def Volume_solve(T, P_bar, Pc_bar, Tc, m):
Pc = Pc_bar * 100
P = P_bar * 100
calc = Psat.Psat(T, Tc, Pc_bar, m)
P_sat_bar = calc[0]
P_sat = P_sat_bar * 100
a_eq = Psat.a(T, Tc, Pc, m)
b_eq = (R * Tc) / (8 * Pc)
def V_root(V):
return Psat.vdw(T, a_eq, b_eq, V, 0) - P
if P > P_sat:
V_guess = calc[1] * 0.95
V_root = sc_o.fsolve(V_root, V_guess)
return [V_root[0], 0]
elif P < P_sat:
V_guess = calc[2] * 1.05
V_root = sc_o.fsolve(V_root, V_guess)
return [0, V_root[0]]
else:
return [calc[1], calc[2]]
def vdw_residual(params, x, data):
T = params['T'].value
m = params['m'].value
Tc = params['Tc'].value
Pc = params['Pc'].value
x_range = numpy.size(x, axis=0)
model_data = numpy.zeros(x_range)
for k in range(x_range):
calc = Psat.Psat(x[k], Tc, Pc, m)
model_data[k] = calc[0]*100
return (model_data-data)/abs(model_data)
def V_single(T, Tc, P_bar, Pc_bar, m):
Pc = Pc_bar*100
P = P_bar*100
calc = Psat.Psat(T, Tc, Pc_bar, m)
sat_P = calc[0]*100
a_eq = Psat.a(T, Tc, Pc, m)
b = (R*Tc)/(8*Pc)
def eq(V):
return abs(Psat.vdw(T, a_eq, b, V, 0) - P)
if P > sat_P:
V_id_l = sc_o.fsolve(eq, [0.99*calc[1]])
return [V_id_l]
elif P < sat_P:
V_id_v = sc_o.fsolve(eq, [1.01*calc[2]])
return [V_id_v]
else:
V_id_l = calc[1]
V_id_v = calc[2]
return [V_id_l, V_id_v]
def calculate_and_plot(self, event):
self.T_slider_label.SetLabel('Isotherm Temperature = ' +
str(self.T_slider.GetValue()) + ' K')
Tc = 0
Pc = 0
m = 0
T = float(self.T_slider.GetValue())
T_Text = str(self.T_slider.GetValue())
Tc_text = self.Tc_input.GetValue()
Pc_text = self.Pc_input.GetValue()
m_text = self.m_input.GetValue()
if (Tc_text != '') and (Pc_text != '') and (m_text != ''):
Tc = float(Tc_text)
Pc = float(Pc_text) * 100
m = float(m_text)
# Bereken aCrit
if (Tc != 0) and (Pc != 0) and (m != 0):
R = Psat.R
ac = (27 * R * R * Tc * Tc) / (64 * Pc)
b = (R * Tc) / (8 * Pc)
calc = Psat.Psat(T, Tc, Pc / 100, m)
Psatval = calc[0]
self.ac_label = str(round(ac, 4))
self.b_label = str(round(b, 4))
if np.isreal(Psatval):
self.Psat_label = str(round(Psatval, 4))
else:
self.Psat_label = Psatval
self.ac_val.SetLabel('ac = ' + self.ac_label)
self.b_val.SetLabel('b = ' + self.b_label)
self.m_val.SetLabel('m = ' + m_text)
self.P_sat.SetLabel('Psat = ' + self.Psat_label)
#Calculate datapoints for vdw EOS
Data = np.zeros((1001))
Line_Data = np.zeros((1001))
for k in range(0, 1001):
Data[k] = 100000 * ((0.1**(10 - 0.01 * k))) + b + 0.01
Value = max([
min([
Psat.vdw(T, Psat.a(T, Tc, Pc, m), b, Data[k], 0) / 100,
100
]), -1000
])
V_l = calc[1]
V_v = calc[2]
if Data[k] < V_l or Data[k] > V_v:
Line_Data[k] = Value
else:
Line_Data[k] = Psatval
Plot_Data1 = np.vstack((Data, Line_Data)).T
Isotherm = PolyLine(Plot_Data1,
legend='Isotherm, T = ' + T_Text,
colour='blue')
self.canvas.Draw(PlotGraphics([Isotherm], '', ' V', 'P'))
self.canvas.setLogScale((True, False))
