comparing conduits to analytical solution in integration test

tests/integration/Flow_in_straight_conduit.py

@@ -5,8 +5,13 @@
     import openpnm as op
     import numpy as np
 
+    mu = 1.0
+    Pin = 1.0
+    Pout = 0.0
     diameters = [0.9, 1.0, 1.1, 1.5]
-    for D in diameters:
+    Q = np.pi*(np.array(diameters)/2)**4/(8*mu*4) * (Pin - Pout)
+
+    for i, D in enumerate(diameters):
         pn5 = op.network.Cubic(shape=[5, 1, 1], spacing=1)
         pn5['pore.diameter'] = D
         pn5['throat.diameter'] = D
@@ -24,26 +29,27 @@
         pn3.regenerate_models()
 
         ph1 = op.phase.Phase(network=pn3)
-        ph1['pore.viscosity'] = 1.0
+        ph1['pore.viscosity'] = mu
         ph1.add_model(
             propname='throat.hydraulic_conductance',
             model=op.models.physics.hydraulic_conductance.generic_hydraulic)
 
         ph2 = op.phase.Phase(network=pn5)
-        ph2['pore.viscosity'] = 1.0
+        ph2['pore.viscosity'] = mu
         ph2.add_model(
             propname='throat.hydraulic_conductance',
             model=op.models.physics.hydraulic_conductance.generic_hydraulic)
 
         sf1 = op.algorithms.StokesFlow(network=pn3, phase=ph1)
-        sf1.set_value_BC(pores=pn3.pores('xmin'), values=1.0)
-        sf1.set_value_BC(pores=pn3.pores('xmax'), values=0.0)
+        sf1.set_value_BC(pores=pn3.pores('xmin'), values=Pin)
+        sf1.set_value_BC(pores=pn3.pores('xmax'), values=Pout)
         sf1.run()
         r1 = sf1.rate(pores=pn3.pores('xmin'))
 
         sf2 = op.algorithms.StokesFlow(network=pn5, phase=ph1)
-        sf2.set_value_BC(pores=pn5.pores('xmin'), values=1.0)
-        sf2.set_value_BC(pores=pn5.pores('xmax'), values=0.0)
+        sf2.set_value_BC(pores=pn5.pores('xmin'), values=Pin)
+        sf2.set_value_BC(pores=pn5.pores('xmax'), values=Pout)
         sf2.run()
         r2 = sf2.rate(pores=pn5.pores('xmin'))
         assert np.allclose(r1, r2, atol=0, rtol=1e-10)
+        assert np.allclose(r1, Q[i], atol=0, rtol=1e-10)