Utility Functions¶
Helper functions for calculations and output.
Heat Transfer¶
- enex_analysis_engine.enex_engine.darcy_friction_factor(Re, e_d)[source]¶
Calculate the Darcy friction factor for given Reynolds number and relative roughness.
- Parameters:
Re (float) – Reynolds number
e_d (float) – Relative roughness (e/D)
- Returns:
Darcy friction factor
- Return type:
float
- enex_analysis_engine.enex_engine.calc_h_vertical_plate(T_s, T_inf, L)[source]¶
Calculate natural convection heat transfer coefficient for a vertical plate.
This function calculates the heat transfer coefficient due to natural convection using the Churchill & Chu correlation.
- Parameters:
T_s (float) – Surface temperature [K]
T_inf (float) – Fluid temperature [K]
L (float) – Characteristic length [m]
- Returns:
Heat transfer coefficient [W/m²K]
- Return type:
float
Note
Uses Churchill & Chu correlation. Reference: https://doi.org/10.1016/0017-9310(75)90243-4
COP Calculations¶
Balance Output¶
- enex_analysis_engine.enex_engine.print_balance(balance, decimal=2)[source]¶
Print energy, entropy, or exergy balance dictionary in a formatted way.
This function prints balance information for subsystems, categorizing entries into in, out, consumed, and generated categories.
- Parameters:
balance (dict) – Dictionary containing balance information for subsystems. Structure: {subsystem_name: {category: {symbol: value}}} Categories: ‘in’, ‘out’, ‘con’ (consumed), ‘gen’ (generated)
decimal (int, optional) – Number of decimal places for output (default: 2)
- Returns:
Only prints output
- Return type:
None
Example
>>> balance = { ... "hot water tank": { ... "in": {"E_heater": 5000.0}, ... "out": {"Q_w_tank": 4500.0, "Q_l_tank": 400.0}, ... "con": {"X_c_tank": 100.0} ... } ... } >>> print_balance(balance)