def test_engine_name_slug(self):
# replace spaces with dashes
engine = document.Engine("My Rocket Motor 12")
self.assertEqual(engine.name_slug, "my-rocket-motor-12")
# one word, not much to do
engine = document.Engine("Motor")
self.assertEqual(engine.name_slug, "motor")
# trailing space
engine = document.Engine("Motor ")
self.assertEqual(engine.name_slug, "motor")
# leading space
engine = document.Engine(" Motor")
self.assertEqual(engine.name_slug, "motor")
# blank name
engine = document.Engine("")
self.assertEqual(engine.name_slug, "engine")
# blank name
engine = document.Engine(" ")
self.assertEqual(engine.name_slug, "engine")
# blank name
engine = document.Engine(" ")
self.assertEqual(engine.name_slug, "engine")
# Illegal characters
engine = document.Engine("my **engIne: ")
self.assertEqual(engine.name_slug, "my-engine")
def test_engine_name(self):
engine = document.Engine("test Name")
self.assertEqual(engine.name, "test Name")
self.assertEqual(engine.manufacturer, "")
engine.manufacturer = "python"
self.assertEqual(engine.manufacturer, "python")
def test_write_simple_raspengine(self):
engine = rdoc.Engine("test engine")
engine.manufacturer = "Open Aerospace"
engine.length = 0.1
engine.diameter = 0.2
engine.Isp = 169
engine.m_prop = 1.0
engine.thrust_avg = 1000
str_file = writers.RaspEngine().dump(engine)
# smoke test
self.assertGreater(len(str_file), 10)
# re-read into loader, it should still parse
eng_loader = loaders.RaspEngine()
reloaded_motor = eng_loader.load(str_file)
self.assertGreater(len(reloaded_motor.comments), 0)
self.assertEqual(reloaded_motor.name, "test-engine")
self.assertEqual(reloaded_motor.manufacturer, "Open-Aerospace")
self.assertAlmostEqual(reloaded_motor.diameter, 0.2)
self.assertAlmostEqual(reloaded_motor.length, 0.1)
self.assertAlmostEqual(reloaded_motor.m_prop, 1.0)
self.assertAlmostEqual(reloaded_motor.m_init, 1.0)
self.assertAlmostEqual(reloaded_motor.thrust_avg, 1000.0, places=1)
self.assertAlmostEqual(reloaded_motor.I_total, 1105.0, places=0)
self.assertAlmostEqual(reloaded_motor.t_burn, 1.105)
self.assertAlmostEqual(reloaded_motor.thrust_peak, 1000.0)
self.assertAlmostEqual(reloaded_motor.m_frac, 100.00, places=2)
def test_engine_isp(self):
engine = document.Engine("test Name")
self.assertEqual(engine.Isp, 0)
engine.Isp = 169
self.assertAlmostEqual(engine.Isp, 169)
def test_write_simple_JSBSimAircraft(self):
rocket = rdoc.Rocket("Rocket")
stage0 = rdoc.Stage("Sustainer")
body = rdoc.Bodytube("body", 1, 0.2, diameter=0.33)
engine = rdoc.Engine("test engine")
engine.manufacturer = "Open Aerospace"
engine.length = 0.1
engine.diameter = 0.2
engine.Isp = 169
engine.m_prop = 1.0
engine.thrust_avg = 1000
body.components = [engine]
stage0.components = [
rdoc.Nosecone(rdoc.Noseshape.VONKARMAN, 1, 0.2, 1.0), body
]
rocket.stages = [stage0]
rocket.aero_properties['CD'] = [(0.1, 0.8), (0.5, 0.6), (1.0, 0.8)]
str_file = writers.JSBSimAircraft.dump(rocket)
# print(str_file)
# smoke test
self.assertGreater(len(str_file), 150)
def test_engine_length(self):
engine = document.Engine("test")
# length not set
self.assertEqual(engine.length, 0)
# set directly
engine.length = 25.4
self.assertEqual(engine.length, 25.4)
def test_engine_avgthrust(self):
engine = document.Engine("test Name")
self.assertEqual(engine.thrust_avg, 0)
engine.thrustcurve.append({'t': 0, 'thrust': 500})
engine.thrustcurve.append({'t': 1, 'thrust': 500})
self.assertAlmostEqual(engine.thrust_avg, 500)
def __init__(self, Isp, thrust, impulse, CD):
"""Take variables as input, build a rocket"""
# Create an engine document
engine = document.Engine('Motor')
# Set our design
engine.Isp = Isp
engine.thrust_avg = thrust
engine.I_total = impulse
# volume of propellent needed
prop_volume = engine.m_prop / self.prop_density
# Solve for the radius/length of the fuel grain (assume solid, end burning)
engine.diameter = 2 * (prop_volume / (2 * self.LD * pi))**(1 / 3.0)
engine.length = engine.diameter * self.LD
# Add a nose
nose = document.Nosecone(
document.Noseshape.TANGENT_OGIVE, # Shape
1.0, # shape_parameter
3.5, # mass
engine.diameter * self.Nose_LD, # Length
diameter=engine.diameter,
)
# Payload section
payload = document.Bodytube(
"Payload", # Name
3.5, # mass
0.33, # length, fixed
diameter=engine.diameter,
)
# Body section the size of the engine
body = document.Bodytube(
"Body", # Name
20.0, # mass
engine.length,
diameter=engine.diameter,
)
body.components = [engine]
# Rocket:
rocket = document.Rocket("Rocket")
rocket.aero_properties['CD'] = CD
stage0 = document.Stage("Sustainer")
stage0.components = [nose, payload, body]
rocket.stages = [stage0]
self.rocket = rocket
def test_write_simple_JSBSimEngine(self):
engine = rdoc.Engine("test engine")
engine.manufacturer = "Open Aerospace"
engine.length = 0.1
engine.diameter = 0.2
engine.Isp = 169
engine.m_prop = 1.0
engine.thrust_avg = 1000
str_file = writers.JSBSimEngine.dump(engine)
# print(str_file)
# smoke test
self.assertGreater(len(str_file), 50)
def test_engine_simple_1(self):
engine = document.Engine("test Name")
# minimum to set up real engine
engine.Isp = 123
engine.thrust_avg = 4567
engine.I_total = 15000
self.assertAlmostEqual(engine.Isp, 123)
self.assertAlmostEqual(engine.thrust_avg, 4567)
self.assertAlmostEqual(engine.I_total, 15000)
self.assertAlmostEqual(engine.m_prop, 12.435563572901)
self.assertAlmostEqual(engine.t_burn, 3.2844317932997593)
self.assertAlmostEqual(engine.thrust_peak, 4567)
self.assertAlmostEqual(engine.V_e, 1206.21795)
def test_engine_simple_0(self):
engine = document.Engine("test Name")
# minimum to set up real engine
engine.Isp = 123
engine.thrust_avg = 4567
engine.t_burn = 89
self.assertAlmostEqual(engine.Isp, 123)
self.assertAlmostEqual(engine.thrust_avg, 4567)
self.assertAlmostEqual(engine.t_burn, 89)
self.assertAlmostEqual(engine.m_prop, 336.9730984354)
self.assertAlmostEqual(engine.I_total, 406463)
self.assertAlmostEqual(engine.thrust_peak, 4567)
self.assertAlmostEqual(engine.V_e, 1206.21795)
def test_engine_t_burn(self):
engine = document.Engine("test Name")
engine.t_burn = 123.456
self.assertAlmostEqual(engine.t_burn, 123.456)
def __init__(self):
self.engine = rdoc.Engine("Imported RASP Egine")
def rocket():
# parametric thrust curve:
peak_thrust = random.uniform(3000, 4200)
delay_time = random.uniform(0.5, 30.0)
min_thrust = random.uniform(0.5, 1.0)
growth_rate = random.uniform(1.01, 2.5)
engine = document.Engine("Motor")
engine.m_prop = 70.0 # kg
engine.diameter = 0.28
engine.length = 1.5
isp = 244
max_impulse = engine.m_prop * isp * 9.8
thrust = 1.0
thrustcurve = []
itot = 0
for i in range(500):
t = i * 0.1
if t > delay_time:
thrust = min_thrust * growth_rate**(t - delay_time)
if thrust > 1.0:
thrust = 1.0
thrust_N = thrust * peak_thrust
# compute Total impulse
if i > 0:
x = thrustcurve[-1]['t']
x_1 = t
f_x = thrustcurve[-1]['thrust']
f_x1 = thrust_N
itot += ((x_1 - x) * (f_x1 + f_x)) / 2.0
thrustcurve.append({'t': t, 'thrust': thrust_N})
# When we exceed our impulse budget quit
if itot > max_impulse:
break
engine.thrustcurve = thrustcurve
body.components = [engine]
# Rocket:
rocket = document.Rocket("Rocket")
rocket.aero_properties['CD'] = [
(0.010, 0.699865),
(0.200, 0.580362),
(0.300, 0.586504),
(0.400, 0.595115),
(0.500, 0.606208),
(0.600, 0.619801),
(0.700, 0.635912),
(0.800, 0.654567),
(0.900, 0.675792),
(0.950, 0.681607),
(1.000, 0.688266),
(1.050, 0.725044),
(1.100, 0.722610),
(1.200, 0.657679),
(1.300, 0.595412),
(1.400, 0.572275),
(1.500, 0.550839),
(1.600, 0.530843),
(1.700, 0.512105),
(1.800, 0.494492),
(1.900, 0.477901),
(2.000, 0.462252),
]
stage0 = document.Stage("Sustainer")
stage0.components = [nose, payload, body]
rocket.stages = [stage0]
return rocket
def test_engine_nar_code(self):
# blank engine case
engine = document.Engine("test Name")
self.assertEqual(engine.nar_code, "")
# NAR B motor spec: 2.51 –- 5.00 Ns
# 0% B motor, it's almost zero
engine.thrust_avg = 2.501
engine.t_burn = 1
self.assertEqual(engine.nar_code, "B")
self.assertAlmostEqual(engine.nar_percent, 0, places=1)
# 50% B motor
engine.thrust_avg = 3.755
engine.t_burn = 1
self.assertEqual(engine.nar_code, "B")
self.assertAlmostEqual(engine.nar_percent, 50, places=0)
# 100% B motor, but it rounds up, that's okay I guess
engine.thrust_avg = 4.99999
engine.t_burn = 1
self.assertEqual(engine.nar_code, "B")
self.assertAlmostEqual(engine.nar_percent, 100, places=0)
# NAR N motor spec: 10,200 -- 20,500 Ns
# 0% N motor
engine.thrust_avg = 10200
engine.t_burn = 1
engine.nar_percent
self.assertEqual(engine.nar_code, "M")
self.assertAlmostEqual(engine.nar_percent, 99, places=0)
# 50% N motor
engine.thrust_avg = 10240 + 5150
engine.t_burn = 1
self.assertEqual(engine.nar_code, "N")
self.assertAlmostEqual(engine.nar_percent, 50, places=0)
# 100% N motor
engine.thrust_avg = 20450
engine.t_burn = 1
self.assertEqual(engine.nar_code, "N")
self.assertAlmostEqual(engine.nar_percent, 100, places=0)
# NAR Z motor spec: 41,900,000 -- 83,900,000 Ns
# 0% N motor
engine.thrust_avg = 41.9e6
engine.t_burn = 1
engine.nar_percent
self.assertEqual(engine.nar_code, "Y")
self.assertAlmostEqual(engine.nar_percent, 100, places=0)
# 50% N motor
engine.thrust_avg = 41.9e6 + 10e6
engine.t_burn = 1
self.assertEqual(engine.nar_code, "Z")
self.assertAlmostEqual(engine.nar_percent, 24, places=0)
# 100% N motor
engine.thrust_avg = 83.8e6
engine.t_burn = 1
self.assertEqual(engine.nar_code, "Z")
self.assertAlmostEqual(engine.nar_percent, 100, places=0)
# Greater than Z:
engine.thrust_avg = 500e6
engine.t_burn = 1
self.assertEqual(engine.nar_code, "AC")
self.assertAlmostEqual(engine.nar_percent, 49, places=0)
def test_write_blank_rocksimEngine(self):
engine = rdoc.Engine("test engine")
str_file = writers.RockSimEngine().dump(engine)
# smoketest
self.assertGreater(len(str_file), 50)
def test_engine_ve(self):
engine = document.Engine("test Name")
engine.Isp = 123
self.assertAlmostEqual(engine.V_e, 1206.21795)
def __init__(self):
self.engine = rdoc.Engine("Imported RockSim Engine")