and velocity head in meters. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a Cipolletti weir?
A: A Cipolletti weir is a trapezoidal weir with side slopes of 1:4 (horizontal:vertical), designed to compensate for end contractions.

Q2: When should velocity head be considered?
A: Velocity head should be considered when the approach velocity is significant, typically when the approach channel has noticeable flow velocity.

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

Q4: What are the limitations of this formula?
A: The formula assumes specific weir geometry and may not be accurate for very low heads or when the weir is not properly installed.

Q5: How does this differ from other weir formulas?
A: The Cipolletti formula specifically accounts for the trapezoidal shape and includes compensation for end contractions, unlike rectangular weir formulas.