BOILING

Overview

The BOILING function calculates the Boiling number (Bg), a dimensionless number used in heat transfer and boiling phenomena. The Boiling number is defined as the ratio of heat flux to the product of mass flux and latent heat of vaporization. It is commonly used in the analysis of two-phase flow and boiling heat transfer in engineering systems such as boilers, evaporators, and heat exchangers.

The Boiling number is given by:

where:

• $q$ is the heat flux (W/m²)
• $G$ is the two-phase mass flux (kg/m²/s)
• $\Delta H_{vap}$ is the heat of vaporization (J/kg)

For more information, see the fluids.core documentation  and the fluids GitHub repository .

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

Usage

To use the function in Excel:

=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.

The function returns a single value (float): the Boiling number (dimensionless), or an error message (string) if the input is invalid or out-of-range.

Examples

Example 1: Typical Boiling Number Calculation

In Excel:

=BOILING(300, 3000, 800000)

Expected output:

Example 2: Higher Mass Flux

In Excel:

=BOILING(500, 3000, 800000)

Expected output:

Example 3: Higher Heat Flux

In Excel:

=BOILING(300, 6000, 800000)

Expected output:

Example 4: Lower Heat of Vaporization

In Excel:

=BOILING(300, 3000, 400000)

Expected output:

This means, for example, that with a mass flux of 300 kg/m²/s, heat flux of 3000 W/m², and heat of vaporization of 800,000 J/kg, the Boiling number is 0.0000125.

Python Code

import micropip
await micropip.install('fluids')
from fluids.core import Boiling
 
def boiling(G, q, Hvap):
    """
    Calculate the Boiling number (Bg), a dimensionless number for boiling heat transfer.
 
    Args:
        G: Two-phase mass flux in kg/m²/s.
        q: Heat flux in W/m².
        Hvap: Heat of vaporization in J/kg.
 
    Returns:
        The Boiling number (dimensionless, float), or an error message (str) if the input is invalid or out-of-range.
 
    This example function is provided as-is without any representation of accuracy.
    """
    try:
        G = float(G)
        q = float(q)
        Hvap = float(Hvap)
    except Exception:
        return "Invalid input: could not convert arguments to float."
    if G == 0 or Hvap == 0:
        return "Invalid input: G and Hvap must be nonzero."
    try:
        result = Boiling(G, q, Hvap)
    except Exception as e:
        return f"Error: {str(e)}"
    return result

Live Notebook

Edit this function in a live notebook .

Live Demo