def test_greater_cd(self):
'增大c_d的线性系数，应当使得phi减小'
solver1 = const.ConstantSolver()
solver1.set_constants(0.2, 1, 1.225, 5)
solver1.set_c_d(util.SampleFunction([(0, 0.5), (math.pi / 2, 0.5)]))
solver1.set_c_l(
util.SampleFunction([(0, 0), (math.pi / 2, 4 * math.pi / 2)]))
delta = 0.001
phi1 = solver1.solve(delta=delta)
solver2 = const.ConstantSolver()
solver2.set_constants(0.2, 1, 1.225, 5)
solver2.set_c_d(util.SampleFunction([(0, 1),
(math.pi / 2, 1)])) #增大了c_d常量
solver2.set_c_l(
util.SampleFunction([(0, 0), (math.pi / 2, 4 * math.pi / 2)]))
delta = 0.001
phi2 = solver2.solve(delta=delta)
self.assertLess(phi2, phi1, "phi should be less when c_d increases")
def test_greater_cl(self):
'增大c_l的线性系数，应当使得phi增大'
solver1 = const.ConstantSolver()
solver1.set_constants(0.2, 1, 1.225, 5)
solver1.set_c_d(util.SampleFunction([(0, 0.5), (math.pi / 2, 0.5)]))
solver1.set_c_l(
util.SampleFunction([(0, 0), (math.pi / 2, 4 * math.pi / 2)]))
delta = 0.001
phi1 = solver1.solve(delta=delta)
solver2 = const.ConstantSolver()
solver2.set_constants(0.2, 1, 1.225, 5)
solver2.set_c_d(util.SampleFunction([(0, 0.5), (math.pi / 2, 0.5)]))
solver2.set_c_l(
util.SampleFunction([(0, 0), (math.pi / 2, 5 * math.pi / 2)]))
delta = 0.001
phi2 = solver2.solve(delta=delta)
self.assertGreater(phi2, phi1,
"phi should be greater when c_l increases")
def test_right_solution(self):
'求解器得到的结果调用compute方法应该误差在delta内'
solver = const.ConstantSolver()
solver.set_constants(0.2, 1, 1.225, 5)
solver.set_c_d(util.SampleFunction([(0, 0.5), (math.pi / 2, 0.5)]))
solver.set_c_l(
util.SampleFunction([(0, 0), (math.pi / 2, 5 * math.pi / 2)]))
delta = 0.0001
phi = solver.solve(delta=delta)
self.assertLessEqual(solver.compute(phi), delta,
"solution's function value too big")
def test_strong_wind(self):
'当风力非常大的时候phi应当与风速无关，只要c_l / c_d 近似等于 tan(phi)即可'
solver1 = const.ConstantSolver()
solver1.set_constants(0.2, 1, 1.225, 10000)
solver1.set_c_d(util.SampleFunction([(0, 0.5), (math.pi / 2, 0.5)]))
solver1.set_c_l(
util.SampleFunction([(0, 0), (math.pi / 2, 5 * math.pi / 2)]))
delta = 0.001
phi1 = solver1.solve(delta=delta)
solver2 = const.ConstantSolver()
solver2.set_constants(0.2, 1, 1.225, 60000)
solver2.set_c_d(util.SampleFunction([(0, 0.5), (math.pi / 2, 0.5)]))
solver2.set_c_l(
util.SampleFunction([(0, 0), (math.pi / 2, 5 * math.pi / 2)]))
delta = 0.001
phi2 = solver2.solve(delta=delta)
self.assertLessEqual(abs(math.tan(phi1) - math.tan(phi2)), 3 * delta,
"not constant under strong wind")
ydata = []
line, = ax.plot(xdata, ydata, 'r-')
solver = dynamic.DynamicSolver()
alpha = 0
dic_para = {
'mass':0.05,
'density':1.225,
'area':1,
'c_d':DemoDragFunction(),
'c_l':DemoLiftFunction(),
'v_wind':(-5, 0),
}
solver.init(
mass=dic_para['mass'], density=dic_para['density'], area=dic_para['area'],
c_d=dic_para['c_d'],c_l=dic_para['c_l'],
v_wind=dic_para['v_wind'], v_vertical_0=2, r_0=(-10* math.cos(alpha), 10 * math.sin(alpha)),
reader=reader.VReaderSteady()
)
const_solver = const.ConstantSolver()
const_solver.set_constants(mass=dic_para['mass'],
area=dic_para['area'],
density=dic_para['density'],
v_wind=abs(dic_para['v_wind'][0]))
const_solver.set_c_d(dic_para['c_d'])
const_solver.set_c_l(dic_para['c_l'])
res = const_solver.solve()
print(math.tan(res))
line_ani = animation.FuncAnimation(fig, update_line, 1000, fargs=(xdata, ydata, solver, line, ax), interval=50)
plt.show()