多孔質媒体

import numpy as np
import matplotlib.pyplot as plt

########## Begin User Inputs ##########
fluid_viscosity    = 1.781e-5  # dynamic viscosity of the fluid [N·s/m2]
fluid_density      = 1.225     # density of the fluid [kg/m^3]
porous_zone_length = 0.1       # length of the porous zone [m]

# Pressure Vs Velocity Data
velocity = np.array([0.0, 0.1, 0.2, 0.3])          # fluid velocity u [m/s]
pressure_loss = np.array([0.0, 0.01, 0.02, 0.04])  # pressure difference ΔP [N/m2] across the porous zone

########## End User Inputs ##########

# Parabolic curve-fit with ΔP = A * u + B * u^2
coefficients = np.polyfit(velocity, pressure_loss, 2)
B = coefficients[0]
A = coefficients[1]

delta_p_fit = A * velocity + B * velocity**2
plt.scatter(velocity, pressure_loss, color='red', label='data')
plt.plot(velocity, delta_p_fit, label=f'fitting: ΔP = {A:.4f} * u + {B:.4f} * u^2', color='blue')

plt.xlabel('Velocity u [m/s]')
plt.ylabel('Pressure Loss ΔP [Pa]')
plt.title('Pressure Loss vs. Velocity')
plt.legend()
plt.grid(True)
plt.show()

# Limit A to positive value while calculating d
d = max(0, A) / (fluid_viscosity * porous_zone_length)
f = 2 * B / (fluid_density * porous_zone_length)

# Print coefficients
print(f"Curve-fit Coefficients A = {A:.4f}, B = {B:.4f}")
print(f"Viscous  Resistance = {d:.6f} 1/m^{2}")
print(f"Inertial Resistance = {f:.6f} 1/m")

この場合、fluid_viscosity、fluid_density、porous_zone_length、velocity = np.arrayシリーズ、およびpressure_loss = np.arrayシリーズの自身のデータを置き換えます。

または

次のコードを入力して、穴あきプレートベースの計算を実行します。

import numpy as np

########## Begin User Inputs ##########

# physical parameters of the perforated plate
porosity              = 0.8  # porosity, dimensionless, 0 < eps <= 1. 0は使用しません。
hole_diameter         = 0.003  # circular hole diameter [m]
porous_zone_thickness = 0.025  # thickness of porous zone [m]

########## End User Inputs ##########

K = porosity * hole_diameter * hole_diameter * porous_zone_thickness / (32 * porous_zone_thickness + 15 * hole_diameter)

laminar_flow = True
if (laminar_flow):
  # If the flow is laminar
  alpha = 3 * (1 - porosity) / (4 * porosity * porosity * porous_zone_thickness)
else:
  # If the flow is turbulent
  delta_over_D = porous_zone_thickness / hole_diameter
  alpha = 9 * (6 * delta_over_D - 5 * delta_over_D * delta_over_D) / (40 * porosity * porosity * porous_zone_thickness)

viscous_resistance = 1 / K
inertial_resistance = 2 * max(0, alpha)

# Print coefficients
print(f"Coefficients K = {K:.8f}, alpha = {alpha:.8f}")
print(f"Viscous Resistance = {viscous_resistance:.6f} 1/m^{2}")
print(f"Inertial Resistance = {inertial_resistance:.6f} 1/m")

この場合、porosity、hole_diameter、porous_zone_thicknessを自身のデータに置き換えます。