STROUHAL

Calculates the Strouhal number from oscillation frequency, characteristic length, and flow velocity.

Excel Usage

=STROUHAL(f, L, V)

f (float, required): Characteristic frequency (usually vortex shedding) [Hz]
L (float, required): Characteristic length [m]
V (float, required): Velocity of the fluid [m/s]

Returns (float): Strouhal number [-]

Example 1: Oscillatory flow with frequency-length scaling

Inputs:

f	L	V
8	2	4

Excel formula:

=STROUHAL(8, 2, 4)

Expected output:

4

Example 2: High velocity flow

Inputs:

f	L	V
10	0.5	20

Excel formula:

=STROUHAL(10, 0.5, 20)

Expected output:

0.25

Example 3: Low frequency oscillation

Inputs:

f	L	V
0.5	1	2

Excel formula:

=STROUHAL(0.5, 1, 2)

Expected output:

0.25

Example 4: Typical vortex shedding

Inputs:

f	L	V
20	0.1	5

Excel formula:

=STROUHAL(20, 0.1, 5)

Expected output:

0.4

Python Code

Show Code

from fluids.core import Strouhal as fluids_Strouhal

def strouhal(f, L, V):
    """
    Calculate the Strouhal number.

    See: https://fluids.readthedocs.io/fluids.core.html#fluids.core.Strouhal

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

    Args:
        f (float): Characteristic frequency (usually vortex shedding) [Hz]
        L (float): Characteristic length [m]
        V (float): Velocity of the fluid [m/s]

    Returns:
        float: Strouhal number [-]
    """
    try:
      f_val = float(f)
      L_val = float(L)
      V_val = float(V)

      if V_val == 0:
        return "Error: Velocity must be non-zero"

      result = fluids_Strouhal(f_val, L_val, V_val)
      return float(result)
    except Exception as e:
      return f"Error: {str(e)}"

Online Calculator

f *

Characteristic frequency (usually vortex shedding) [Hz]

L *

Characteristic length [m]

V *

Velocity of the fluid [m/s]