Air Flow Orifice Size Calculator

Orifice Diameter Formula:

\[ D = \sqrt{ \frac{4 Q}{\pi C_d v} } \]

Orifice Diameter (D):

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1. What is the Orifice Diameter Formula?

The orifice diameter formula calculates the required diameter of an orifice plate for a given flow rate, discharge coefficient, and fluid velocity. It is commonly used in fluid mechanics and HVAC system design for airflow measurement and control.

2. How Does the Calculator Work?

The calculator uses the orifice diameter formula:

\[ D = \sqrt{ \frac{4 Q}{\pi C_d v} } \]

Where:

\( D \) — Orifice diameter (m)
\( Q \) — Flow rate (m³/s)
\( C_d \) — Discharge coefficient (dimensionless)
\( v \) — Fluid velocity (m/s)
\( \pi \) — Mathematical constant pi (≈ 3.14159)

Explanation: The formula derives from the continuity equation and accounts for the relationship between flow area, velocity, and discharge characteristics through an orifice.

3. Importance of Orifice Sizing

Details: Proper orifice sizing is crucial for accurate flow measurement, pressure drop control, and efficient system operation in ventilation, pneumatic systems, and fluid transport applications.

4. Using the Calculator

Tips: Enter flow rate in m³/s, discharge coefficient (typically 0.61 for sharp-edged orifices), and desired velocity in m/s. All values must be positive and valid for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical discharge coefficient value?
A: For sharp-edged orifices, C_d is typically 0.61. For rounded or beveled orifices, values may range from 0.8 to 0.98.

Q2: How does velocity affect orifice size?
A: Higher velocities require smaller orifice diameters for the same flow rate, while lower velocities require larger diameters.

Q3: What are common applications of orifice plates?
A: Orifice plates are used in flow meters, pressure regulators, ventilation systems, and fluid control systems for measurement and restriction purposes.

Q4: What factors affect discharge coefficient?
A: Orifice geometry, edge sharpness, Reynolds number, and pressure ratio all influence the discharge coefficient value.

Q5: Can this formula be used for liquids?
A: Yes, the formula applies to both gases and liquids, though discharge coefficients may vary depending on fluid properties and flow conditions.