def end_burn(a, density, c_star, gamma, n, exit_mach, exit_velocity, exit_area, throat_area, dt, motor_height,
motor_diameter):
# initialize loop variables
regression_depth = 0
elapsed_time = 0 # start the burn at zero seconds
count = 0
# initialize output lists
chamber_pressure_list = np.array([0])
burn_rate_list = np.array([0])
regression_depth_list = np.array([0])
burning_area_list = np.array([0])
m_dot_list = np.array([0])
exit_pressure_list = np.array([0])
thrust_list = np.array([0])
elapsed_time_list = np.array([0])
burning_area = geometry.circle_area(motor_diameter)
sim_start = time.time()
burning = True
while burning:
count = count + 1
# iterate calculations
chamber_pressure = burn.calculate_chamber_pressure(burning_area, throat_area, a, density, c_star, n)
burn_rate = burn.calculate_burn_rate(a, chamber_pressure, n)
regression_depth = burn.calculate_new_regression_dist(regression_depth, burn_rate, dt)
m_dot = burn.calculate_mass_flow_rate(burning_area, burn_rate, density)
exit_pressure = burn.calculate_nozzle_exit_pressure(chamber_pressure, gamma, exit_mach)
thrust = burn.calculate_vacuum_thrust(m_dot, exit_velocity, exit_area, exit_pressure)
elapsed_time = elapsed_time + dt
# record values
chamber_pressure_list = np.append(chamber_pressure_list, chamber_pressure)
burn_rate_list = np.append(burn_rate_list, burn_rate)
regression_depth_list = np.append(regression_depth_list, regression_depth)
burning_area_list = np.append(burning_area_list, burning_area)
m_dot_list = np.append(m_dot_list, m_dot)
exit_pressure_list = np.append(exit_pressure_list, exit_pressure)
elapsed_time_list = np.append(elapsed_time_list, elapsed_time)
thrust_list = np.append(thrust_list, thrust)
# available exits
if regression_depth >= motor_height:
burning = False
# print("'successful' burn out")
if count >= 100000:
burning = False
print("unsuccessful burn out, 1000 iteration criteria violated")
if time.time() - sim_start > 30:
print("unsuccessful burn out, 30 second criteria violated")
burning = False
return chamber_pressure_list, burn_rate_list, regression_depth_list, burning_area_list, m_dot_list, exit_pressure_list, elapsed_time_list, thrust_list
def burn_motor(regression_map, throat_area, a, density, c_star, gamma, n,
exit_mach, exit_velocity, exit_area, dt, mc_mask, volume_ratio):
elapsed_time = 0 # start the burn at zero seconds
regression_depth = 0.00001 # m
thrust_initial = 10
count = 0
chamber_pressure_list = np.array([0])
burn_rate_list = np.array([0])
regression_depth_list = np.array([0])
burning_area_list = np.array([0])
m_dot_list = np.array([0])
exit_pressure_list = np.array([0])
thrust_list = np.array([0])
elapsed_time_list = np.array([0])
burning = True
burning_area = calculate_burning_area(regression_map, -0.001, mc_mask,
volume_ratio)
sim_start = time.time()
while burning:
count = count + 1
chamber_pressure = burn.calculate_chamber_pressure(
burning_area, throat_area, a, density, c_star, n) # obsolete
burn_rate = burn.calculate_burn_rate(a, chamber_pressure, n)
regression_depth = burn.calculate_new_regression_dist(
regression_depth, burn_rate, dt)
burning_area = calculate_burning_area(regression_map,
-regression_depth, mc_mask,
volume_ratio)
m_dot = burn.calculate_mass_flow_rate(burning_area, burn_rate, density)
exit_pressure = burn.calculate_nozzle_exit_pressure(
chamber_pressure, gamma, exit_mach)
thrust = burn.calculate_vacuum_thrust(m_dot, exit_velocity, exit_area,
exit_pressure)
elapsed_time = elapsed_time + dt
if count == 1:
thrust_initial = thrust
chamber_pressure_list = np.append(chamber_pressure_list,
chamber_pressure)
burn_rate_list = np.append(burn_rate_list, burn_rate)
regression_depth_list = np.append(regression_depth_list,
regression_depth)
burning_area_list = np.append(burning_area_list, burning_area)
m_dot_list = np.append(m_dot_list, m_dot)
exit_pressure_list = np.append(exit_pressure_list, exit_pressure)
elapsed_time_list = np.append(elapsed_time_list, elapsed_time)
thrust_list = np.append(thrust_list, thrust)
if thrust < thrust_initial * 0.1:
burning = False
if count >= 1000:
burning = False
if time.time() - sim_start > 60:
burning = False
return chamber_pressure_list, burn_rate_list, regression_depth_list, burning_area_list, m_dot_list, exit_pressure_list, elapsed_time_list, thrust_list
def bates_burn_motor(throat_area, a, density, c_star, gamma, n, exit_mach, exit_velocity, exit_area, dt, motor_height,
motor_diameter, core_diameter, burn_top, burn_bottom):
regression_depth = 0
elapsed_time = 0 # start the burn at zero seconds
count = 0
chamber_pressure_list = np.array([0])
burn_rate_list = np.array([0])
regression_depth_list = np.array([0])
burning_area_list = np.array([0])
m_dot_list = np.array([0])
exit_pressure_list = np.array([0])
thrust_list = np.array([0])
elapsed_time_list = np.array([0])
burning = True
burning_area = bates_burn_area(regression_depth, core_diameter, motor_height, motor_diameter, burn_top, burn_bottom)
sim_start = time.time()
while burning:
count = count + 1
# calculate iterations
chamber_pressure = burn.calculate_chamber_pressure(burning_area, throat_area, a, density, c_star, n) # obsolete
burn_rate = burn.calculate_burn_rate(a, chamber_pressure, n)
regression_depth = burn.calculate_new_regression_dist(regression_depth, burn_rate, dt)
burning_area = bates_burn_area(regression_depth, core_diameter, motor_height, motor_diameter, burn_top, burn_bottom)
m_dot = burn.calculate_mass_flow_rate(burning_area, burn_rate, density)
exit_pressure = burn.calculate_nozzle_exit_pressure(chamber_pressure, gamma, exit_mach)
thrust = burn.calculate_vacuum_thrust(m_dot, exit_velocity, exit_area, exit_pressure)
elapsed_time = elapsed_time + dt
# record values
chamber_pressure_list = np.append(chamber_pressure_list, chamber_pressure)
burn_rate_list = np.append(burn_rate_list, burn_rate)
regression_depth_list = np.append(regression_depth_list, regression_depth)
burning_area_list = np.append(burning_area_list, burning_area)
m_dot_list = np.append(m_dot_list, m_dot)
exit_pressure_list = np.append(exit_pressure_list, exit_pressure)
elapsed_time_list = np.append(elapsed_time_list, elapsed_time)
thrust_list = np.append(thrust_list, thrust)
if regression_depth * 2 + core_diameter > motor_diameter:
burning = False
# print("'successful' burn out")
if count >= 1000:
burning = False
print("unsuccessful burn out, 1000 iteration criteria violated")
if time.time()-sim_start > 60:
print("unsuccessful burn out, 60 second criteria violated")
burning = False
return chamber_pressure_list, burn_rate_list, regression_depth_list, burning_area_list, m_dot_list, exit_pressure_list, elapsed_time_list, thrust_list
def wagon_wheel_burn(Ro, Rp, Ri, f, N, epsilon, theta, a, density, c_star, gamma, n, exit_mach, exit_velocity,
exit_area, dt, motor_height, motor_diameter, throat_area, burn_top, burn_bottom):
# initialize loop variables
regression_depth = 0
elapsed_time = 0 # start the burn at zero seconds
count = 0
# initialize output lists
chamber_pressure_list = np.array([0])
burn_rate_list = np.array([0])
regression_depth_list = np.array([0])
burning_area_list = np.array([0])
m_dot_list = np.array([0])
exit_pressure_list = np.array([0])
thrust_list = np.array([0])
elapsed_time_list = np.array([0])
# calculate zero contour burn area
burning_area = wagon_wheel_burn_area(motor_height, motor_diameter, Ro, Rp, Ri, f, N, epsilon, theta,
regression_depth, burn_top, burn_bottom)
sim_start = time.time()
burning = True
while burning:
count = count + 1
# iterate calculations
chamber_pressure = burn.calculate_chamber_pressure(burning_area, throat_area, a, density, c_star, n) # obsolete
burn_rate = burn.calculate_burn_rate(a, chamber_pressure, n)
regression_depth = burn.calculate_new_regression_dist(regression_depth, burn_rate, dt)
burning_area = wagon_wheel_burn_area(motor_height, motor_diameter, Ro, Rp, Ri, f, N, epsilon, theta,
regression_depth, burn_top, burn_bottom)
m_dot = burn.calculate_mass_flow_rate(burning_area, burn_rate, density)
exit_pressure = burn.calculate_nozzle_exit_pressure(chamber_pressure, gamma, exit_mach)
thrust = burn.calculate_vacuum_thrust(m_dot, exit_velocity, exit_area, exit_pressure)
elapsed_time = elapsed_time + dt
# record values
chamber_pressure_list = np.append(chamber_pressure_list, chamber_pressure)
burn_rate_list = np.append(burn_rate_list, burn_rate)
regression_depth_list = np.append(regression_depth_list, regression_depth)
burning_area_list = np.append(burning_area_list, burning_area)
m_dot_list = np.append(m_dot_list, m_dot)
exit_pressure_list = np.append(exit_pressure_list, exit_pressure)
elapsed_time_list = np.append(elapsed_time_list, elapsed_time)
thrust_list = np.append(thrust_list, thrust)
# available exits
if (regression_depth + Ri + f) > motor_diameter:
burning = False
# print("'successful' burn out")
if thrust <= 0:
burning = False
if count >= 1000:
burning = False
print("unsuccessful burn out, 1000 iteration criteria violated")
if time.time() - sim_start > 60:
print("unsuccessful burn out, 60 second criteria violated")
burning = False
return chamber_pressure_list, burn_rate_list, regression_depth_list, burning_area_list, m_dot_list,\
exit_pressure_list, elapsed_time_list, thrust_list
def star_burn(Ro, Rp, Ri, epsilon, N, f, a, density, c_star, gamma, n, exit_mach, exit_velocity, exit_area, dt, motor_height,
motor_diameter, throat_area, burn_top, burn_bottom):
# initialize loop variables
regression_depth = 0
elapsed_time = 0 # start the burn at zero seconds
count = 0
# initialize output lists
chamber_pressure_list = np.array([0])
burn_rate_list = np.array([0])
regression_depth_list = np.array([0])
burning_area_list = np.array([0])
m_dot_list = np.array([0])
exit_pressure_list = np.array([0])
thrust_list = np.array([0])
elapsed_time_list = np.array([0])
# determine theta parameter from inputs
theta = 2 * np.arctan(Rp * np.sin(np.pi * epsilon / N) * np.tan(np.pi * epsilon / N) /
(Rp * np.sin(np.pi * epsilon/ N) - Ri * np.tan(np.pi * epsilon / N)))
print(f"theta = {theta}")
# calculate zero contour burn area
burning_area = star_burn_area(motor_height, motor_diameter, Ro, Rp, Ri, epsilon, N, regression_depth, f, theta, burn_top, burn_bottom)
sim_start = time.time()
burning = True
while burning:
count = count + 1
# iterate calculations
chamber_pressure = burn.calculate_chamber_pressure(burning_area, throat_area, a, density, c_star, n) # obsolete
burn_rate = burn.calculate_burn_rate(a, chamber_pressure, n)
regression_depth = burn.calculate_new_regression_dist(regression_depth, burn_rate, dt)
burning_area = star_burn_area(motor_height, motor_diameter, Ro, Rp, Ri, epsilon, N, regression_depth, f, theta, burn_top, burn_bottom)
m_dot = burn.calculate_mass_flow_rate(burning_area, burn_rate, density)
exit_pressure = burn.calculate_nozzle_exit_pressure(chamber_pressure, gamma, exit_mach)
thrust = burn.calculate_vacuum_thrust(m_dot, exit_velocity, exit_area, exit_pressure)
elapsed_time = elapsed_time + dt
# record values
chamber_pressure_list = np.append(chamber_pressure_list, chamber_pressure)
burn_rate_list = np.append(burn_rate_list, burn_rate)
regression_depth_list = np.append(regression_depth_list, regression_depth)
burning_area_list = np.append(burning_area_list, burning_area)
m_dot_list = np.append(m_dot_list, m_dot)
exit_pressure_list = np.append(exit_pressure_list, exit_pressure)
elapsed_time_list = np.append(elapsed_time_list, elapsed_time)
thrust_list = np.append(thrust_list, thrust)
# print values
print(f"\nIteration: {count}")
print(f"Time: {round(elapsed_time, 3)} sec")
print(f"Regression: {round(regression_depth, 3)} m")
print(f"Burning Area: {round(burning_area, 3)} m^2")
print(f"Pressure: {round(chamber_pressure, 3)} Pa")
print(f"Burn Rate: {round(burn_rate, 3)} m/sec")
print(f"Mass Flow Rate: {round(m_dot, 3) } kg/sec")
print(f"Exit Pressure: {round(exit_pressure, 3)} Pa")
print(f"Thrust: {round(thrust, 3)} N")
# available exits
if regression_depth + f + Ri > motor_diameter:
burning = False
# print("'successful' burn out")
if count >= 1000:
burning = False
print("unsuccessful burn out, 1000 iteration criteria violated")
if time.time() - sim_start > 60:
print("unsuccessful burn out, 60 second criteria violated")
burning = False
if thrust == 0:
burning = False
return chamber_pressure_list, burn_rate_list, regression_depth_list, burning_area_list, m_dot_list, exit_pressure_list, elapsed_time_list, thrust_list
def burn_motor(regression_map, throat_area, a, density, c_star, gamma, n,
exit_mach, exit_velocity, exit_area, dt, map_ratio,
motor_height, core_diameter, motor_diameter, fidelity):
elapsed_time = 0 # start the burn at zero seconds
regression_depth = 0.0000001 # m
max_regression = (motor_diameter - core_diameter) / 2
thrust_initial = True
count = 0
chamber_pressure_list = np.array([0])
burn_rate_list = np.array([0])
regression_depth_list = np.array([0])
burning_area_list = np.array([0])
m_dot_list = np.array([0])
exit_pressure_list = np.array([0])
thrust_list = np.array([0])
elapsed_time_list = np.array([0])
burning = True
burning_area = calculate_burning_area(regression_map, regression_depth,
motor_height, map_ratio, fidelity)
sim_start = time.time()
while burning:
count = count + 1
# calculate values
chamber_pressure = burn.calculate_chamber_pressure(
burning_area, throat_area, a, density, c_star, n) # obsolete
burn_rate = burn.calculate_burn_rate(a, chamber_pressure, n)
regression_depth = burn.calculate_new_regression_dist(
regression_depth, burn_rate, dt)
burning_area = calculate_burning_area(regression_map, regression_depth,
motor_height, map_ratio,
fidelity)
m_dot = burn.calculate_mass_flow_rate(burning_area, burn_rate, density)
exit_pressure = burn.calculate_nozzle_exit_pressure(
chamber_pressure, gamma, exit_mach)
thrust = burn.calculate_vacuum_thrust(m_dot, exit_velocity, exit_area,
exit_pressure)
elapsed_time = elapsed_time + dt
if count == 1:
thrust_initial = thrust
if thrust < thrust_initial * 0.1:
burning = False
if count >= 1000:
burning = False
print("2d sim took too many iterations")
if time.time() - sim_start > 30:
burning = False
print("2d sim took too long")
if regression_depth > max_regression:
burning = False
print(f"2d regression distance exceeded max of: {max_regression}")
# record values
chamber_pressure_list = np.append(chamber_pressure_list,
chamber_pressure)
burn_rate_list = np.append(burn_rate_list, burn_rate)
regression_depth_list = np.append(regression_depth_list,
regression_depth)
burning_area_list = np.append(burning_area_list, burning_area)
m_dot_list = np.append(m_dot_list, m_dot)
exit_pressure_list = np.append(exit_pressure_list, exit_pressure)
elapsed_time_list = np.append(elapsed_time_list, elapsed_time)
thrust_list = np.append(thrust_list, thrust)
return chamber_pressure_list, burn_rate_list, regression_depth_list, burning_area_list, m_dot_list, exit_pressure_list, elapsed_time_list, thrust_list