def calculate_eos_roots(self, fluid_type=None):
A_mix = self.a_mix
B_mix = self.b_mix
p0 = 1.0
p1 = -1.0
p2 = A_mix - B_mix - (B_mix ** 2)
p3 = -(A_mix * B_mix)
if fluid_type is None:
return calculate_roots_of_cubic_equation(p0, p1, p2, p3)
else:
return find_correct_root_of_cubic_eos(p0, p1, p2, p3, fluid_type)
def calculate_eos_roots(self, fluid_type=None):
A_mix = self.a_mix
B_mix = self.b_mix
p0 = 1.0
p1 = - (B_mix + 1.0)
p2 = A_mix
p3 = - A_mix * B_mix
if fluid_type is None:
return calculate_roots_of_cubic_equation(p0, p1, p2, p3)
else:
return find_correct_root_of_cubic_eos(p0, p1, p2, p3, fluid_type)
def calculate_eos_roots(self, fluid_type=None):
A_mix = self.a_mix
B_mix = self.b_mix
p0 = 1.0
p1 = - (1.0 - B_mix)
p2 = A_mix - 3.0 * (B_mix ** 2) - 2.0 * B_mix
p3 = -(A_mix * B_mix - B_mix ** 2 - B_mix ** 3)
if fluid_type is None:
return calculate_roots_of_cubic_equation(p0, p1, p2, p3)
else:
return find_correct_root_of_cubic_eos(p0, p1, p2, p3, fluid_type)
def find_correct_root_of_cubic_eos(p0, p1, p2, p3, fluid_type):
roots = calculate_roots_of_cubic_equation(p0, p1, p2, p3)
if len(roots) > 1:
assert len(roots) == 3, 'Size of roots has to be 1 or 3!'
roots.sort()
if fluid_type is 'liquid':
correct_root = roots[0] # smallest
else:
assert fluid_type is 'vapor', 'Wrong fluid type! ' + fluid_type
correct_root = roots[2] # largest
else:
correct_root = roots[0]
assert correct_root > 0.0, fluid_type + ' Z-factor < 0.0! %f' % correct_root
return correct_root
def find_correct_root_of_cubic_eos(p0, p1, p2, p3, fluid_type):
roots = calculate_roots_of_cubic_equation(p0, p1, p2, p3)
if len(roots) > 1:
assert len(roots) == 3, 'Size of roots has to be 1 or 3!'
roots.sort()
if fluid_type is 'liquid':
correct_root = roots[0] # smallest
else:
assert fluid_type is 'vapor', 'Wrong fluid type! ' + fluid_type
correct_root = roots[2] # largest
else:
correct_root = roots[0]
assert correct_root > 0.0, fluid_type + ' Z-factor < 0.0! %f' % correct_root
return correct_root