IS_HEATING_PROPERTY

This function determines whether a fluid is being heated by a wall using a temperature-sensitive transport property such as viscosity or Prandtl number. It compares the bulk-fluid property to the wall-condition property and classifies the thermal direction.

For common liquids where viscosity decreases as temperature increases, a lower wall viscosity than bulk viscosity indicates heating. Conversely, a higher wall viscosity indicates cooling.

The result is a boolean indicator: True for heating of the bulk fluid and False for cooling.

Excel Usage

=IS_HEATING_PROPERTY(prop, prop_wall)
  • prop (float, required): Property of the flowing fluid away from the wall (Pa*s).
  • prop_wall (float, required): Property of the fluid at the wall (Pa*s).

Returns (bool): True when the bulk fluid is being heated.

Example 1: Heating from viscosity comparison

Inputs:

prop prop_wall
0.001 0.0012

Excel formula:

=IS_HEATING_PROPERTY(0.001, 0.0012)

Expected output:

false

Example 2: Heating when wall property decreases

Inputs:

prop prop_wall
0.002 0.0015

Excel formula:

=IS_HEATING_PROPERTY(0.002, 0.0015)

Expected output:

true

Example 3: No change in property across wall

Inputs:

prop prop_wall
0.001 0.001

Excel formula:

=IS_HEATING_PROPERTY(0.001, 0.001)

Expected output:

false

Example 4: Large property increase at the wall

Inputs:

prop prop_wall
0.0008 0.002

Excel formula:

=IS_HEATING_PROPERTY(0.0008, 0.002)

Expected output:

false

Python Code

Show Code 
from ht.core import is_heating_property as ht_is_heating_property

def is_heating_property(prop, prop_wall):
    """
    Determine whether a wall heats or cools a flow from a property ratio.

    See: https://ht.readthedocs.io/en/latest/ht.core.html

    This example function is provided as-is without any representation of accuracy.

    Args:
        prop (float): Property of the flowing fluid away from the wall (Pa*s).
        prop_wall (float): Property of the fluid at the wall (Pa*s).

    Returns:
        bool: True when the bulk fluid is being heated.
    """
    try:
        return ht_is_heating_property(prop, prop_wall)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

Property of the flowing fluid away from the wall (Pa*s).
Property of the fluid at the wall (Pa*s).