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Class: VolumetricFlowRate

The VolumetricFlowRate class is a subclass of Variable that represents the volume of fluid passing a point per unit of time. The base SI unit for volumetric flow rate is cubic meters per second (m3/s).

Supported Units

The following units are supported for initialization and conversion. The class automatically converts all internal values to the base unit (m3/s).

Unit str Conversion Factor to Cubic Meters per Second (m3/s)
cubic meter per second m3/s 1
cubic meter per hour m3/h 13600
liter per second L/s 11000
liter per minute L/min 160000
liter per hour L/h 13600000
cubic foot per second ft3/s 0.0283168
cubic foot per minute ft3/min 0.028316860
cubic foot per hour ft3/h 0.02831683600
US gallon per minute gal/min 0.0037854160
US gallon per hour gal/h 0.003785413600

Class Reference

class VolumetricFlowRate(value, units='m3/s')

A class for handling volumetric flow rate measurements.

Parameters:

  • value : float or int
    The numeric value of the flow rate. Must be a non-negative number.
  • units : str, default='m3/s'
    The unit of the provided value. Must be one of the supported units.

Raises:

  • ValueError : If value is negative.
  • TypeError : If units is not a valid unit.

Examples: 

# Create a VolumetricFlowRate object for 2 m3/h  
>>> v1 = VolumetricFlowRate(2, "m3/h")

# Create a VolumetricFlowRate object for 500 L/min  
>>> v2 = VolumetricFlowRate(500, "L/min")

Properties

Property Type Description
.value float The numeric value of the flow rate, always in cubic meters per second (m3/s).
.original_value float The numeric value as provided during initialization.
.original_unit str The unit as provided during initialization.

Methods

to(target_unit)

Returns a new VolumetricFlowRate object converted to the target_unit. The original object remains unchanged.

Parameters:

  • target_unit : str
    The unit to convert to. Must be one of the supported units.

Returns:

  • VolumetricFlowRate
    A new VolumetricFlowRate object with the converted value and target unit.

Raises:

  • TypeError : If target_unit is not a valid unit.

Examples: 

# Initialize a flow rate of 100 L/s  
>>> flow_L = VolumetricFlowRate(100, "L/s")

# Convert to cubic meters per hour  
>>> flow_m3h = flow_L.to("m3/h")

>>> print(flow\_m3h)  
360.0 m3/h

Class Methods

from_mass_flow(cls, mass_flow: "MassFlowRate", density: "Density")

A class method that converts a MassFlowRate and Density into a VolumetricFlowRate. The conversion formula is:

Qvol​=ρm˙​

where `Qvol is volumetric flow rate, m is mass flow rate, and ρ is density.
Parameters:

  • mass_flow : MassFlowRate
    An instance of the MassFlowRate class.
  • density : Density
    An instance of the Density class.

Returns:

  • VolumetricFlowRate
    A new VolumetricFlowRate object with the calculated value in the base unit (m3/s).

Example: 

# Assuming MassFlowRate and Density classes are available  
>>> m_dot = MassFlowRate(100, "kg/s")  
>>> rho = Density(1000, "kg/m3")

>>> q_vol = VolumetricFlowRate.from_mass_flow(m_dot, rho)

>>> print(q_vol)  
0.1 m3/s

String Representation

  • __str__(self)
    Returns a human-readable string representation of the viscosity, rounded to six decimal places, using its original value, unit, and type.
  • __repr__(self)
    Returns a string representation suitable for developers and debugging, showing the original value, unit, and viscosity type.