NU_DITTUS_BOELTER

Excel Usage

=NU_DITTUS_BOELTER(Re, Pr, heating, revised)
  • Re (float, required): Reynolds number (-)
  • Pr (float, required): Prandtl number (-)
  • heating (bool, optional, default: true): True for heating, False for cooling. Default True.
  • revised (bool, optional, default: true): Use revised coefficient (0.023). Default True.

Returns (float): Nusselt number (-)

Examples

Example 1: Turbulent heating

Inputs:

Re Pr
100000 1.2

Excel formula:

=NU_DITTUS_BOELTER(100000, 1.2)

Expected output:

247.40036

Example 2: Turbulent cooling

Inputs:

Re Pr heating
100000 1.2 false

Excel formula:

=NU_DITTUS_BOELTER(100000, 1.2, FALSE)

Expected output:

242.93059

Example 3: Original coefficients

Inputs:

Re Pr revised
100000 1.2 false

Excel formula:

=NU_DITTUS_BOELTER(100000, 1.2, FALSE)

Expected output:

261.38386

Example 4: High Prandtl

Inputs:

Re Pr
50000 5

Excel formula:

=NU_DITTUS_BOELTER(50000, 5)

Expected output:

251.47328

Python Code

from ht.conv_internal import turbulent_Dittus_Boelter

def nu_dittus_boelter(Re, Pr, heating=True, revised=True):
    """
    Internal convection Nusselt number using Dittus-Boelter.

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

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

    Args:
        Re (float): Reynolds number (-)
        Pr (float): Prandtl number (-)
        heating (bool, optional): True for heating, False for cooling. Default True. Default is True.
        revised (bool, optional): Use revised coefficient (0.023). Default True. Default is True.

    Returns:
        float: Nusselt number (-)
    """
    try:
      Re = float(Re)
      Pr = float(Pr)

      if Re <= 0:
        return "Error: Re must be positive"
      if Pr <= 0:
        return "Error: Pr must be positive"

      return float(turbulent_Dittus_Boelter(Re=Re, Pr=Pr, heating=heating, revised=revised))
    except Exception as e:
        return f"Error: {str(e)}"

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