Actual Discharge Over Broad Crested Weir Calculator

Formula Used:

\[ Q_a = C_d \times L_w \times h_c \times \sqrt{(2 \times g) \times (H - h_c)} \]

Coefficient of Discharge (C_d):

Length of Weir Crest (L_w):

Critical Depth of Weir (h_c):

Acceleration due to Gravity (g):

m/s²

Total Head (H):

Actual Discharge over Broad Crested Weir (Q_a):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Actual Discharge Over Broad Crested Weir?

Actual Discharge over Broad Crested Weir is a measure of the actual quantity of any fluid flow over unit time. The quantity may be either volume or mass. It is calculated using the broad crested weir formula which accounts for various hydraulic parameters.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q_a = C_d \times L_w \times h_c \times \sqrt{(2 \times g) \times (H - h_c)} \]

Where:

\( Q_a \) — Actual Discharge over Broad Crested Weir (m³/s)
\( C_d \) — Coefficient of Discharge (-)
\( L_w \) — Length of Weir Crest (m)
\( h_c \) — Critical Depth of Weir (m)
\( g \) — Acceleration due to Gravity (m/s²)
\( H \) — Total Head (m)

Explanation: The equation calculates the actual discharge over a broad crested weir by considering the weir geometry, fluid properties, and flow conditions.

3. Importance of Discharge Calculation

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

4. Using the Calculator

Tips: Enter all parameters in appropriate units. Ensure that Total Head is greater than Critical Depth for valid calculation. Use standard values for gravitational acceleration (9.8 m/s²).

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for Coefficient of Discharge?
A: The Coefficient of Discharge typically ranges from 0.6 to 0.9 for broad crested weirs, depending on the weir geometry and flow conditions.

Q2: Why is Critical Depth important in weir calculations?
A: Critical Depth represents the depth where flow energy is minimum for a given discharge, making it a crucial parameter in weir flow calculations.

Q3: When should this formula be used?
A: This formula is specifically designed for broad crested weirs where the weir crest is sufficiently wide to support parallel flow.

Q4: Are there limitations to this equation?
A: The equation assumes ideal flow conditions and may need adjustments for very high velocities, sediment-laden flows, or non-standard weir geometries.

Q5: How accurate is this calculation method?
A: With proper coefficient selection and accurate input parameters, this method provides reliable discharge estimates for engineering applications.