COOPER
This function computes a nucleate pool-boiling heat transfer coefficient using the Cooper correlation. The method requires either excess wall temperature or heat flux and incorporates reduced pressure, molecular weight, and a roughness term.
In common form, the relation scales as:
h \propto q^{0.67}\left(\frac{P}{P_c}\right)^{a}\left[-\log_{10}\left(\frac{P}{P_c}\right)\right]^{-0.55}MW^{-0.5}
where the exponent a depends on the roughness parameter. This is a standard empirical approach for nucleate boiling estimation.
Excel Usage
=COOPER(P, Pc, MW, Te, q, Rp)
P(float, required): Saturation pressure (Pa).Pc(float, required): Critical pressure (Pa).MW(float, required): Molecular weight (g/mol).Te(float, optional, default: null): Excess wall temperature (K).q(float, optional, default: null): Heat flux (W/m^2).Rp(float, optional, default: 0.000001): Surface roughness parameter (m).
Returns (float): Heat transfer coefficient (W/m^2/K), or an error message if invalid.
Example 1: Example with excess temperature
Inputs:
| P | Pc | MW | Te |
|---|---|---|---|
| 101325 | 22048321 | 18.02 | 4.3 |
Excel formula:
=COOPER(101325, 22048321, 18.02, 4.3)
Expected output:
1558.14
Example 2: Using heat flux input
Inputs:
| P | Pc | MW | q |
|---|---|---|---|
| 101325 | 22048321 | 18.02 | 100000 |
Excel formula:
=COOPER(101325, 22048321, 18.02, 100000)
Expected output:
9530.96
Example 3: Rough surface with higher pressure
Inputs:
| P | Pc | MW | Te | Rp |
|---|---|---|---|---|
| 500000 | 4000000 | 44 | 10 | 0.000002 |
Excel formula:
=COOPER(500000, 4000000, 44, 10, 0.000002)
Expected output:
52990.3
Example 4: Alternate fluid with heat flux
Inputs:
| P | Pc | MW | q | Rp |
|---|---|---|---|---|
| 200000 | 5000000 | 30 | 50000 | 0.000005 |
Excel formula:
=COOPER(200000, 5000000, 30, 50000, 0.000005)
Expected output:
12524.6
Python Code
Show Code
from ht.boiling_flow import Cooper as ht_Cooper
def Cooper(P, Pc, MW, Te=None, q=None, Rp=1e-06):
"""
Compute the Cooper nucleate boiling heat transfer coefficient.
See: https://ht.readthedocs.io/en/latest/ht.boiling_flow.html
This example function is provided as-is without any representation of accuracy.
Args:
P (float): Saturation pressure (Pa).
Pc (float): Critical pressure (Pa).
MW (float): Molecular weight (g/mol).
Te (float, optional): Excess wall temperature (K). Default is None.
q (float, optional): Heat flux (W/m^2). Default is None.
Rp (float, optional): Surface roughness parameter (m). Default is 1e-06.
Returns:
float: Heat transfer coefficient (W/m^2/K), or an error message if invalid.
"""
try:
if Te is None and q is None:
return "Error: Te or q must be provided"
return ht_Cooper(P=P, Pc=Pc, MW=MW, Te=Te, q=q, Rp=Rp)
except Exception as e:
return f"Error: {str(e)}"