BLASIUS
Calculates the Darcy friction factor for smooth-pipe turbulent flow with the classic Blasius empirical correlation. This wrapper is useful for quick estimates when the Reynolds number is in the usual engineering range for the correlation and wall roughness effects can be neglected.
The correlation is:
f_d = \frac{0.3164}{Re^{0.25}}
Because the formula depends only on Reynolds number, it is especially convenient for screening calculations and comparisons against more general rough-pipe correlations.
Excel Usage
=BLASIUS(re)re(float, required): Reynolds number [-]
Returns (float): Darcy friction factor for smooth-pipe turbulent flow [-]
Example 1: Reynolds number 10,000
Inputs:
| re |
|---|
| 10000 |
Excel formula:
=BLASIUS(10000)Expected output:
0.03164
Example 2: Reynolds number 50,000
Inputs:
| re |
|---|
| 50000 |
Excel formula:
=BLASIUS(50000)Expected output:
0.0211589
Example 3: Reynolds number 100,000
Inputs:
| re |
|---|
| 100000 |
Excel formula:
=BLASIUS(100000)Expected output:
0.0177925
Example 4: Reynolds number 5,000
Inputs:
| re |
|---|
| 5000 |
Excel formula:
=BLASIUS(5000)Expected output:
0.0376265
Python Code
Show Code
from fluids.friction import Blasius as fluids_blasius
def blasius(re):
"""
Calculates Darcy friction factor for turbulent flow in smooth pipes using the Blasius correlation.
See: https://fluids.readthedocs.io/fluids.friction.html#fluids.friction.Blasius
This example function is provided as-is without any representation of accuracy.
Args:
re (float): Reynolds number [-]
Returns:
float: Darcy friction factor for smooth-pipe turbulent flow [-]
"""
try:
re_val = float(re)
if re_val <= 0:
return "Error: Reynolds number must be positive."
result = fluids_blasius(re_val)
if result != result:
return "Error: Result is NaN."
if result == float('inf') or result == float('-inf'):
return "Error: Result is not finite."
return float(result)
except Exception as e:
return f"Error: {str(e)}"