PYTHON: Level 1 HPR (high powered rocketry) simulator

import numpy as np

import matplotlib.pyplot as plt

#variable in SI units

Mass = 1 # this is the weight of the rocket in kg

Dmass = 0.800 # this is the dry mass of the rocket ( mass without propellant)

Burntime = 3.5 #F15-4 rocket motor burn time

Timpulse = 49.61 # this is the total impulse of the F15-4 motor

Propmass = 0.065 # this is the actual mass of just the propellant

# defines the array that solves the area under the curve

def integrateGraph (time, array):

resArray = [0]

for n in range(0, len(time)-1):

resArray.append(resArray[-1]+0.5 *(array[n+1] + array[n])*(time[n+1]-time[n]))

return np.array(resArray)

#basic calculations to find thrust and mass flow rate

avgthrust = Timpulse/Burntime

mdot = Propmass/Burntime

# make a time array to later graph

time= np.linspace(0,10,100,False) # linspace is an array of numbes from 0-9.9

#phyiscs and integration method, its finding the area under the curve

index = int(np.where(time==Burntime)[0]+1)

thrust = np.append(np.repeat(avgthrust, index), np.repeat(0, len(time)-index))

mass= np.append(np.repeat(Mass, index) - time[0:index] * mdot, np.repeat(Dmass, len(time) - index))

acceleration = thrust/mass - 9.81

velocity = integrateGraph(time, acceleration)

displacement = integrateGraph(time, velocity)

plt.plot(time, displacement)

plt.plot(time, velocity)

plt.legend(["Displacement", "Velocity"])

plt.xlabel("Time")

plt.show()