def test_pi(self):
# Should result in 1/pi
alpha = 0.5 * math.pi
res = IRT_c.divergence_loss_conical_2D(alpha)
self.assertEqual(res, 1 / (0.5 * math.pi))
# should give zero
alpha = math.pi
res = IRT_c.divergence_loss_conical_2D(alpha)
self.assertAlmostEqual(res, 0)
def test_reynolds_throat_wall_hot(self):
# No source was found for replicating this function, but it is a minor function and very simple.
# Instead it is compared to a manual calculation after using the equation in the report
Re_throat = 0
res = IRT_c.Reynolds_throat_wall_hot(reynolds_throat=Re_throat)
exp = 0
self.assertEqual(exp, res)
Re_throat = 1000
exp = 1727.0932103916857
res = IRT_c.Reynolds_throat_wall_hot(reynolds_throat=Re_throat)
self.assertEqual(exp, res)
def test_sheet_barry(self):
# Row 7 to 11 from Barry's sheet
A = 1.4094000E-09 # [m^2] area
P = 1.96800E-04 # [m] perimeter
exp_Dh = 2.86463414634E-05 # [m] Expected hydraulic diameter
res_Dh = IRT_c.hydraulic_diameter(A=A, wetted_perimeter=P)
self.assertAlmostEqual(exp_Dh, res_Dh, places=16)
def test_sheet_barry(self):
# Replicate some results from Barry's sheet ROW 62 (called thrust coefficient loss)
# Barry takes into changes of throat reynolds at throat wall (just like Spisz1965)
area_ratio = 30
Re_throat = 830
Re_throat_wall = IRT_c.Reynolds_throat_wall_cold(
reynolds_throat=Re_throat)
exp = 0.7647
res = IRT_c.viscous_loss(area_ratio=area_ratio,
reynolds_throat_wall=Re_throat_wall)
self.assertAlmostEqual(exp, res, places=4)
Re_throat = 1277
Re_throat_wall = IRT_c.Reynolds_throat_wall_cold(
reynolds_throat=Re_throat)
exp = 0.6166
res = IRT_c.viscous_loss(area_ratio=area_ratio,
reynolds_throat_wall=Re_throat_wall)
self.assertAlmostEqual(exp, res, places=3)
def test_simple(self):
# Test some simple predicitbale inputs
area_ratio = 0
Reynolds_throat_wall = 1
exp = 17.6
res = IRT_c.viscous_loss(area_ratio=area_ratio,
reynolds_throat_wall=Reynolds_throat_wall)
self.assertEqual(res, exp)
Reynolds_throat_wall = 4
exp = 17.6 / 2
res = IRT_c.viscous_loss(area_ratio=area_ratio,
reynolds_throat_wall=Reynolds_throat_wall)
self.assertEqual(res, exp)
area_ratio = 1 / 0.0032
exp = 17.6 * math.e / 2
res = IRT_c.viscous_loss(area_ratio=area_ratio,
reynolds_throat_wall=Reynolds_throat_wall)
self.assertAlmostEqual(res, exp, places=8)
def test_sheet_barry(self):
# Row 31 to 38 from Barry's sheet
gamma = 1.403
Re_throat = 830.193345707
throat_roc = 1e-6
throat_longitudinal_radius = 0.5 * 2.86463e-5
exp = 0.95153 # This is after removing the extra ^2 from D39 "Help 1"
res = IRT_c.throat_boundary_loss(
gamma=gamma,
reynolds_throat=Re_throat,
throat_radius=throat_longitudinal_radius,
throat_roc=throat_roc)
self.assertAlmostEqual(exp, res, places=3)
def test_sheet_rajeev(self):
# Replicate some results from accompanying excel sheet of Barry, with values from Rajeev's model
alpha = math.radians(20.5)
exp = 0.9788
res = IRT_c.divergence_loss_conical_2D(alpha)
self.assertAlmostEqual(res, exp, places=4)
def test_zero(self):
# Test if almost zero input gives expected result (singularity present), should converge to 1
alpha = 1e-8
res = IRT_c.divergence_loss_conical_2D(alpha)
self.assertAlmostEqual(res, 1)