def distance(vinit="10.0 m/s", acc="9.80665 m/s**2", time="30 s"):
"""
Calculate the distance traveled by an object with some initial velocity,
and a constant acceleration over a given time.
Note that any units available in RocketUnits may be used
as inputs for vinit, acc and time.
Args:
vinit (float): Initial velocity, m/s
acc (float): Acceleration(standard gravity=9.80665), m/s**2
time (float): Time, s
Returns:
float: Distance traveled, m
"""
# let Units inspect the distance interface and get locals() values
my_units = Units(distance, vars())
GETVAL = my_units.get_input_value # a convenience method
# let Units convert inputs into internal units
vinit = GETVAL("vinit")
acc = my_units.get_input_value("acc")
time = my_units.get_input_value("time")
# with internal units, do the calculation
d = vinit * time + acc * time**2 / 2.0
return d # d will always be in units of meters, m
def __init__(self, x="4 ft**2", y="None psia", pdiff="10 psid"):
self.my_io = Units( self.__class__, locals() )
self.x = self.my_io.get_input_value("x")
self.y = self.my_io.get_input_value("y")
self.pdiff = self.my_io.get_input_value("pdiff")
self.my_io.set_vars_dict( vars(self) )
self.my_io.set_print_template( template="%s = %s %s")
class Bar:
def __init__(self, xxx, x="4 ft**2", y="5 s", z="6 ft/s**2", j=66,
output_units="Both"):
self.my_io = Units( self.__class__, locals() )
self.x = self.my_io.get_input_value("x")
self.y = self.my_io.get_input_value("y")
self.z = self.my_io.get_input_value("z")
self.j = j
self.xxx = self.my_io.get_input_value("xxx", def_units="deg")
self.xxx_x3 = 3.0 * self.xxx
self.my_io.set_units_same_as("xxx_x3", "xxx")
def summ_print(self):
# give Units object the current locals()/vars()
self.my_io.set_vars_dict( vars(self) )
self.my_io.set_print_template( template="%12s = %-45s %s")
u_print = self.my_io.u_print
for name in self.my_io.default_unitsD.keys():
u_print(name)
print()
def __init__(self, xxx, x="4 ft**2", y="5 s", z="6 ft/s**2", j=66,
output_units="Both"):
self.my_io = Units( self.__class__, locals() )
self.x = self.my_io.get_input_value("x")
self.y = self.my_io.get_input_value("y")
self.z = self.my_io.get_input_value("z")
self.j = j
self.xxx = self.my_io.get_input_value("xxx", def_units="deg")
self.xxx_x3 = 3.0 * self.xxx
self.my_io.set_units_same_as("xxx_x3", "xxx")
def __init__(self, xxx, x="4 ft**2", y="5 s", z="6 ft/s**2", j=66, k=99,
output_units="Both", my_flag=True):
self.my_io = Units( self.__class__, locals() )
self.x = self.my_io.get_input_value("x")
self.y = self.my_io.get_input_value("y")
self.z = self.my_io.get_input_value("z")
self.j = j
self.xxx = self.my_io.get_input_value("xxx", def_units="deg")
self.my_io.set_vars_dict( vars(self) )
self.my_io.set_print_template( template="%s = %s %s")
def __init__(self, d1="1 in", d2="2 inch", a1="1 in**2", a2="2 in**2",
v1="1 in**3", v2="2 inch**3", output_units="English"):
self.my_io = Units( self.__class__, locals() )
self.d1 = self.my_io.get_input_value("d1")
self.d2 = self.my_io.get_input_value("d2")
self.a1 = self.my_io.get_input_value("a1")
self.a2 = self.my_io.get_input_value("a2")
self.v1 = self.my_io.get_input_value("v1")
self.v2 = self.my_io.get_input_value("v2")
self.my_io.set_vars_dict( vars(self) )
self.my_io.set_print_template( template="%s = %s %s")
class RocketDeltaV:
gc = 32.174 # gravitational converstion factor lbm-ft/lbf-sec**2
def __init__(self,
Isp="330.0 sec",
mass="10000.0 lbm",
prop_mass_frac=0.8):
"""
Calculate the ideal rocket velocity based on the percent of propellant burned.
(see: https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation)
(or: https://www.translatorscafe.com/unit-converter/en-US/calculator/rocket-equation/)
Args:
Isp (float): specific impulse, sec (https://en.wikipedia.org/wiki/Specific_impulse)
mass (float): total rocket mass, lbm
prop_mass_frac (float): mass fraction of rocket that is propellant
"""
# let Units inspect the class interface and get locals() values
self.my_io = Units(self.__class__, locals())
# let Units convert inputs into internal units (sec and lbm)
self.Isp = self.my_io.get_input_value("Isp")
self.mass = self.my_io.get_input_value("mass")
self.prop_mass_frac = prop_mass_frac # note: mass fraction is unitless
def delta_v(self, pcent_burned=100.0):
"""
Assuming a given percentage of the propellant is burned,
calculate the ideal change in velocity, ft/sec
Args:
pcent_burned (float): percent of propellant burned
Returns:
delta_v (float): ideal rocket velocity, ft/s
"""
if pcent_burned < 0.0 or pcent_burned > 100.0:
raise Exception("pcent_burned must be >=0 and <=100")
prop_mass = (pcent_burned / 100.0) * self.prop_mass_frac * self.mass
delta_v = self.gc * self.Isp * log(self.mass / (self.mass - prop_mass))
return delta_v # ft/s
def __init__(self,
Isp="330.0 sec",
mass="10000.0 lbm",
prop_mass_frac=0.8):
"""
Calculate the ideal rocket velocity based on the percent of propellant burned.
(see: https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation)
(or: https://www.translatorscafe.com/unit-converter/en-US/calculator/rocket-equation/)
Args:
Isp (float): specific impulse, sec (https://en.wikipedia.org/wiki/Specific_impulse)
mass (float): total rocket mass, lbm
prop_mass_frac (float): mass fraction of rocket that is propellant
"""
# let Units inspect the class interface and get locals() values
self.my_io = Units(self.__class__, locals())
# let Units convert inputs into internal units (sec and lbm)
self.Isp = self.my_io.get_input_value("Isp")
self.mass = self.my_io.get_input_value("mass")
self.prop_mass_frac = prop_mass_frac # note: mass fraction is unitless
class Bar:
def __init__(self,
xxx,
x="4 ft**2",
y="5 s",
z="6 ft/s**2",
j=66,
output_units="Both"):
self.my_io = Units(self.__class__, locals())
self.x = self.my_io.get_input_value("x")
self.y = self.my_io.get_input_value("y")
self.z = self.my_io.get_input_value("z")
self.j = j
self.xxx = self.my_io.get_input_value("xxx", def_units="deg")
def summ_print(self):
# give Units object the current locals()/vars()
self.my_io.set_vars_dict(vars(self))
self.my_io.set_print_template(template="%12s = %-45s | %s")
print()
u_print = self.my_io.u_print
u_print("x", "area of interest")
u_print("x")
u_print("x", "area of interest", "inch**2", added_units="cm**2")
print()
u_print("xxx", desc="Angle of interest")
u_print("xxx", primary_units="rad", desc="Angle of interest")
u_print("xxx", "Angle of interest", "rad", "circle")
print()
u_print("y", desc="Time of flight", added_units="hr")
u_print("j", desc="Just a Number")
def distance(vinit="10.0 m/s",
acc="9.80665 m/s**2",
time="30 s",
output_units="SI"):
"""
Calculate the distance traveled by an object with some initial velocity,
and a constant acceleration over a given time.
Note that any units available in RocketUnits may be used
as inputs for vinit, acc and time.
Args:
vinit (float): Initial velocity, m/s
acc (float): Acceleration(standard gravity=9.80665), m/s**2
time (float): Time, s
Returns:
float: Distance traveled, m
"""
# let Units inspect the distance interface and get locals() values
my_units = Units(distance, vars())
# let Units convert inputs into internal units
vinit = my_units.get_input_value("vinit")
acc = my_units.get_input_value("acc")
time = my_units.get_input_value("time")
# If using Units for output, tell Units the internal units for "d"
my_units.set_units("d", "m")
d = vinit * time + acc * time**2 / 2.0 # do the calculation with internal units
# give local variable values to Units
my_units.set_vars_dict(vars())
# set a desired output template
my_units.set_print_template(template="%8s = %-40s %s")
# make a convenience copy of my_units.u_print
u_print = my_units.u_print
u_print("vinit", "Initial velocity") # optional , fmt="%g"
u_print("acc", "Acceleration")
u_print("time", "Time")
u_print("d", primary_units="km", added_units="yd")
return d
class RocketDeltaV:
gc = 32.174 # gravitational converstion factor lbm-ft/lbf-sec**2
def __init__(self,
Isp="330.0 sec",
mass="10000.0 lbm",
prop_mass_frac=0.8):
"""
Calculate the ideal rocket velocity based on the percent of propellant burned.
(see: https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation)
(or: https://www.translatorscafe.com/unit-converter/en-US/calculator/rocket-equation/)
Args:
Isp (float): specific impulse, sec (https://en.wikipedia.org/wiki/Specific_impulse)
mass (float): total rocket mass, lbm
prop_mass_frac (float): mass fraction of rocket that is propellant
"""
# let Units inspect the class interface and get locals() values
self.my_io = Units(self.__class__, locals())
# let Units convert inputs into internal units (sec and lbm)
self.Isp = self.my_io.get_input_value("Isp")
self.mass = self.my_io.get_input_value("mass")
self.prop_mass_frac = prop_mass_frac # note: mass fraction is unitless
def summarize_delta_v(self, pcent_burned=100.0, output_units="Both"):
"""
Assuming a given percentage of the propellant is burned,
calculate the ideal change in velocity, ft/sec
Print a summary of the calculation.
Args:
pcent_burned (float): percent of propellant burned
Returns:
delta_v (float): ideal rocket velocity, ft/s
"""
if pcent_burned < 0.0 or pcent_burned > 100.0:
raise Exception("pcent_burned must be >=0 and <=100")
self.pcent_burned = pcent_burned
self.prop_mass = (pcent_burned /
100.0) * self.prop_mass_frac * self.mass
self.final_mass = self.mass - self.prop_mass
self.delta_v = self.gc * self.Isp * log(self.mass / self.final_mass)
# give Units object the current locals()/vars()
self.my_io.set_output_units(output_units=output_units)
self.my_io.set_vars_dict(vars(self))
self.my_io.set_print_template(template="%16s = %-45s %s")
self.my_io.set_units('prop_mass', 'lbm')
self.my_io.set_units('pcent_burned', '')
self.my_io.set_units('final_mass', 'lbm')
self.my_io.set_units('delta_v', 'ft/s')
# make a convenience copy of my_units.u_print
u_print = self.my_io.u_print
# lazy way to iterate over object parameters known to Units.
for name in self.my_io.default_unitsD.keys():
u_print(name)
u_print("delta_v", primary_units="km/hr", added_units="mile/hr")
print()