Length of Crest given Discharge for Cipolletti Weir Calculator

Formula Used:

\[ L_w = \frac{3 \times Q_C}{2 \times C_d \times \sqrt{2 \times g} \times S_w^{3/2}} \]

Discharge by Cipolletti (Q_C):

m³/s

Coefficient of Discharge (C_d):

Acceleration due to Gravity (g):

m/s²

Height of Water above Crest of Weir (S_w):

Length of Weir Crest (L_w):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Length of Crest given Discharge for Cipolletti Weir?

The Length of Crest given Discharge for Cipolletti Weir formula calculates the required length of a weir crest to achieve a specific discharge rate, taking into account the coefficient of discharge, gravitational acceleration, and water height above the weir crest.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ L_w = \frac{3 \times Q_C}{2 \times C_d \times \sqrt{2 \times g} \times S_w^{3/2}} \]

Where:

\( L_w \) — Length of Weir Crest (m)
\( Q_C \) — Discharge by Cipolletti (m³/s)
\( C_d \) — Coefficient of Discharge
\( g \) — Acceleration due to Gravity (m/s²)
\( S_w \) — Height of Water above Crest of Weir (m)

Explanation: This formula calculates the required length of a weir crest based on the discharge rate and other hydraulic parameters.

3. Importance of Weir Crest Length Calculation

Details: Accurate calculation of weir crest length is essential for proper hydraulic design, flow measurement, and water management in irrigation systems, dams, and other hydraulic structures.

4. Using the Calculator

Tips: Enter discharge in m³/s, coefficient of discharge, gravitational acceleration in m/s² (default is 9.8), and water height above crest in meters. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a Cipolletti weir?
A: A Cipolletti weir is a type of sharp-crested weir with a trapezoidal shape, designed to measure flow rates in open channels.

Q2: What is the typical range for coefficient of discharge?
A: The coefficient of discharge for Cipolletti weirs typically ranges from 0.60 to 0.75, depending on the specific design and flow conditions.

Q3: Why is gravitational acceleration important in this calculation?
A: Gravitational acceleration affects the velocity of water flowing over the weir, which directly impacts the discharge rate and thus the required crest length.

Q4: What are the limitations of this formula?
A: This formula assumes ideal flow conditions and may need adjustment for real-world factors like viscosity, surface tension, and approach velocity.

Q5: Can this calculator be used for other types of weirs?
A: No, this specific formula is designed for Cipolletti weirs. Other weir types have different discharge equations and coefficients.