ROHSENOW

This function calculates nucleate boiling heat transfer coefficient with the Rohsenow correlation from fluid properties and either excess wall temperature or heat flux.

The classic Rohsenow form relates boiling transfer to property groups and wall superheat:

h = f\left(\rho_l,\rho_g,\mu_l,k_l,C_{p,l},H_{vap},\sigma,C_{sf},n,\Delta T_e\right)

It is a foundational pool-boiling model widely used for engineering calculations.

Excel Usage

=ROHSENOW(rhol, rhog, mul, kl, Cpl, Hvap, sigma, Te, q, Csf, n)

rhol (float, required): Density of the liquid (kg/m^3).
rhog (float, required): Density of the produced gas (kg/m^3).
mul (float, required): Viscosity of liquid (Pa*s).
kl (float, required): Thermal conductivity of liquid (W/m/K).
Cpl (float, required): Heat capacity of liquid (J/kg/K).
Hvap (float, required): Heat of vaporization of the fluid (J/kg).
sigma (float, required): Surface tension of liquid (N/m).
Te (float, optional, default: null): Excess wall temperature (K).
q (float, optional, default: null): Heat flux (W/m^2).
Csf (float, optional, default: 0.013): Rohsenow coefficient specific to fluid and metal (-).
n (float, optional, default: 1.7): Rohsenow constant (-).

Returns (float): Heat transfer coefficient (W/m^2/K), or an error message if invalid.

Example 1: Water boiling with excess temperature

Inputs:

rhol	rhog	mul	kl	Cpl	Hvap	sigma	Te	Csf	n
957.854	0.595593	0.000279	0.68	4217	2257000	0.0589	4.9	0.011	1.26

Excel formula:

=ROHSENOW(957.854, 0.595593, 0.000279, 0.68, 4217, 2257000, 0.0589, 4.9, 0.011, 1.26)

Expected output:

3723.66

Example 2: Water boiling with heat flux

Inputs:

rhol	rhog	mul	kl	Cpl	Hvap	sigma	q	Csf	n
957.854	0.595593	0.000279	0.68	4217	2257000	0.0589	25000	0.011	1.26

Excel formula:

=ROHSENOW(957.854, 0.595593, 0.000279, 0.68, 4217, 2257000, 0.0589, 25000, 0.011, 1.26)

Expected output:

4593.59

Example 3: Higher viscosity and excess temperature

Inputs:

rhol	rhog	mul	kl	Cpl	Hvap	sigma	Te	Csf	n
950	0.8	0.0005	0.62	3900	2100000	0.055	7	0.013	1.7

Excel formula:

=ROHSENOW(950, 0.8, 0.0005, 0.62, 3900, 2100000, 0.055, 7, 0.013, 1.7)

Expected output:

178.801

Example 4: Moderate heat flux with typical properties

Inputs:

rhol	rhog	mul	kl	Cpl	Hvap	sigma	q
980	1.1	0.00035	0.6	3800	2100000	0.05	18000

Excel formula:

=ROHSENOW(980, 1.1, 0.00035, 0.6, 3800, 2100000, 0.05, 18000)

Expected output:

1693.39

Python Code

Show Code

from ht.boiling_nucleic import Rohsenow as ht_Rohsenow

def Rohsenow(rhol, rhog, mul, kl, Cpl, Hvap, sigma, Te=None, q=None, Csf=0.013, n=1.7):
    """
    Compute nucleate boiling heat transfer coefficient using the Rohsenow 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:
        rhol (float): Density of the liquid (kg/m^3).
        rhog (float): Density of the produced gas (kg/m^3).
        mul (float): Viscosity of liquid (Pa*s).
        kl (float): Thermal conductivity of liquid (W/m/K).
        Cpl (float): Heat capacity of liquid (J/kg/K).
        Hvap (float): Heat of vaporization of the fluid (J/kg).
        sigma (float): Surface tension of liquid (N/m).
        Te (float, optional): Excess wall temperature (K). Default is None.
        q (float, optional): Heat flux (W/m^2). Default is None.
        Csf (float, optional): Rohsenow coefficient specific to fluid and metal (-). Default is 0.013.
        n (float, optional): Rohsenow constant (-). Default is 1.7.

    Returns:
        float: Heat transfer coefficient (W/m^2/K), or an error message if invalid.
    """
    try:
        return ht_Rohsenow(
            rhol=rhol,
            rhog=rhog,
            mul=mul,
            kl=kl,
            Cpl=Cpl,
            Hvap=Hvap,
            sigma=sigma,
            Te=Te,
            q=q,
            Csf=Csf,
            n=n,
        )
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

rhol *

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

rhog *

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

mul *

Viscosity of liquid (Pa*s).

kl *

Thermal conductivity of liquid (W/m/K).

Cpl *

Heat capacity of liquid (J/kg/K).

Hvap *

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

sigma *

Surface tension of liquid (N/m).

Excess wall temperature (K).

Heat flux (W/m^2).

Csf

Rohsenow coefficient specific to fluid and metal (-).

Rohsenow constant (-).