Rectangular Orifice Flow Calculator

Rectangular Orifice Flow Equation:

\[ Q = \frac{2}{3} C b \sqrt{2g} H^{3/2} \]

Discharge Coefficient (C):

(dimensionless)

Width (b):

meters

Gravity (g):

m/s²

Head (H):

meters

Flow Rate (Q):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Rectangular Orifice Flow?

The rectangular orifice flow equation calculates the volumetric flow rate of liquid through a rectangular opening. It's commonly used in hydraulic engineering, water management, and fluid mechanics applications.

2. How Does the Calculator Work?

The calculator uses the rectangular orifice flow equation:

\[ Q = \frac{2}{3} C b \sqrt{2g} H^{3/2} \]

Where:

\( Q \) — Flow rate (m³/s)
\( C \) — Discharge coefficient (dimensionless, typically 0.62 for sharp-edged orifices)
\( b \) — Width of the orifice (meters)
\( g \) — Acceleration due to gravity (9.81 m/s²)
\( H \) — Head above the orifice centerline (meters)

Explanation: The equation accounts for the geometry of the opening and the energy of the fluid flowing through it.

3. Importance of Flow Calculation

Details: Accurate flow rate calculation is crucial for designing hydraulic systems, sizing pipes and channels, and managing water resources efficiently.

4. Using the Calculator

Tips: Enter the discharge coefficient (typically 0.62 for sharp-edged orifices), width of the orifice, gravity (9.81 m/s² on Earth), and head above the orifice. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical value for the discharge coefficient C?
A: For sharp-edged rectangular orifices, C is typically about 0.62. The value may vary depending on the orifice geometry and edge conditions.

Q2: What units should I use for the inputs?
A: All length dimensions should be in meters, gravity in m/s² (9.81 for Earth), and the result will be in m³/s.

Q3: What is "head" in this context?
A: Head refers to the height of the water surface above the centerline of the orifice, representing the potential energy of the fluid.

Q4: Are there limitations to this equation?
A: This equation assumes steady flow, incompressible fluid, and negligible viscosity effects. It works best for free-flowing conditions.

Q5: Can this be used for submerged orifices?
A: No, this equation is for free-flow conditions. Submerged orifices require a different calculation approach.