NU_HCYL_MORGAN

This function computes the Morgan free-convection correlation for an isothermal horizontal cylinder using the ht library implementation. It accepts Prandtl and Grashof numbers as dimensionless inputs.

The relation is piecewise power-law in Rayleigh number:

Nu = C\,Ra^n,\qquad Ra = Gr\,Pr

and returns a diameter-based dimensionless Nusselt number.

Excel Usage

=NU_HCYL_MORGAN(Pr, Gr)

Pr (float, required): Prandtl number at film temperature (dimensionless).
Gr (float, required): Grashof number based on cylinder diameter (dimensionless).

Returns (float): Nusselt number based on cylinder diameter (dimensionless).

Example 1: Morgan example

Inputs:

Pr	Gr
0.69	2630000000

Excel formula:

=NU_HCYL_MORGAN(0.69, 2630000000)

Expected output:

151.388

Example 2: Morgan low Grashof

Inputs:

Pr	Gr
0.7	100

Excel formula:

=NU_HCYL_MORGAN(0.7, 100)

Expected output:

1.91282

Example 3: Morgan mid Grashof

Inputs:

Pr	Gr
1.2	1000000

Excel formula:

=NU_HCYL_MORGAN(1.2, 1000000)

Expected output:

15.8868

Example 4: Morgan high Grashof

Inputs:

Pr	Gr
0.9	10000000000

Excel formula:

=NU_HCYL_MORGAN(0.9, 10000000000)

Expected output:

258.032

Python Code

Show Code

from ht.conv_free_immersed import Nu_horizontal_cylinder_Morgan as ht_Nu_horizontal_cylinder_Morgan

def Nu_hcyl_Morgan(Pr, Gr):
    """
    Calculate the Nusselt number for a horizontal cylinder using Morgan.

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

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

    Args:
        Pr (float): Prandtl number at film temperature (dimensionless).
        Gr (float): Grashof number based on cylinder diameter (dimensionless).

    Returns:
        float: Nusselt number based on cylinder diameter (dimensionless).
    """
    try:
        result = ht_Nu_horizontal_cylinder_Morgan(Pr, Gr)
        if result is None:
            return "Error: Result is None"
        return float(result)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

Pr *

Prandtl number at film temperature (dimensionless).

Gr *

Grashof number based on cylinder diameter (dimensionless).