ZUBER

This function calculates nucleate boiling critical heat flux using the Zuber correlation for flat plates and related geometries.

The relation is:

q_c = KH_{vap}\rho_g^{0.5}\left[\sigma g(\rho_l-\rho_g)\right]^{0.25}

The constant K is configurable to match different literature conventions.

Excel Usage

=ZUBER(sigma, Hvap, rhol, rhog, K)

sigma (float, required): Surface tension of liquid (N/m).
Hvap (float, required): Heat of vaporization of the fluid (J/kg).
rhol (float, required): Density of the liquid (kg/m^3).
rhog (float, required): Density of the produced gas (kg/m^3).
K (float, optional, default: 0.18): Correlation constant (-).

Returns (float): Critical heat flux (W/m^2), or an error message if invalid.

Example 1: Zuber correlation with K 0.149

Inputs:

sigma	Hvap	rhol	rhog	K
0.0082	272000	567	18.09	0.149

Excel formula:

=ZUBER(0.0082, 272000, 567, 18.09, 0.149)

Expected output:

444307

Example 2: Zuber correlation with K 0.18

Inputs:

sigma	Hvap	rhol	rhog	K
0.0082	272000	567	18.09	0.18

Excel formula:

=ZUBER(0.0082, 272000, 567, 18.09, 0.18)

Expected output:

536747

Example 3: Lower surface tension case

Inputs:

sigma	Hvap	rhol	rhog
0.006	220000	700	12

Excel formula:

=ZUBER(0.006, 220000, 700, 12)

Expected output:

346020

Example 4: Higher surface tension case

Inputs:

sigma	Hvap	rhol	rhog	K
0.012	300000	900	8	0.18

Excel formula:

=ZUBER(0.012, 300000, 900, 8, 0.18)

Expected output:

488884

Python Code

Show Code

from ht.boiling_nucleic import Zuber as ht_Zuber

def Zuber(sigma, Hvap, rhol, rhog, K=0.18):
    """
    Compute nucleate boiling critical heat flux using the Zuber correlation.

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

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

    Args:
        sigma (float): Surface tension of liquid (N/m).
        Hvap (float): Heat of vaporization of the fluid (J/kg).
        rhol (float): Density of the liquid (kg/m^3).
        rhog (float): Density of the produced gas (kg/m^3).
        K (float, optional): Correlation constant (-). Default is 0.18.

    Returns:
        float: Critical heat flux (W/m^2), or an error message if invalid.
    """
    try:
        return ht_Zuber(sigma=sigma, Hvap=Hvap, rhol=rhol, rhog=rhog, K=K)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

sigma *

Surface tension of liquid (N/m).

Hvap *

Heat of vaporization of the fluid (J/kg).

rhol *

Density of the liquid (kg/m^3).

rhog *

Density of the produced gas (kg/m^3).

Correlation constant (-).