Nozzles and Venturi nozzles are devices that are inserted in circular cross-section conduit to create pressure difference of static pressure. Based on that pressure difference, flow rate of flowing fluid can be calculated.

- Flow rate for known nozzle size and pressure difference
- Flow velocity in the nozzle inlet
- Discharge coefficient calculation
- Gas expansion coefficient for compressible flow
- Reynolds number

In Selection section you can select values to input. Not selected values will be calculated. You select between:

- flowing fluid - gas or liquid
- pressure after the nozzle or pressure difference at inlet and throat of nozzle
- Nozzle inlet and throat diameter
- density or temperature for gases
- kinematic or dynamic viscosity
- Nozzle type
- calculation within or out of ISO5167 constraints

In Report section you have instant calculation report for input values. From there you can copy/paste report to your text editor.

- Conversion between volumetric and mass flow rate
- Calculation of Reynolds number included
- Applicable for non-compressible liquids and compressible perfect gases
- For three different kind of Nozzles - ISA 1932 nozzle, long radius and Venturi nozzle
- For single-phase fluid, subsonic, non-pulsating flow
- Pressure ratio p
_{2}/p_{1}must be equal or greater than 0.75 - ISO 5167 based calculation

- q - volumetric flow rate
- Fluid flow rate in terms of units of volume per unit of time
- ṁ - mass flow rate
- Fluid flow rate in terms of units of mass per unit of time
- D
_{1}- inlet diameter of nozzle - Internal inlet Nozzle diameter
- D
_{2}- Nozzle throat diameter - Diameter of nozzle throat where maximum flow velocity and minimum pressure is created
- V
_{1}- inlet velocity - Flow velocity in inlet part of Nozzle where flow diameter is D
_{1} - ρ - fluid inlet density
- Density of fluid in inlet part of nozzle in terms of mass per unit of volume
- ν - kinematic viscosity
- Result of fluid particles colliding to each other and moving at different velocities in terms of area per square unit of time
- μ - dynamic viscosity
- Result of fluid particles colliding to each other and moving at different velocities in terms of mass per square unit of distance and time
- κ- isentropic coefficient
- Specific heat ratio
- e - expansion factor
- Coefficient used for compressible flow calculation
- C - coefficient of discharge
- Coefficient used for nozzle, based on the ISO 5167
- R
_{eD}- inlet Reynolds number - Reynolds number calculated in inlet of nozzle
- p
_{1}- pressure on the inlet - Absolute inlet pressure in the nozzle
- p
_{2}- pressure on the outlet - Absolute pressure in the nozzle throat - minimal pressure created by increase of velocity in the nozzle throat
- p
_{1}- p_{2}- pressure drop - Pressure difference between inlet and throat of nozzle
- T - temperature
- Fluid temperature for gas density calculation based on the ideal gas state equation
- R - gas constant
- Gas constant in terms of energy per unit of mass and temperature, for gas density calculation using ideal gas state equation

- Related links:
- Nozzle on Wikipedia
- ISO 5167-3 standard