gaspype/tests/benchmark_equalibrium.py

import cantera as ct
import gaspype as gp
import numpy as np
import time
from gaspype import fluid_system

try:
    import cea
    CEA_AVAILABLE = True
except ImportError:
    CEA_AVAILABLE = False

# -----------------------
# Settings
# -----------------------

n_temps = 1000
temps_C = np.linspace(300, 1000, n_temps)     # °C
temperatures = temps_C + 273.15               # K
pressure = 101325                             # Pa (1 atm)

composition = {"CH4": 0.8, "H2O": 0.2}
species_to_track = ["CH4", "H2O", "CO", "CO2", "H2", "O2"]

# -----------------------
# Cantera benchmark
# -----------------------
gas = ct.Solution("gri30.yaml")
gas.TPX = temperatures[0], pressure, composition

eq_cantera = np.zeros((n_temps, len(species_to_track)))

time.sleep(0.5)
t0 = time.perf_counter()
for i, T in enumerate(temperatures):
    gas.TP = T, pressure
    gas.equilibrate('TP')
    eq_cantera[i, :] = [gas.X[gas.species_index(s)] for s in species_to_track]
elapsed_cantera = time.perf_counter() - t0
print(f"Cantera: {elapsed_cantera:.4f} s")

# -----------------------
# Gaspype benchmark
# -----------------------
# Construct the fluid with composition and tracked species
fluid = gp.fluid(composition, fs=fluid_system(species_to_track))

time.sleep(0.5)
t0 = time.perf_counter()
eq_gaspype = gp.equilibrium(fluid, t=temperatures, p=pressure)
elapsed_gaspype = time.perf_counter() - t0
print(f"Gaspype: {elapsed_gaspype:.4f} s")

# Check if elemental balance of result is correct
el_err = np.sum((gp.elements(eq_gaspype) - gp.elements(fluid)).get_n()**2)
assert np.all(el_err < 1e-20)

if CEA_AVAILABLE:
    reac_names = ["CH4", "H2O"]
    prod_names = ["CH4", "H2O", "CO", "CO2", "H2", "O2", "H", "O", "OH"]

    reac = cea.Mixture(reac_names)
    prod = cea.Mixture(prod_names)

    solver = cea.EqSolver(prod, reactants=reac)
    solution = cea.EqSolution(solver)

    input_moles = np.array([8.0, 2.0])
    input_weights = reac.moles_to_weights(input_moles)

    p_bar = pressure * 1e-5  # Convert to bar

    eq_cea = np.zeros((n_temps, len(species_to_track)))

    time.sleep(0.5)
    t0 = time.perf_counter()
    for i, T in enumerate(temperatures):
        solver.solve(solution, cea.TP, T, p_bar, input_weights)
        if solution.converged:
            for j, s in enumerate(species_to_track):
                eq_cea[i, j] = solution.mole_fractions.get(s, 0.0)
    elapsed_cea = time.perf_counter() - t0
    print(f"CEA: {elapsed_cea:.4f} s")

# -----------------------
# Compare first 5 results
# -----------------------
print("\nFirst 5 equilibrium compositions:")
for i in range(5):
    print(f"T = {temperatures[i]:.1f} K")
    print("  Cantera:", eq_cantera[i])
    print("  Gaspype :", eq_gaspype.array_composition[i])
    if CEA_AVAILABLE:
        print("  CEA     :", eq_cea[i])