Head For Discharge For Entire Triangular Weir Calculator

Formula Used:

\[ Height\ of\ Water\ above\ Crest\ of\ Weir = \left( \frac{Discharge\ through\ Triangular\ Weir}{\left( \frac{8}{15} \right) \times Coefficient\ of\ Discharge \times \sqrt{2 \times Acceleration\ due\ to\ Gravity} \times \tan\left( \frac{\Theta}{2} \right)} \right)^{\frac{2}{5}} \]

Discharge through Triangular Weir (Qtri):

m³/s

Coefficient of Discharge (Cd):

Acceleration due to Gravity (g):

m/s²

Theta (θ):

radians

Height of Water above Crest of Weir (Sw):

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1. What is the Head for Discharge for Entire Triangular Weir Formula?

The Head for Discharge for Entire Triangular Weir formula calculates the height of water above the crest of a triangular weir based on the discharge rate, coefficient of discharge, gravitational acceleration, and the angle of the weir. This is essential for hydraulic engineering and flow measurement in open channels.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

Discharge through Triangular Weir (Qtri) — Flow rate in cubic meters per second (m³/s)
Coefficient of Discharge (Cd) — Dimensionless coefficient representing efficiency
Acceleration due to Gravity (g) — Gravitational acceleration in m/s² (typically 9.8 m/s²)
Theta (θ) — Angle of the triangular weir in radians

Explanation: The formula accounts for the geometric properties of the triangular weir and the hydraulic characteristics of the flow to determine the water height above the weir crest.

3. Importance of Head Calculation

Details: Accurate head calculation is crucial for designing weirs, measuring flow rates in open channels, and ensuring proper water management in irrigation systems, wastewater treatment plants, and hydraulic structures.

4. Using the Calculator

Tips: Enter discharge in m³/s, coefficient of discharge (typically between 0.6-0.7 for triangular weirs), gravitational acceleration (9.8 m/s²), and the weir angle in radians. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a triangular weir?
A: A triangular weir is a flow measurement device with a V-shaped notch used to measure discharge in open channels.

Q2: Why use a triangular weir instead of rectangular?
A: Triangular weirs are more sensitive to low flow rates and provide better accuracy for small discharges.

Q3: What are typical values for coefficient of discharge?
A: For triangular weirs, Cd typically ranges from 0.58 to 0.62, but can vary based on weir geometry and flow conditions.

Q4: How to convert degrees to radians?
A: Multiply degrees by π/180 (approximately 0.0174533) to get radians.

Q5: What are the limitations of this formula?
A: The formula assumes ideal flow conditions and may need adjustments for viscosity effects, surface tension, and weir construction details.