CTB_NU_GRIMISON

This function computes crossflow tube-bank Nusselt number using the Grimison correlation, which estimates convective heat transfer from Reynolds and Prandtl numbers plus tube-bank geometry.

The model includes tube-row effects for finite bundles and is commonly used for engineering estimates of external-flow heat transfer.

Excel Usage

=CTB_NU_GRIMISON(Re, Pr, Do, tube_rows, pitch_parallel, pitch_normal)

Re (float, required): Reynolds number based on tube outer diameter (-).
Pr (float, required): Prandtl number at bulk conditions (-).
Do (float, required): Tube outer diameter (m).
tube_rows (int, required): Number of tube rows per bundle (-).
pitch_parallel (float, required): Tube pitch parallel to flow (m).
pitch_normal (float, required): Tube pitch normal to flow (m).

Returns (float): Nusselt number for a tube bank, or an error message if invalid.

Example 1: Example with equal pitches

Inputs:

Re	Pr	tube_rows	pitch_parallel	pitch_normal	Do
10263.37	0.708	11	0.05	0.05	0.025

Excel formula:

=CTB_NU_GRIMISON(10263.37, 0.708, 11, 0.05, 0.05, 0.025)

Expected output:

79.0788

Example 2: Example with wider transverse pitch

Inputs:

Re	Pr	tube_rows	pitch_parallel	pitch_normal	Do
10263.37	0.708	11	0.05	0.07	0.025

Excel formula:

=CTB_NU_GRIMISON(10263.37, 0.708, 11, 0.05, 0.07, 0.025)

Expected output:

79.9272

Example 3: Lower Reynolds number case

Inputs:

Re	Pr	tube_rows	pitch_parallel	pitch_normal	Do
800	7	6	0.05	0.05	0.02

Excel formula:

=CTB_NU_GRIMISON(800, 7, 6, 0.05, 0.05, 0.02)

Expected output:

31.1776

Example 4: Higher Reynolds number case

Inputs:

Re	Pr	tube_rows	pitch_parallel	pitch_normal	Do
50000	0.9	15	0.08	0.06	0.03

Excel formula:

=CTB_NU_GRIMISON(50000, 0.9, 15, 0.08, 0.06, 0.03)

Expected output:

1.07524

Python Code

Show Code

from ht.conv_tube_bank import Nu_Grimison_tube_bank as ht_Nu_Grimison_tube_bank

def ctb_nu_grimison(Re, Pr, Do, tube_rows, pitch_parallel, pitch_normal):
    """
    Compute tube bank Nusselt number using the Grimison correlation.

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

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

    Args:
        Re (float): Reynolds number based on tube outer diameter (-).
        Pr (float): Prandtl number at bulk conditions (-).
        Do (float): Tube outer diameter (m).
        tube_rows (int): Number of tube rows per bundle (-).
        pitch_parallel (float): Tube pitch parallel to flow (m).
        pitch_normal (float): Tube pitch normal to flow (m).

    Returns:
        float: Nusselt number for a tube bank, or an error message if invalid.
    """
    try:
        return ht_Nu_Grimison_tube_bank(
            Re=Re,
            Pr=Pr,
            Do=Do,
            tube_rows=tube_rows,
            pitch_parallel=pitch_parallel,
            pitch_normal=pitch_normal,
        )
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

Re *

Reynolds number based on tube outer diameter (-).

Pr *

Prandtl number at bulk conditions (-).

Do *

Tube outer diameter (m).

tube_rows *

Number of tube rows per bundle (-).

pitch_parallel *

Tube pitch parallel to flow (m).

pitch_normal *

Tube pitch normal to flow (m).