RELATIVE_ROUGHNESS
Excel Usage
=RELATIVE_ROUGHNESS(D, roughness)D(float, required): Diameter of pipe [m]roughness(float, optional, default: 0.00000152): Roughness of pipe wall [m]
Returns (float): Relative Roughness [-]
Examples
Example 1: Simple example
Inputs:
| D | roughness |
|---|---|
| 0.5 | 0.0001 |
Excel formula:
=RELATIVE_ROUGHNESS(0.5, 0.0001)Expected output:
0.0002
Example 2: Steel pipe with default roughness
Inputs:
| D | roughness |
|---|---|
| 1 | 0.00000152 |
Excel formula:
=RELATIVE_ROUGHNESS(1, 0.00000152)Expected output:
0.00000152
Example 3: Rough pipe material
Inputs:
| D | roughness |
|---|---|
| 0.1 | 0.00005 |
Excel formula:
=RELATIVE_ROUGHNESS(0.1, 0.00005)Expected output:
0.0005
Example 4: Smooth pipe (small roughness)
Inputs:
| D | roughness |
|---|---|
| 2 | 0.000001 |
Excel formula:
=RELATIVE_ROUGHNESS(2, 0.000001)Expected output:
5e-7
Python Code
from fluids.core import relative_roughness as fluids_relative_roughness
def relative_roughness(D, roughness=1.52e-06):
"""
Calculate the relative roughness.
See: https://fluids.readthedocs.io/fluids.core.html#fluids.core.relative_roughness
This example function is provided as-is without any representation of accuracy.
Args:
D (float): Diameter of pipe [m]
roughness (float, optional): Roughness of pipe wall [m] Default is 1.52e-06.
Returns:
float: Relative Roughness [-]
"""
try:
D_val = float(D)
roughness_val = float(roughness)
if D_val <= 0:
return "Error: Diameter must be positive"
result = fluids_relative_roughness(D_val, roughness_val)
return float(result)
except Exception as e:
return f"Error: {str(e)}"