DP_ESDU_HIGH_FIN

This function computes air-side pressure drop across high-fin tube bundles using the ESDU approach. It combines an acceleration term and a friction term that scales with Reynolds number, geometric pitch ratios, and tube-row count.

\Delta P = (K_{\text{acc}} + n_{\text{rows}}K_f)\,\frac{1}{2}\rho v_{\max}^2

The method is intended for turbulent crossflow through finned tube banks and uses minimum-flow-area velocity conditions.

Excel Usage

=DP_ESDU_HIGH_FIN(m, A_min, A_increase, flow_area_contraction_ratio, tube_diameter, pitch_parallel, pitch_normal, tube_rows, rho, mu)
  • m (float, required): Mass flow rate across the tube bank (kg/s).
  • A_min (float, required): Minimum flow area (m^2).
  • A_increase (float, required): Surface area ratio relative to bare tube (-).
  • flow_area_contraction_ratio (float, required): Ratio of minimum to face area (-).
  • tube_diameter (float, required): Bare tube diameter (m).
  • pitch_parallel (float, required): Tube pitch parallel to flow (m).
  • pitch_normal (float, required): Tube pitch normal to flow (m).
  • tube_rows (int, required): Number of tube rows (-).
  • rho (float, required): Air density (kg/m^3).
  • mu (float, required): Air viscosity (Pa*s).

Returns (float): Pressure drop across the finned tube bank (Pa), or an error message if invalid.

Example 1: Baseline high-fin tube bank

Inputs:

m A_min A_increase flow_area_contraction_ratio tube_diameter pitch_parallel pitch_normal tube_rows rho mu
1.2 4 12 0.4 0.02 0.05 0.06 4 1.2 0.000018

Excel formula:

=DP_ESDU_HIGH_FIN(1.2, 4, 12, 0.4, 0.02, 0.05, 0.06, 4, 1.2, 0.000018)

Expected output:

0.279233

Example 2: Higher flow rate and larger tubes

Inputs:

m A_min A_increase flow_area_contraction_ratio tube_diameter pitch_parallel pitch_normal tube_rows rho mu
2 5 10 0.5 0.025 0.06 0.07 6 1.1 0.000019

Excel formula:

=DP_ESDU_HIGH_FIN(2, 5, 10, 0.5, 0.025, 0.06, 0.07, 6, 1.1, 0.000019)

Expected output:

0.678684

Example 3: Compact bundle geometry

Inputs:

m A_min A_increase flow_area_contraction_ratio tube_diameter pitch_parallel pitch_normal tube_rows rho mu
0.8 3.5 14 0.35 0.016 0.045 0.055 3 1.25 0.000017

Excel formula:

=DP_ESDU_HIGH_FIN(0.8, 3.5, 14, 0.35, 0.016, 0.045, 0.055, 3, 1.25, 0.000017)

Expected output:

0.128936

Example 4: Many rows with moderate flow

Inputs:

m A_min A_increase flow_area_contraction_ratio tube_diameter pitch_parallel pitch_normal tube_rows rho mu
1.5 4.5 11 0.45 0.018 0.052 0.062 8 1.18 0.0000185

Excel formula:

=DP_ESDU_HIGH_FIN(1.5, 4.5, 11, 0.45, 0.018, 0.052, 0.062, 8, 1.18, 0.0000185)

Expected output:

0.556944

Python Code

Show Code 
from ht.air_cooler import dP_ESDU_high_fin as ht_dP_ESDU_high_fin

def dP_ESDU_high_fin(m, A_min, A_increase, flow_area_contraction_ratio, tube_diameter, pitch_parallel, pitch_normal, tube_rows, rho, mu):
    """
    Compute air-side pressure drop for high-fin tube banks.

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

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

    Args:
        m (float): Mass flow rate across the tube bank (kg/s).
        A_min (float): Minimum flow area (m^2).
        A_increase (float): Surface area ratio relative to bare tube (-).
        flow_area_contraction_ratio (float): Ratio of minimum to face area (-).
        tube_diameter (float): Bare tube diameter (m).
        pitch_parallel (float): Tube pitch parallel to flow (m).
        pitch_normal (float): Tube pitch normal to flow (m).
        tube_rows (int): Number of tube rows (-).
        rho (float): Air density (kg/m^3).
        mu (float): Air viscosity (Pa*s).

    Returns:
        float: Pressure drop across the finned tube bank (Pa), or an error message if invalid.
    """
    try:
        return ht_dP_ESDU_high_fin(
            m=m,
            A_min=A_min,
            A_increase=A_increase,
            flow_area_contraction_ratio=flow_area_contraction_ratio,
            tube_diameter=tube_diameter,
            pitch_parallel=pitch_parallel,
            pitch_normal=pitch_normal,
            tube_rows=tube_rows,
            rho=rho,
            mu=mu,
        )
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

Mass flow rate across the tube bank (kg/s).
Minimum flow area (m^2).
Surface area ratio relative to bare tube (-).
Ratio of minimum to face area (-).
Bare tube diameter (m).
Tube pitch parallel to flow (m).
Tube pitch normal to flow (m).
Number of tube rows (-).
Air density (kg/m^3).
Air viscosity (Pa*s).