添加联合仿真内容，修改index.md
This commit is contained in:
lujingze committed
1 parent
3994835c65
commit
f0310b6b40
3 files changed
+415
No files matched your search
@@ -0,0 +1,389 @@
|
||||
"""
|
||||
Coupled cryogenic tank and upstream high-pressure helium cylinder example.
|
||||
|
||||
The cryogenic tank still enforces a constant ullage pressure P_work. The
|
||||
helium inlet temperature is fixed to cryo_tank.config.T_IN_HE. The resulting
|
||||
tank-side helium boundary is passed upstream to the cylinder as the imposed
|
||||
mass and energy outflow condition.
|
||||
"""
|
||||
import os
|
||||
import sys
|
||||
from dataclasses import dataclass
|
||||
|
||||
import matplotlib
|
||||
matplotlib.use("Agg")
|
||||
import matplotlib.pyplot as plt
|
||||
import numpy as np
|
||||
from scipy.integrate import solve_ivp
|
||||
|
||||
_REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
|
||||
_SRC_DIR = os.path.join(_REPO_ROOT, "src")
|
||||
if _SRC_DIR not in sys.path:
|
||||
sys.path.insert(0, _SRC_DIR)
|
||||
|
||||
from cryo_tank.config import ( # noqa: E402
|
||||
V_TOTAL, H_TANK, P_WORKING, T_INIT, ULLAGE_FRACTION,
|
||||
MDOT_IN_LN2, T_IN_LN2, MDOT_OUT_LN2,
|
||||
H_CONV_SURFACE, T_ENV, A_TOTAL, T_IN_HE,
|
||||
T_END, RTOL, ATOL,
|
||||
)
|
||||
from cryo_tank import properties as prop # noqa: E402
|
||||
from cryo_tank.heat_leak import MLIHeatLeak # noqa: E402
|
||||
from cryo_tank.tank_model import CryoTank # noqa: E402
|
||||
from cylinder import HighPressureGasCylinder # noqa: E402
|
||||
|
||||
|
||||
OUTPUT_DIR = os.path.join(_REPO_ROOT, "results", "examples")
|
||||
|
||||
|
||||
@dataclass(frozen=True)
|
||||
class HeliumBoundary:
|
||||
"""Helium inlet boundary passed between the tank and cylinder."""
|
||||
|
||||
mdot_to_tank: float
|
||||
edot_to_tank: float
|
||||
source_pressure: float
|
||||
source_temperature: float
|
||||
source_enthalpy: float
|
||||
boundary_enthalpy: float
|
||||
tank_inlet_pressure: float
|
||||
tank_inlet_temperature: float
|
||||
|
||||
|
||||
def build_default_tank():
|
||||
"""Build the default cryogenic tank used by the example."""
|
||||
heat_leak = MLIHeatLeak(A_total=A_TOTAL, q_mli=1.0)
|
||||
return CryoTank(
|
||||
V_total=V_TOTAL,
|
||||
H_tank=H_TANK,
|
||||
P_work=P_WORKING,
|
||||
T_init=T_INIT,
|
||||
ullage_fraction=ULLAGE_FRACTION,
|
||||
mdot_in_ln2=MDOT_IN_LN2,
|
||||
T_in_ln2=T_IN_LN2,
|
||||
mdot_out_ln2=MDOT_OUT_LN2,
|
||||
T_in_he=T_IN_HE,
|
||||
h_conv=H_CONV_SURFACE,
|
||||
T_env=T_ENV,
|
||||
heat_leak_model=heat_leak,
|
||||
)
|
||||
|
||||
|
||||
def sync_fixed_he_inlet_boundary(tank):
|
||||
"""Apply the fixed tank helium inlet boundary from cryo_tank.config."""
|
||||
boundary_h = prop.he_h(T_IN_HE, tank.P_work)
|
||||
tank.T_in_he = T_IN_HE
|
||||
tank.h_in_he = boundary_h
|
||||
return boundary_h, T_IN_HE
|
||||
|
||||
|
||||
def _set_cylinder_conserved_state(cylinder, mass, U):
|
||||
cylinder.mass = mass
|
||||
cylinder.U = U
|
||||
cylinder._update_state()
|
||||
|
||||
|
||||
def _heat_terms(tank, info):
|
||||
T_liq = info['T_liq']
|
||||
T_ull = info['T_ull']
|
||||
liquid_level = info['liquid_level']
|
||||
|
||||
Q_liq_to_ull = tank.h_conv * tank.A_cross * (T_liq - T_ull)
|
||||
Q_leak = tank.heat_leak_model.compute(T_liq, tank.T_env)
|
||||
A_wet, A_dry = tank.wetted_areas(liquid_level)
|
||||
A_total_current = A_wet + A_dry
|
||||
if A_total_current > 0.0:
|
||||
Q_leak_liq = Q_leak * A_wet / A_total_current
|
||||
Q_leak_ull = Q_leak * A_dry / A_total_current
|
||||
else:
|
||||
Q_leak_liq = 0.0
|
||||
Q_leak_ull = 0.0
|
||||
return Q_liq_to_ull, Q_leak, Q_leak_liq, Q_leak_ull
|
||||
|
||||
|
||||
def tank_rates_and_boundary(tank, cylinder, y_tank):
|
||||
"""Return tank ODE rates and the coupled helium inlet boundary."""
|
||||
boundary_h, tank_inlet_T = sync_fixed_he_inlet_boundary(tank)
|
||||
info = tank.derive(y_tank)
|
||||
Q_liq_to_ull, _, Q_leak_liq, Q_leak_ull = _heat_terms(tank, info)
|
||||
|
||||
dm_liq_dt = tank.dm_liq_dt
|
||||
dU_liq_dt = tank._liquid_energy_rate(info, Q_liq_to_ull, Q_leak_liq)
|
||||
dT_ull_dt, mdot_he = tank._solve_ullage_temperature_rate(
|
||||
info, Q_liq_to_ull, Q_leak_ull, dU_liq_dt
|
||||
)
|
||||
|
||||
boundary = HeliumBoundary(
|
||||
mdot_to_tank=mdot_he,
|
||||
edot_to_tank=mdot_he * boundary_h,
|
||||
source_pressure=cylinder.P,
|
||||
source_temperature=cylinder.T,
|
||||
source_enthalpy=cylinder.h,
|
||||
boundary_enthalpy=boundary_h,
|
||||
tank_inlet_pressure=tank.P_work,
|
||||
tank_inlet_temperature=tank_inlet_T,
|
||||
)
|
||||
return np.array([dm_liq_dt, dU_liq_dt, dT_ull_dt]), boundary
|
||||
|
||||
|
||||
def run_system(t_end=T_END, rtol=RTOL, atol=ATOL, max_step=10.0,
|
||||
tank=None, cylinder=None):
|
||||
"""Run the coupled tank-cylinder system.
|
||||
|
||||
Returns a history dict. The cylinder state is included as conserved state
|
||||
variables ``m_cylinder`` and ``U_cylinder`` plus derived pressure,
|
||||
temperature, density, and boundary quantities.
|
||||
"""
|
||||
cylinder = HighPressureGasCylinder() if cylinder is None else cylinder
|
||||
tank = build_default_tank() if tank is None else tank
|
||||
sync_fixed_he_inlet_boundary(tank)
|
||||
|
||||
y0 = np.array([
|
||||
*tank.initial_state(),
|
||||
cylinder.mass,
|
||||
cylinder.U,
|
||||
])
|
||||
|
||||
def rhs(t, y):
|
||||
_set_cylinder_conserved_state(cylinder, y[3], y[4])
|
||||
tank_rates, boundary = tank_rates_and_boundary(tank, cylinder, y[:3])
|
||||
cylinder_mass_rate = -boundary.mdot_to_tank
|
||||
cylinder_energy_rate = -boundary.edot_to_tank
|
||||
return np.array([
|
||||
tank_rates[0],
|
||||
tank_rates[1],
|
||||
tank_rates[2],
|
||||
cylinder_mass_rate,
|
||||
cylinder_energy_rate,
|
||||
])
|
||||
|
||||
def liquid_empty_event(t, y):
|
||||
return y[0]
|
||||
|
||||
liquid_empty_event.terminal = True
|
||||
liquid_empty_event.direction = -1
|
||||
|
||||
def cylinder_pressure_event(t, y):
|
||||
_set_cylinder_conserved_state(cylinder, y[3], y[4])
|
||||
return cylinder.P - tank.P_work
|
||||
|
||||
cylinder_pressure_event.terminal = True
|
||||
cylinder_pressure_event.direction = -1
|
||||
|
||||
sol = solve_ivp(
|
||||
rhs,
|
||||
[0.0, t_end],
|
||||
y0,
|
||||
method='RK45',
|
||||
rtol=rtol,
|
||||
atol=atol,
|
||||
max_step=max_step,
|
||||
events=[liquid_empty_event, cylinder_pressure_event],
|
||||
dense_output=True,
|
||||
)
|
||||
if not sol.success:
|
||||
raise RuntimeError(f"Coupled solve failed: {sol.message}")
|
||||
|
||||
return post_process_history(tank, cylinder, sol.t, sol.y)
|
||||
|
||||
|
||||
def post_process_history(tank, cylinder, t, y):
|
||||
"""Compute tank, cylinder, and boundary histories from solver output."""
|
||||
n = len(t)
|
||||
history = {
|
||||
't': t,
|
||||
'm_liq': y[0],
|
||||
'U_liq': y[1],
|
||||
'T_ull': y[2],
|
||||
'm_cylinder': y[3],
|
||||
'U_cylinder': y[4],
|
||||
'T_liq': np.zeros(n),
|
||||
'T_tank_liq': np.zeros(n),
|
||||
'T_tank_ullage': np.zeros(n),
|
||||
'fill_fraction': np.zeros(n),
|
||||
'liquid_level': np.zeros(n),
|
||||
'V_ull': np.zeros(n),
|
||||
'm_He': np.zeros(n),
|
||||
'U_ull': np.zeros(n),
|
||||
'P_tank': np.zeros(n),
|
||||
'mdot_He': np.zeros(n),
|
||||
'mdot_tank_inlet': np.zeros(n),
|
||||
'mdot_cylinder_out': np.zeros(n),
|
||||
'edot_He': np.zeros(n),
|
||||
'P_cylinder': np.zeros(n),
|
||||
'T_cylinder': np.zeros(n),
|
||||
'rho_cylinder': np.zeros(n),
|
||||
'h_cylinder': np.zeros(n),
|
||||
'P_he_source': np.zeros(n),
|
||||
'T_he_source': np.zeros(n),
|
||||
'h_he_source': np.zeros(n),
|
||||
'P_he_boundary': np.zeros(n),
|
||||
'T_he_boundary': np.zeros(n),
|
||||
'h_he_boundary': np.zeros(n),
|
||||
'P_he_tank_inlet': np.zeros(n),
|
||||
'T_he_tank_inlet': np.zeros(n),
|
||||
'pressure_margin': np.zeros(n),
|
||||
'Q_liq_to_ull': np.zeros(n),
|
||||
'Q_leak': np.zeros(n),
|
||||
'Q_leak_liq': np.zeros(n),
|
||||
'Q_leak_ull': np.zeros(n),
|
||||
}
|
||||
|
||||
for i in range(n):
|
||||
_set_cylinder_conserved_state(cylinder, y[3, i], y[4, i])
|
||||
tank_rates, boundary = tank_rates_and_boundary(tank, cylinder, y[:3, i])
|
||||
info = tank.derive(y[:3, i])
|
||||
Q_liq_to_ull, Q_leak, Q_leak_liq, Q_leak_ull = _heat_terms(tank, info)
|
||||
|
||||
history['T_liq'][i] = info['T_liq']
|
||||
history['T_tank_liq'][i] = info['T_liq']
|
||||
history['T_tank_ullage'][i] = info['T_ull']
|
||||
history['fill_fraction'][i] = info['fill_fraction']
|
||||
history['liquid_level'][i] = info['liquid_level']
|
||||
history['V_ull'][i] = info['V_ull']
|
||||
history['m_He'][i] = info['m_He']
|
||||
history['U_ull'][i] = info['U_ull']
|
||||
history['P_tank'][i] = info['P_He']
|
||||
history['mdot_He'][i] = boundary.mdot_to_tank
|
||||
history['mdot_tank_inlet'][i] = boundary.mdot_to_tank
|
||||
history['mdot_cylinder_out'][i] = boundary.mdot_to_tank
|
||||
history['edot_He'][i] = boundary.edot_to_tank
|
||||
history['P_cylinder'][i] = cylinder.P
|
||||
history['T_cylinder'][i] = cylinder.T
|
||||
history['rho_cylinder'][i] = cylinder.rho
|
||||
history['h_cylinder'][i] = cylinder.h
|
||||
history['P_he_source'][i] = boundary.source_pressure
|
||||
history['T_he_source'][i] = boundary.source_temperature
|
||||
history['h_he_source'][i] = boundary.source_enthalpy
|
||||
history['P_he_boundary'][i] = boundary.tank_inlet_pressure
|
||||
history['T_he_boundary'][i] = boundary.tank_inlet_temperature
|
||||
history['h_he_boundary'][i] = boundary.boundary_enthalpy
|
||||
history['P_he_tank_inlet'][i] = boundary.tank_inlet_pressure
|
||||
history['T_he_tank_inlet'][i] = boundary.tank_inlet_temperature
|
||||
history['pressure_margin'][i] = boundary.source_pressure - boundary.tank_inlet_pressure
|
||||
history['Q_liq_to_ull'][i] = Q_liq_to_ull
|
||||
history['Q_leak'][i] = Q_leak
|
||||
history['Q_leak_liq'][i] = Q_leak_liq
|
||||
history['Q_leak_ull'][i] = Q_leak_ull
|
||||
|
||||
return history
|
||||
|
||||
|
||||
def _save_figure(fig, path):
|
||||
os.makedirs(os.path.dirname(path), exist_ok=True)
|
||||
fig.tight_layout()
|
||||
fig.savefig(path, dpi=140)
|
||||
plt.close(fig)
|
||||
|
||||
|
||||
def plot_requested_outputs(history, output_dir):
|
||||
"""Plot tank and cylinder pressure, temperature, and mass-flow histories."""
|
||||
os.makedirs(output_dir, exist_ok=True)
|
||||
t = history['t']
|
||||
|
||||
fig, (ax_p, ax_t) = plt.subplots(2, 1, figsize=(10, 7), sharex=True)
|
||||
ax_p.plot(t, history['P_tank'] / 1e6)
|
||||
ax_p.set_ylabel('Tank pressure [MPa]')
|
||||
ax_p.grid(True)
|
||||
|
||||
ax_t.plot(t, history['T_tank_liq'], label='Liquid')
|
||||
ax_t.plot(t, history['T_tank_ullage'], label='Ullage')
|
||||
ax_t.plot(t, history['T_he_tank_inlet'], label='He inlet', linestyle='--')
|
||||
ax_t.set_xlabel('Time [s]')
|
||||
ax_t.set_ylabel('Tank temperature [K]')
|
||||
ax_t.grid(True)
|
||||
ax_t.legend()
|
||||
_save_figure(
|
||||
fig, os.path.join(output_dir, 'tank_pressure_temperature.png')
|
||||
)
|
||||
|
||||
fig, ax = plt.subplots(figsize=(10, 4.5))
|
||||
ax.plot(t, history['mdot_tank_inlet'] * 1000.0)
|
||||
ax.set_xlabel('Time [s]')
|
||||
ax.set_ylabel('Tank inlet He mass flow [g/s]')
|
||||
ax.grid(True)
|
||||
_save_figure(fig, os.path.join(output_dir, 'tank_inlet_mass_flow.png'))
|
||||
|
||||
fig, (ax_p, ax_t) = plt.subplots(2, 1, figsize=(10, 7), sharex=True)
|
||||
ax_p.plot(t, history['P_cylinder'] / 1e6)
|
||||
ax_p.set_ylabel('Cylinder pressure [MPa]')
|
||||
ax_p.grid(True)
|
||||
|
||||
ax_t.plot(t, history['T_cylinder'])
|
||||
ax_t.set_xlabel('Time [s]')
|
||||
ax_t.set_ylabel('Cylinder temperature [K]')
|
||||
ax_t.grid(True)
|
||||
_save_figure(
|
||||
fig, os.path.join(output_dir, 'cylinder_pressure_temperature.png')
|
||||
)
|
||||
|
||||
fig, ax = plt.subplots(figsize=(10, 4.5))
|
||||
ax.plot(t, history['mdot_cylinder_out'] * 1000.0)
|
||||
ax.set_xlabel('Time [s]')
|
||||
ax.set_ylabel('Cylinder outlet He mass flow [g/s]')
|
||||
ax.grid(True)
|
||||
_save_figure(fig, os.path.join(output_dir, 'cylinder_mass_flow.png'))
|
||||
|
||||
|
||||
def save_history_csv(history, path):
|
||||
"""Save a 1D history dictionary as CSV."""
|
||||
os.makedirs(os.path.dirname(path), exist_ok=True)
|
||||
names = list(history.keys())
|
||||
data = np.column_stack([np.asarray(history[name]) for name in names])
|
||||
np.savetxt(path, data, delimiter=',', header=','.join(names), comments='')
|
||||
|
||||
|
||||
def save_history_npz(history, path):
|
||||
"""Save a history dictionary as compressed NPZ."""
|
||||
os.makedirs(os.path.dirname(path), exist_ok=True)
|
||||
np.savez_compressed(path, **history)
|
||||
|
||||
|
||||
def main():
|
||||
cylinder = HighPressureGasCylinder()
|
||||
tank = build_default_tank()
|
||||
|
||||
print("Coupled cryo tank + upstream He cylinder")
|
||||
print(f" t_end = {T_END:.3f} s")
|
||||
print(f" tank P_work = {tank.P_work / 1e6:.4f} MPa")
|
||||
print(f" cylinder: P = {cylinder.P / 1e6:.4f} MPa, T = {cylinder.T:.2f} K, "
|
||||
f"m = {cylinder.mass:.4f} kg")
|
||||
print()
|
||||
|
||||
history = run_system(tank=tank, cylinder=cylinder)
|
||||
|
||||
csv_path = os.path.join(OUTPUT_DIR, "cryo_tank_cylinder_system.csv")
|
||||
npz_path = os.path.join(OUTPUT_DIR, "cryo_tank_cylinder_system.npz")
|
||||
save_history_csv(history, csv_path)
|
||||
save_history_npz(history, npz_path)
|
||||
plot_requested_outputs(history, OUTPUT_DIR)
|
||||
|
||||
print("Simulation complete:")
|
||||
print(f" t_final = {history['t'][-1]:.1f} s")
|
||||
print(f" tank fill_fraction: {history['fill_fraction'][0]:.1%} -> "
|
||||
f"{history['fill_fraction'][-1]:.1%}")
|
||||
print(f" tank P: {history['P_tank'][0] / 1e6:.4f} -> "
|
||||
f"{history['P_tank'][-1] / 1e6:.4f} MPa")
|
||||
print(f" tank T_liq: {history['T_tank_liq'][0]:.2f} -> "
|
||||
f"{history['T_tank_liq'][-1]:.2f} K")
|
||||
print(f" tank T_ull: {history['T_tank_ullage'][0]:.2f} -> "
|
||||
f"{history['T_tank_ullage'][-1]:.2f} K")
|
||||
print(f" tank inlet He mdot: {history['mdot_tank_inlet'][0] * 1000:.5f} -> "
|
||||
f"{history['mdot_tank_inlet'][-1] * 1000:.5f} g/s")
|
||||
print(f" cylinder P: {history['P_cylinder'][0] / 1e6:.4f} -> "
|
||||
f"{history['P_cylinder'][-1] / 1e6:.4f} MPa")
|
||||
print(f" cylinder T: {history['T_cylinder'][0]:.2f} -> "
|
||||
f"{history['T_cylinder'][-1]:.2f} K")
|
||||
print(f" cylinder outlet He mdot: {history['mdot_cylinder_out'][0] * 1000:.5f} -> "
|
||||
f"{history['mdot_cylinder_out'][-1] * 1000:.5f} g/s")
|
||||
print(f" cylinder mass: {history['m_cylinder'][0]:.4f} -> "
|
||||
f"{history['m_cylinder'][-1]:.4f} kg")
|
||||
print(f" tank-side He inlet T: {history['T_he_tank_inlet'][0]:.2f} -> "
|
||||
f"{history['T_he_tank_inlet'][-1]:.2f} K")
|
||||
print(f" fixed He boundary h: {history['h_he_boundary'][0]:.2f} -> "
|
||||
f"{history['h_he_boundary'][-1]:.2f} J/kg")
|
||||
print(f"\nOutputs written to {OUTPUT_DIR}/")
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
main()
|
||||
Reference in new issue
Block a user