Pressure To Flow Rate Formula

Flow Rate Formula:

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

Discharge Coefficient (C_d):

unitless

Area (A):

m²

Pressure Drop (ΔP):

Density (ρ):

kg/m³

Flow Rate (Q):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Pressure to Flow Rate Formula?

The pressure to flow rate formula calculates the volumetric flow rate of a fluid through an orifice or nozzle based on pressure difference, area, and fluid properties. It's derived from Bernoulli's principle and conservation of energy principles.

2. How Does the Calculator Work?

The calculator uses the flow rate formula:

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

Where:

\( Q \) — Volumetric flow rate (m³/s)
\( C_d \) — Discharge coefficient (unitless)
\( A \) — Cross-sectional area (m²)
\( \Delta P \) — Pressure drop across the orifice (Pa)
\( \rho \) — Fluid density (kg/m³)

Explanation: The formula relates pressure difference to flow rate through an orifice, accounting for energy losses via 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 hydraulic systems.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is the discharge coefficient?
A: The discharge coefficient (C_d) accounts for energy losses and flow contraction through the orifice. It ranges from 0.6 to 1.0 depending on geometry.

Q2: What are typical discharge coefficient values?
A: Sharp-edged orifices: 0.6-0.65, rounded nozzles: 0.9-0.98, venturi meters: 0.95-0.99.

Q3: When is this formula applicable?
A: For incompressible fluids, steady flow, and when the pressure drop is significant compared to the absolute pressure.

Q4: What are the limitations of this formula?
A: Not suitable for compressible fluids, very low Reynolds numbers, or when cavitation occurs. Assumes constant density.

Q5: How does temperature affect the calculation?
A: Temperature affects fluid density (ρ), which directly impacts the flow rate calculation. Use density at operating temperature.