NU_CYL_PL62

This function computes the average Nusselt number for forced crossflow over a single cylinder using the 1962 Perkins-Leppert correlation. Reynolds and Prandtl numbers are taken at free-stream conditions, and an optional viscosity-ratio correction is applied when both viscosities are provided.

Nu = \left(0.30Re^{0.5} + 0.10Re^{0.67}\right)Pr^{0.4}\left(\frac{\mu}{\mu_w}\right)^{0.25}

Excel Usage

=NU_CYL_PL62(Re, Pr, mu, muw)

Re (float, required): Reynolds number with respect to cylinder diameter (-).
Pr (float, required): Prandtl number at free stream temperature (-).
mu (float, optional, default: null): Viscosity at free stream temperature (Pa*s).
muw (float, optional, default: null): Viscosity at wall temperature (Pa*s).

Returns (float): Nusselt number with respect to cylinder diameter (-).

Example 1: Perkins-Leppert 1962 example case

Inputs:

Re	Pr
6071	0.7

Excel formula:

=NU_CYL_PL62(6071, 0.7)

Expected output:

49.9716

Example 2: Perkins-Leppert 1962 with viscosity correction

Inputs:

Re	Pr	mu	muw
15000	2.5	0.0011	0.0007

Excel formula:

=NU_CYL_PL62(15000, 2.5, 0.0011, 0.0007)

Expected output:

160.794

Example 3: Perkins-Leppert 1962 at low Reynolds

Inputs:

Re	Pr
200	1

Excel formula:

=NU_CYL_PL62(200, 1)

Expected output:

7.72353

Example 4: Perkins-Leppert 1962 at high Prandtl

Inputs:

Re	Pr
50000	20

Excel formula:

=NU_CYL_PL62(50000, 20)

Expected output:

688.701

Python Code

Show Code

from ht.conv_external import Nu_cylinder_Perkins_Leppert_1962 as ht_Nu_cylinder_Perkins_Leppert_1962

def Nu_cyl_PL62(Re, Pr, mu=None, muw=None):
    """
    Calculate the Nusselt number for crossflow across a single cylinder using the Perkins-Leppert 1962 correlation.

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

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

    Args:
        Re (float): Reynolds number with respect to cylinder diameter (-).
        Pr (float): Prandtl number at free stream temperature (-).
        mu (float, optional): Viscosity at free stream temperature (Pa*s). Default is None.
        muw (float, optional): Viscosity at wall temperature (Pa*s). Default is None.

    Returns:
        float: Nusselt number with respect to cylinder diameter (-).
    """
    try:
        return ht_Nu_cylinder_Perkins_Leppert_1962(Re=Re, Pr=Pr, mu=mu, muw=muw)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

Re *

Reynolds number with respect to cylinder diameter (-).

Pr *

Prandtl number at free stream temperature (-).

Viscosity at free stream temperature (Pa*s).

muw

Viscosity at wall temperature (Pa*s).