Air Pressure Flow Rate Calculator

Orifice Flow Equation:

\[ Q = C_d A \sqrt{\frac{2 \Delta P}{\rho}} \]

Discharge Coefficient (C_d):

(dimensionless)

Orifice Area (A):

m²

Pressure Difference (ΔP):

Fluid Density (ρ):

kg/m³

Flow Rate (Q):

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1. What is the Orifice Flow Equation?

The orifice flow equation calculates the volumetric flow rate of a fluid through an orifice based on pressure difference, orifice characteristics, and fluid properties. It is widely used in fluid mechanics and engineering applications.

2. How Does the Calculator Work?

The calculator uses the orifice flow equation:

\[ Q = C_d A \sqrt{\frac{2 \Delta P}{\rho}} \]

Where:

\( Q \) — Volumetric flow rate (m³/s)
\( C_d \) — Discharge coefficient (dimensionless)
\( A \) — Orifice cross-sectional area (m²)
\( \Delta P \) — Pressure difference across orifice (Pa)
\( \rho \) — Fluid density (kg/m³)

Explanation: The equation relates flow rate to the square root of pressure difference, accounting for energy losses through the discharge coefficient.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculation is essential for designing fluid systems, sizing pipes and valves, process control, and optimizing energy efficiency in industrial applications.

4. Using the Calculator

Tips: Enter discharge coefficient (typically 0.6-0.9 for sharp-edged orifices), orifice area in square meters, pressure difference in Pascals, and fluid density in kg/m³. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical discharge coefficient value?
A: For sharp-edged orifices, C_d is typically 0.6-0.65. For rounded orifices, it can be 0.8-0.9 depending on geometry.

Q2: What units should I use for pressure?
A: Pressure must be in Pascals (Pa). 1 bar = 100,000 Pa, 1 psi = 6894.76 Pa.

Q3: Can this equation be used for gases?
A: Yes, but for compressible fluids like gases, additional compressibility factors may be needed for high pressure ratios.

Q4: What is the density of air at standard conditions?
A: Air density is approximately 1.225 kg/m³ at sea level, 15°C, and standard atmospheric pressure.

Q5: When is the orifice equation most accurate?
A: Most accurate for turbulent flow conditions and when the orifice diameter is small compared to pipe diameter (typically d/D < 0.7).