JAKOB
Excel Usage
=JAKOB(Cp, Hvap, Te)Cp(float, required): Heat capacity of the fluid [J/kg/K]Hvap(float, required): Enthalpy of vaporization [J/kg]Te(float, required): Temperature difference above saturation boiling temperature [K]
Returns (float): Jakob number [-]
Examples
Example 1: Water boiling with Cp=4000, Hvap=2E6, Te=10
Inputs:
| Cp | Hvap | Te |
|---|---|---|
| 4000 | 2000000 | 10 |
Excel formula:
=JAKOB(4000, 2000000, 10)Expected output:
0.02
Example 2: Small superheat (Jakob < 1)
Inputs:
| Cp | Hvap | Te |
|---|---|---|
| 2000 | 2500000 | 5 |
Excel formula:
=JAKOB(2000, 2500000, 5)Expected output:
0.004
Example 3: Large superheat
Inputs:
| Cp | Hvap | Te |
|---|---|---|
| 3500 | 1500000 | 30 |
Excel formula:
=JAKOB(3500, 1500000, 30)Expected output:
0.07
Example 4: Fluid with high heat capacity
Inputs:
| Cp | Hvap | Te |
|---|---|---|
| 6000 | 2000000 | 15 |
Excel formula:
=JAKOB(6000, 2000000, 15)Expected output:
0.045
Python Code
from fluids.core import Jakob as fluids_Jakob
def jakob(Cp, Hvap, Te):
"""
Calculate the Jakob number for boiling fluid.
See: https://fluids.readthedocs.io/fluids.core.html#fluids.core.Jakob
This example function is provided as-is without any representation of accuracy.
Args:
Cp (float): Heat capacity of the fluid [J/kg/K]
Hvap (float): Enthalpy of vaporization [J/kg]
Te (float): Temperature difference above saturation boiling temperature [K]
Returns:
float: Jakob number [-]
"""
try:
Cp = float(Cp)
Hvap = float(Hvap)
Te = float(Te)
if Cp < 0:
return "Error: Heat capacity Cp must be non-negative"
if Hvap <= 0:
return "Error: Enthalpy of vaporization Hvap must be positive"
if Te < 0:
return "Error: Temperature difference Te must be non-negative"
result = fluids_Jakob(Cp, Hvap, Te)
return float(result)
except (TypeError, ValueError) as e:
return f"Error: Invalid input - {str(e)}"
except Exception as e:
return f"Error: {str(e)}"