propellant-selector/propellant.py at master · cuspaceflight/propellant-selector · GitHub

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"""
Defines the Propellant class, used throughout the program
"""
from numpy import poly1d

from nist_reader import propellant_data, combo_data
from phase import Phase

oxidisers_phases = {
    "nitrous": [Phase.TWO_PHASE,  44],
}
fuels_phases = {
    "ammonia": [Phase.TWO_PHASE,  17],
    "ethane":  [Phase.TWO_PHASE,  30],
    "ethanol": [Phase.LIQUID,     46],
    "diesel":  [Phase.LIQUID,    166],
}


class Propellant(object):
    def __init__(self, phase):
        self.phase = phase
        self.F_density_liquid = None
        self.F_density_vapour = None
        self.F_pressure = None

    def pressure(self, temperature):
        if type(self.F_pressure) == poly1d:
            return(self.F_pressure(temperature))
        else:
            if self.phase == Phase.LIQUID:
                return(0)

    def liquid_density(self, temperature):
        if type(self.F_pressure) == poly1d:
            return(self.F_density_liquid(temperature))
        else:
            if self.phase == Phase.GAS:
                return(0)

    def vapor_density(self, temperature):
        if type(self.F_pressure) == poly1d and self.phase != Phase.LIQUID:
            return(self.F_density_vapour(temperature))
        else:
            if self.phase == Phase.LIQUID:
                return(0)


class Propellant_Mix(object):
    def __init__(self, fuel, oxidiser, temperature, pressure):
        if not (fuel in fuels_phases.keys()):
            return ValueError("Fuel not defined")
        else:
            self.fuel = Propellant(fuels_phases[fuel][0])
            self.fuel_name = fuel

        if not oxidiser in oxidisers_phases.keys():
            return ValueError("Oxidiser not defined")
        else:
            self.oxidiser = Propellant(oxidisers_phases[oxidiser][0])
            self.oxidiser_name = oxidiser

        combo_data(self, "combos")

        propellant_data(self.fuel, fuel)
        propellant_data(self.oxidiser, oxidiser)

        self.temperature = temperature
        self.pressure = pressure

        self.OF_mass_ratio = self.OF_molar_ratio * \
            oxidisers_phases[oxidiser][1] / fuels_phases[fuel][1]

        if self.fuel.pressure(self.temperature) > self.pressure:
            print("Fuel will self-pressurise to greater than specified pressure")
            input("Input any value to increase pressure to fuel vapour pressure  ")
            if input != "":
                self.pressure = self.fuel.pressure(self.temperature)

        if self.oxidiser.pressure(self.temperature) > self.pressure:
            print("Oxidiser will self-pressurise to greater than specified pressure")
            input("Input any value to increase pressure to oxidiser vapour pressure  ")
            if input != "":
                self.pressure = self.oxidiser.pressure(self.temperature)

        if self.pressure != pressure:
            print("New pressure is "+str(round(self.pressure, 2))+" bar")


class Pressurant(object):
    def __init__(self, name, molar_mass, R):
        self.name = name
        self.molar_mass = molar_mass
        self.R = R