NU_HPLATE_MCADAMS

This function computes natural-convection Nusselt number for an isothermal horizontal plate with the McAdams correlation from ht. It accounts for buoyancy-assisted (hot upper surface) or opposing (cold upper surface) orientation.

The correlation is based on Rayleigh number behavior:

Ra = Gr\,Pr

and returns a dimensionless plate-length Nusselt number.

Excel Usage

=NU_HPLATE_MCADAMS(Pr, Gr, buoyancy)

Pr (float, required): Prandtl number of the fluid (dimensionless).
Gr (float, required): Grashof number for the plate (dimensionless).
buoyancy (bool, optional, default: true): Whether buoyancy assists free convection (dimensionless).

Returns (float): Nusselt number based on plate length (dimensionless).

Example 1: McAdams hot plate example

Inputs:

Pr	Gr	buoyancy
5.54	321000000	true

Excel formula:

=NU_HPLATE_MCADAMS(5.54, 321000000, TRUE)

Expected output:

181.731

Example 2: McAdams cold plate example

Inputs:

Pr	Gr	buoyancy
5.54	321000000	false

Excel formula:

=NU_HPLATE_MCADAMS(5.54, 321000000, FALSE)

Expected output:

55.4456

Example 3: McAdams low Pr hot plate

Inputs:

Pr	Gr	buoyancy
0.01	321000000	true

Excel formula:

=NU_HPLATE_MCADAMS(0.01, 321000000, TRUE)

Expected output:

22.857

Example 4: McAdams low Pr cold plate

Inputs:

Pr	Gr	buoyancy
0.01	321000000	false

Excel formula:

=NU_HPLATE_MCADAMS(0.01, 321000000, FALSE)

Expected output:

11.4285

Python Code

Show Code

from ht.conv_free_immersed import Nu_horizontal_plate_McAdams as ht_Nu_horizontal_plate_McAdams

def Nu_hplate_McAdams(Pr, Gr, buoyancy=True):
    """
    Calculate the Nusselt number for a horizontal plate using McAdams.

    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 of the fluid (dimensionless).
        Gr (float): Grashof number for the plate (dimensionless).
        buoyancy (bool, optional): Whether buoyancy assists free convection (dimensionless). Default is True.

    Returns:
        float: Nusselt number based on plate length (dimensionless).
    """
    try:
        result = ht_Nu_horizontal_plate_McAdams(Pr, Gr, buoyancy=buoyancy)
        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 of the fluid (dimensionless).

Gr *

Grashof number for the plate (dimensionless).

buoyancy

Whether buoyancy assists free convection (dimensionless).