AIR_NOISE_MUKHERJEE

This function predicts air-cooler fan noise using the Mukherjee correlation from tip speed, shaft power, and fan diameter, with an optional induced-draft adjustment. The model increases with speed and power and decreases with larger fan diameter.

\mathrm{SPL} = 46 + 30\log_{10}(v_{\text{tip}}) + 10\log_{10}(P_{\mathrm{hp}}) - 20\log_{10}(D_{\text{fan}})

When induced draft is selected, a 3 dB reduction is applied.

Excel Usage

=AIR_NOISE_MUKHERJEE(tip_speed, power, fan_diameter, induced)

tip_speed (float, required): Fan blade tip speed (m/s).
power (float, required): Fan shaft power (W).
fan_diameter (float, required): Fan diameter (m).
induced (bool, optional, default: false): Whether the air cooler is induced draft (true) or forced draft (false).

Returns (float): Sound pressure level at 1 m, or an error message if invalid.

Example 1: Forced draft fan

Inputs:

tip_speed	power	fan_diameter	induced
55	20000	4	false

Excel formula:

=AIR_NOISE_MUKHERJEE(55, 20000, 4, FALSE)

Expected output:

100.454

Example 2: Induced draft fan

Inputs:

tip_speed	power	fan_diameter	induced
55	20000	4	true

Excel formula:

=AIR_NOISE_MUKHERJEE(55, 20000, 4, TRUE)

Expected output:

97.4543

Example 3: Larger diameter fan

Inputs:

tip_speed	power	fan_diameter	induced
50	15000	5	false

Excel formula:

=AIR_NOISE_MUKHERJEE(50, 15000, 5, FALSE)

Expected output:

96.025

Example 4: Higher power fan

Inputs:

tip_speed	power	fan_diameter	induced
60	35000	4.5	false

Excel formula:

=AIR_NOISE_MUKHERJEE(60, 35000, 4.5, FALSE)

Expected output:

102.995

Python Code

Show Code

from ht.air_cooler import air_cooler_noise_Mukherjee as ht_air_cooler_noise_Mukherjee

def air_noise_mukherjee(tip_speed, power, fan_diameter, induced=False):
    """
    Compute air cooler noise using the Mukherjee correlation.

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

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

    Args:
        tip_speed (float): Fan blade tip speed (m/s).
        power (float): Fan shaft power (W).
        fan_diameter (float): Fan diameter (m).
        induced (bool, optional): Whether the air cooler is induced draft (true) or forced draft (false). Default is False.

    Returns:
        float: Sound pressure level at 1 m, or an error message if invalid.
    """
    try:
        return ht_air_cooler_noise_Mukherjee(
            tip_speed=tip_speed,
            power=power,
            fan_diameter=fan_diameter,
            induced=induced,
        )
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

tip_speed *

Fan blade tip speed (m/s).

power *

Fan shaft power (W).

fan_diameter *

Fan diameter (m).

induced

Whether the air cooler is induced draft (true) or forced draft (false).