NU_HCYL_METHODS

This function returns available ht method names for horizontal-cylinder natural convection under the provided Prandtl and Grashof conditions. It can either filter by validity range or return all candidate methods.

Method availability is determined from standard free-convection groups:

Ra = Gr\,Pr

and the output is formatted as a one-column 2D array for Excel.

Excel Usage

=NU_HCYL_METHODS(Pr, Gr, check_ranges)

Pr (float, required): Prandtl number at film temperature (dimensionless).
Gr (float, required): Grashof number based on cylinder diameter (dimensionless).
check_ranges (bool, optional, default: true): Whether to filter methods by validity ranges (dimensionless).

Returns (list[list]): Available correlation names as a column list.

Example 1: Horizontal cylinder methods default

Inputs:

Pr	Gr
0.72	10000000

Excel formula:

=NU_HCYL_METHODS(0.72, 10000000)

Expected output:

Morgan
Churchill-Chu
Kuehn & Goldstein

Example 2: Horizontal cylinder methods without range checks

Inputs:

Pr	Gr	check_ranges
0.72	10000000	false

Excel formula:

=NU_HCYL_METHODS(0.72, 10000000, FALSE)

Expected output:

Morgan
Churchill-Chu
Kuehn & Goldstein

Example 3: Horizontal cylinder methods mid Grashof

Inputs:

Pr	Gr
1.1	5000000

Excel formula:

=NU_HCYL_METHODS(1.1, 5000000)

Expected output:

Morgan
Churchill-Chu
Kuehn & Goldstein

Example 4: Horizontal cylinder methods high Grashof

Inputs:

Pr	Gr
0.9	1000000000

Excel formula:

=NU_HCYL_METHODS(0.9, 1000000000)

Expected output:

Morgan
Churchill-Chu
Kuehn & Goldstein

Python Code

Show Code

from ht.conv_free_immersed import Nu_horizontal_cylinder_methods as ht_Nu_horizontal_cylinder_methods

def Nu_hcyl_methods(Pr, Gr, check_ranges=True):
    """
    List available correlations for free convection from a horizontal cylinder.

    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).
        check_ranges (bool, optional): Whether to filter methods by validity ranges (dimensionless). Default is True.

    Returns:
        list[list]: Available correlation names as a column list.
    """
    try:
        methods = ht_Nu_horizontal_cylinder_methods(Pr, Gr, check_ranges=check_ranges)
        if methods is None:
            return "Error: No methods returned"
        return [[method] for method in methods]
    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).

check_ranges

Whether to filter methods by validity ranges (dimensionless).