BOILING

Calculates the Boiling number to relate applied heat flux to two-phase mass flux and latent heat in boiling flow.

Excel Usage

=BOILING(G, q, Hvap)

G (float, required): Two-phase mass flux in kg/m²/s
q (float, required): Heat flux in W/m²
Hvap (float, required): Heat of vaporization in J/kg

Returns (float): Boiling number (float), or error message string.

Example 1: Boiling number for moderate mass flux

Inputs:

G	q	Hvap
300	3000	800000

Excel formula:

=BOILING(300, 3000, 800000)

Expected output:

0.0000125

Example 2: Higher mass flux lowers the boiling number

Inputs:

G	q	Hvap
500	3000	800000

Excel formula:

=BOILING(500, 3000, 800000)

Expected output:

0.0000075

Example 3: Higher heat flux raises the boiling number

Inputs:

G	q	Hvap
300	6000	800000

Excel formula:

=BOILING(300, 6000, 800000)

Expected output:

0.000025

Example 4: Lower latent heat raises the boiling number

Inputs:

G	q	Hvap
300	3000	400000

Excel formula:

=BOILING(300, 3000, 400000)

Expected output:

0.000025

Python Code

Show Code

from fluids.core import Boiling as fluids_boiling

def boiling(G, q, Hvap):
    """
    Calculate the Boiling number (Bg), a dimensionless number for boiling heat transfer.

    See: https://fluids.readthedocs.io/fluids.core.html

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

    Args:
        G (float): Two-phase mass flux in kg/m²/s
        q (float): Heat flux in W/m²
        Hvap (float): Heat of vaporization in J/kg

    Returns:
        float: Boiling number (float), or error message string.
    """
    try:
        G = float(G)
        q = float(q)
        Hvap = float(Hvap)
    except (TypeError, ValueError):
        return "Error: G, q, and Hvap must be numeric values."

    if G == 0:
        return "Error: G (mass flux) must be nonzero."
    if Hvap == 0:
        return "Error: Hvap (heat of vaporization) must be nonzero."

    try:
        result = fluids_boiling(G, q, Hvap)
    except Exception as e:
        return f"Error: Failed to calculate Boiling number: {str(e)}"

    return result

Online Calculator

G *

Two-phase mass flux in kg/m²/s

q *

Heat flux in W/m²

Hvap *

Heat of vaporization in J/kg