Question

我必须在没有vpython的情况下计算2个身体重力系统（地球和月球）。

此代码的目的是练习数值计算，并且有我的代码。

import numpy as np
from math import *

from astropy.constants import *

import matplotlib.pyplot as plt

import time

start_time = time.time()

"""
G = Gravitational constant
g0 = Standard acceleration of gravity ( 9.8 m/s2)
M_sun = Solar mass
M_earth = Earth mass
R_sun = Solar darius
R_earth = Earth equatorial radius
au = Astronomical unit


"""

M_moon = 7.342E22
R_moon = 1.737E6
# Mean radius of moon.


M_earth = M_earth.value
R_earth = R_earth.value
G = G.value

perigee, apogee = 3.626E8, 4.054E8

position_E = np.array([0,0])
position_M = np.array([(perigee+apogee)/2.,0])
position_com = (M_earth*position_E+M_moon*position_M)/(M_earth+M_moon)

rel_pE = position_E - position_com
rel_pM = position_M - position_com


p_E = {"x":rel_pE[0], "y":rel_pE[1],"v_x":0, "v_y":10}
p_M = {"x":rel_pM[0], "y":rel_pM[1],"v_x":0, "v_y":-100}

t = range(0,365)

data_E , data_M = [0]*len(t), [0]*len(t)

def s(initial_velocity, acceleration, time):
    result = initial_velocity*time + 0.5*acceleration*time**2
    return result

def v(initial_velocity, acceleration, time):
    result = initial_velocity + acceleration*time
    return result

dist = float(sqrt((p_E["x"]-p_M['x'])**2 + (p_E["y"]-p_M["y"])**2))

# position data of Earth and Moon. make new list to make easy to draw plot

xE=[]
yE=[]
xM=[]
yM=[]

for i in t:
    dist = float(sqrt((p_E["x"]-p_M["x"])**2 + (p_E["y"]-p_M["y"])**2))


    a_Ex = -G*M_moon*p_E["x"]/(dist**2)
    a_Ey = -G*M_moon*p_E["y"]/(dist**2)

    data_E[i] = p_E

    p_E["x"] += s(p_E['v_x'], a_Ex, 24*3600)
    p_E["v_x"] += v(p_E['v_x'], a_Ex, 24*3600)
    p_E["y"] += s(p_E['v_y'], a_Ey, 24*3600)
    p_E["v_y"] += v(p_E['v_y'], a_Ey, 24*3600)

    xE += [p_E["x"]]
    yE += [p_E["y"]]

    a_Mx = -G*M_earth*p_M["x"]/(dist**2)
    a_My = -G*M_earth*p_M["y"]/(dist**2)

    data_M[i] = p_M

    p_M["x"] += s(p_M['v_x'], a_Mx, 24*3600)
    p_M["v_x"] += v(p_M['v_x'], a_Mx, 24*3600)
    p_M["y"] += s(p_M['v_y'], a_My, 24*3600)
    p_M["v_y"] += v(p_M['v_y'], a_My, 24*3600)

    xM += [p_M["x"]]
    yM += [p_M["y"]]

print("\n Run time \n --- %d seconds ---" %(time.time()-start_time))

但是这段代码会使x＆amp; y增加。

它没有显示椭圆轨道。如何修复我的代码或编写新的代码描述关于地球和地球的完美椭圆轨道？月球重力系统。

感谢您的帮助！

如何在没有vpython的数值模拟中解决python中的地球和月球轨道？

0 个答案: