138 lines
4.0 KiB
Python
138 lines
4.0 KiB
Python
from matplotlib import pyplot as plot
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import numpy as np
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temperatures = []
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# Standard-Atmosphärendruck [Pa]
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g_p0 = 101325
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# spezifischen Gaskonstante R_S = R/M = 287,058 J/(kg*K) für trockene Luft
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g_RS = 287.54
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# CW-Wert und Stirnfläche
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car_list = {
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'VW id.3' : {'cw': 0.267, 'area': 2.36},
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'Tesla Model Y LR AWD': {'cw': 0.23, 'area': 2.518},
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'Tesla Model 3 LR AWD': {'cw': 0.23, 'area': 2.220},
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'Polestar 2': {'cw': 0.278, 'area': 2.480},
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'Renault Zoe': {'cw': 0.33, 'area': 2.27},
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'Hyundai Kona Elektro': {'cw': 0.29, 'area': 2.37},
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'Hyundai Ioniq': {'cw': 0.24, 'area': 2.22}
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}
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temp_list = [-20, -10, 0, 10, 20, 30]
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vel_list = [20, 40, 60, 80, 100, 120, 130, 140, 160]
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# rho: [kg/m3]
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def rho(temperature_degc: float, p_pa: float =g_p0):
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return p_pa/(g_RS*(temperature_degc + 273.15))
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# Force : N = kg·m·s2
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def fd(rho: float, velocity_kmh: float, c_val: float, area: float):
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vel = velocity_kmh / 3.6
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cwa = c_val * area
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res = 0.5*rho*vel*vel*cwa
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return res
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def plot_1(car_ref, t_ref=20, v_ref=100):
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fd_reference_100 = fd(rho(t_ref), v_ref, car_ref['cw'], car_ref['area'])
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temps_list_leg = [f"{t}°C" for t in temp_list]
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plot.figure()
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for temp_degc in temp_list:
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rho_t = rho(temp_degc)
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y_fd = []
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for vel_kmh in vel_list:
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fd_t = (fd(rho_t, vel_kmh, car_ref['cw'], car_ref['area'])/fd_reference_100 - 1) * 100
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y_fd.append(fd_t)
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plot.plot(vel_list, y_fd)
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plot.title(f"Luftwiderstand vs Geschwindigkeit, T={t_ref}°C, v={v_ref}km/h")
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plot.ylabel("Luftwiderstand [%]")
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plot.xlabel("Geschwindigkeit [km/h]")
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plot.legend(temps_list_leg)
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plot.grid()
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def plot_2(car_ref, t_ref=20, v_ref=100):
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''' Fd vs. velocity, param: car '''
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# [kmh]
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car_list_leg = [f"{t}" for t in car_list.keys()]
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rho_t = rho(t_ref)
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reference = fd(rho_t, v_ref, car_ref['cw'], car_ref['area'])
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plot.figure()
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for key in car_list:
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car = car_list[key]
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y_fd = []
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for vel_kmh in vel_list:
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fd_t = (fd(rho_t, vel_kmh, car['cw'], car['area'])/reference - 1) * 100
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y_fd.append(fd_t)
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plot.plot(vel_list, y_fd)
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plot.ylabel("Luftwiderstand ID.3 [%]")
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plot.xlabel("Geschwindigkeit [km/h]")
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plot.title(f"Luftwiderstand vs Geschwindigkeit, T={t_ref}°C, v={v_ref}km/h")
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plot.legend(car_list_leg)
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plot.grid()
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def plot_3(y_fd, y_pwr, t_ref=20):
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car_list_leg = [f"{t}" for t in car_list.keys()]
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fig, ax1 = plot.subplots()
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ax1.plot(vel_list, y_fd)
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ax1.set_ylabel("Luftwiderstand [N]")
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ax1.set_xlabel("Geschwindigkeit [km/h]")
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ax1.set_title(f"Luftwiderstand vs Geschwindigkeit, T={t_ref}°C")
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ax1.legend(car_list_leg)
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ax2 = ax1.twinx()
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ax2.set_ylabel("Antriebsleistung [kW]", color='tab:red')
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ax2.plot(vel_list, y_pwr, color='tab:red')
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ax2.tick_params(axis='y', labelcolor='tab:red')
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ax1.grid()
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def plot_4(y_fd, y_energy, temp=20):
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car_list_leg = [f"{t}" for t in car_list.keys()]
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fig, ax1 = plot.subplots()
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ax1.plot(vel_list, y_fd)
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ax1.set_ylabel("Luftwiderstand [N]")
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ax1.set_xlabel("Geschwindigkeit [km/h]")
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ax1.set_title(f"Luftwiderstand vs Geschwindigkeit, Temperature {temp}°C")
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ax1.legend(car_list_leg)
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ax2 = ax1.twinx()
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ax2.set_ylabel("Antriebsenergie [kWh/100km]", color='tab:red')
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ax2.plot(vel_list, y_energy, color='tab:red')
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ax2.tick_params(axis='y', labelcolor='tab:red')
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ax1.grid()
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plot.show()
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def main() -> None:
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car = car_list['VW id.3']
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# Fd vs. velocity, param: temperature
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temp_ref = 20
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# Luftwiderstand [%] vs. Geschwindigkeit [kmh], Param: Temperatur
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plot_1(car)
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# Luftwiderstand [%] vs. Geschwindigkeit [kmh] at 20°C, Param: Car Model
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plot_2(car, temp_ref)
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y_fd = []
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y_pwr = []
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y_energy = []
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for vel_kmh in vel_list:
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fd_t = fd(rho(temp_ref), vel_kmh, car['cw'], car['area'])
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y_fd.append(fd_t)
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y_pwr.append(fd_t*vel_kmh/1000/3.6)
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y_energy.append(fd_t*vel_kmh/1000/3.6*100/vel_kmh)
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# Luftwiderstand [N] / Antriebsleistung [kW] vs. Geschwindigkeit [kmh], Param: Temp
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plot_3(y_fd, y_pwr, temp_ref)
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# Luftwiderstand [N] / Antriebsenergie [kWh/100km] vs. Geschwindigkeit [kmh], Param: Temp
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plot_4(y_fd, y_energy, temp_ref)
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if __name__ == '__main__':
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main()
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