Total Discharge For Whole Notch Or Weir Calculator

Total Discharge Formula:

\[ Q = \frac{2}{3} \times C_d \times L \times \sqrt{2 \times g} \times H^{3/2} \]

Coefficient of Discharge (Cd):

Length of Notch or Weir (L):

Acceleration due to Gravity (g):

m/s²

Head of Water Over the Crest (H):

Total Discharge (Q):

m³/s

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1. What is Total Discharge for Whole Notch or Weir?

Total discharge through a notch or weir is defined as a measure of the quantity of any fluid flow over unit time. The quantity may be either volume or mass. This calculation is essential in hydraulic engineering and fluid mechanics.

2. How Does the Calculator Work?

The calculator uses the discharge formula:

\[ Q = \frac{2}{3} \times C_d \times L \times \sqrt{2 \times g} \times H^{3/2} \]

Where:

\( Q \) — Total discharge (m³/s)
\( C_d \) — Coefficient of Discharge
\( L \) — Length of Notch or Weir (m)
\( g \) — Acceleration due to Gravity (m/s²)
\( H \) — Head of Water Over the Crest (m)

Explanation: The equation calculates the volumetric flow rate of water over a weir or through a notch, accounting for the geometry and gravitational effects.

3. Importance of Discharge Calculation

Details: Accurate discharge calculation is crucial for designing hydraulic structures, managing water resources, flood control, and irrigation system planning.

4. Using the Calculator

Tips: Enter the coefficient of discharge, length of notch/weir, acceleration due to gravity (default 9.8 m/s²), and head of water over the crest. All values must be positive numbers.

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 0.8 for sharp-crested weirs, depending on the geometry and flow conditions.

Q2: How does head affect the discharge rate?
A: Discharge is proportional to H^(3/2), meaning small changes in head can significantly affect the discharge rate.

Q3: When is this formula applicable?
A: This formula is applicable for sharp-crested weirs and notches where the approach velocity is negligible and the nappe is properly aerated.

Q4: What are the limitations of this equation?
A: The equation assumes ideal flow conditions and may need adjustments for submerged weirs, rounded crests, or significant approach velocities.

Q5: How accurate is this calculation for practical applications?
A: With proper coefficient selection and accurate measurements, this calculation provides good estimates for engineering purposes, though field calibration is recommended for critical applications.