ENTRANCE_ROUNDED

Overview

Calculate the loss coefficient (K) for a rounded entrance to a pipe flush with a reservoir wall.

Excel Usage

=ENTRANCE_ROUNDED(Di, rc, ent_rnd_method)

• Di (float, required): Inside diameter of pipe [m]
• rc (float, required): Radius of curvature of the entrance [m]
• ent_rnd_method (str, optional, default: “Rennels”): Calculation method

Returns (float): Loss coefficient K for the rounded entrance [-]

Examples

Example 1: Basic rounded entrance with Rennels method

Inputs:

Di	rc
0.1	0.0235

Excel formula:

=ENTRANCE_ROUNDED(0.1, 0.0235)

Expected output:

Result
0.0984

Example 2: Large radius of curvature (generous rounding)

Inputs:

Di	rc
0.1	0.1

Excel formula:

=ENTRANCE_ROUNDED(0.1, 0.1)

Expected output:

Result
0.03

Example 3: Small radius of curvature

Inputs:

Di	rc
0.1	0.005

Excel formula:

=ENTRANCE_ROUNDED(0.1, 0.005)

Expected output:

Result
0.2968

Example 4: Swamee method calculation

Inputs:

Di	rc	ent_rnd_method
0.1	0.0235	Swamee

Excel formula:

=ENTRANCE_ROUNDED(0.1, 0.0235, "Swamee")

Expected output:

Result
0.0682

Python Code

import micropip
await micropip.install(["fluids"])
from fluids.fittings import entrance_rounded as fluids_entrance_rounded

def entrance_rounded(Di, rc, ent_rnd_method='Rennels'):
    """
    Calculate the loss coefficient (K) for a rounded entrance to a pipe flush with a reservoir wall.

    See: https://fluids.readthedocs.io/fluids.fittings.html#fluids.fittings.entrance_rounded

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

    Args:
        Di (float): Inside diameter of pipe [m]
        rc (float): Radius of curvature of the entrance [m]
        ent_rnd_method (str, optional): Calculation method Valid options: Rennels, Swamee, Miller, Idelchik, Harris, Crane. Default is 'Rennels'.

    Returns:
        float: Loss coefficient K for the rounded entrance [-]
    """
    try:
        Di = float(Di)
        rc = float(rc)
    except (ValueError, TypeError):
        return "Error: Di and rc must be numbers."

    if Di <= 0:
        return "Error: Di must be positive."
    if rc < 0:
        return "Error: Rc must be non-negative."

    try:
        result = fluids_entrance_rounded(Di=Di, rc=rc, method=ent_rnd_method)
        return float(result)
    except Exception as e:
        return f"Error: {str(e)}"

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