TURB_ENTRY_HAUSEN

This function estimates the turbulent entry-region Nusselt number for internal pipe flow using Hausen’s relation. It incorporates Reynolds and Prandtl numbers together with the axial position-to-diameter ratio to represent developing thermal behavior.

Excel Usage

=TURB_ENTRY_HAUSEN(Re, Pr, Di, x)

Re (float, required): Reynolds number (-).
Pr (float, required): Prandtl number (-).
Di (float, required): Pipe inside diameter (m).
x (float, required): Axial distance from the inlet (m).

Returns (float): Turbulent entry-region Nusselt number (-).

Example 1: Hausen turbulent entry example

Inputs:

Re	Pr	Di	x
100000	1.2	0.154	0.05

Excel formula:

=TURB_ENTRY_HAUSEN(100000, 1.2, 0.154, 0.05)

Expected output:

677.723

Example 2: Longer entry length

Inputs:

Re	Pr	Di	x
150000	0.9	0.1	0.2

Excel formula:

=TURB_ENTRY_HAUSEN(150000, 0.9, 0.1, 0.2)

Expected output:

429.388

Example 3: Short entry length

Inputs:

Re	Pr	Di	x
80000	1.5	0.08	0.02

Excel formula:

=TURB_ENTRY_HAUSEN(80000, 1.5, 0.08, 0.02)

Expected output:

706.721

Example 4: Higher Reynolds number

Inputs:

Re	Pr	Di	x
200000	1	0.12	0.1

Excel formula:

=TURB_ENTRY_HAUSEN(200000, 1, 0.12, 0.1)

Expected output:

730.893

Python Code

Show Code

from ht.conv_internal import turbulent_entry_Hausen as ht_turbulent_entry_Hausen

def turb_entry_hausen(Re, Pr, Di, x):
    """
    Calculate turbulent entry-region Nusselt number using Hausen.

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

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

    Args:
        Re (float): Reynolds number (-).
        Pr (float): Prandtl number (-).
        Di (float): Pipe inside diameter (m).
        x (float): Axial distance from the inlet (m).

    Returns:
        float: Turbulent entry-region Nusselt number (-).
    """
    try:
        return ht_turbulent_entry_Hausen(Re=Re, Pr=Pr, Di=Di, x=x)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

Re *

Reynolds number (-).

Pr *

Prandtl number (-).

Di *

Pipe inside diameter (m).

x *

Axial distance from the inlet (m).