def calculate_flap_moment(x, y, alpha, x_hinge, deflection,
unit_deflection = 'rad'):
"""For a given airfoil with coordinates x and y at angle of attack
alpha (degrees), calculate the moment coefficient around the joint at x_hinge
and deflection in radians (unit_deflection = 'rad') or degrees
(unit_deflection = 'deg')"""
# If x and y are not dictionaries with keys upper and lower, make them
# be so
if type(x) == list:
x, y = af.separate_upper_lower(x, y)
#Because parts of the program use keys 'u' and 'l', and other parts use
#'upper' and 'lower'
if 'u' in x.keys():
upper = {'x': x['u'], 'y': y['u']}
lower = {'x': x['l'], 'y': y['l']}
elif 'upper' in x.keys():
upper = {'x': x['upper'], 'y': y['upper']}
lower = {'x': x['lower'], 'y': y['lower']}
hinge = af.find_hinge(x_hinge, upper, lower)
if deflection > 0:
upper_static, upper_flap = af.find_flap(upper, hinge)
lower_static, lower_flap = af.find_flap(lower, hinge,
extra_points = 'lower')
elif deflection < 0:
upper_static, upper_flap = af.find_flap(upper, hinge,
extra_points = 'upper')
lower_static, lower_flap = af.find_flap(lower, hinge)
else:
upper_static, upper_flap = af.find_flap(upper, hinge,
extra_points = None)
lower_static, lower_flap = af.find_flap(lower, hinge,
extra_points = None)
upper_rotated, lower_rotated = af.rotate(upper_flap, lower_flap,
hinge, deflection,
unit_theta = unit_deflection)
flapped_airfoil, i_separator = af.clean(upper_static, upper_rotated, lower_static,
lower_rotated, hinge, deflection, N = None,
return_flap_i = True)
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#Third step: get new values of pressure coefficient
xf.create_input(x = flapped_airfoil['x'], y_u = flapped_airfoil['y'],
filename = 'flapped', different_x_upper_lower = True)
Data = xf.find_pressure_coefficients('flapped', alpha, NACA = False)
x, y, Cp = af.separate_upper_lower(x = Data['x'], y = Data['y'],
Cp = Data['Cp'], i_separator = i_separator)
#At the hinges, the reaction moment has the opposite sign of the
#actuated torque
Cm = - ar.calculate_moment_coefficient(x, y, Cp, alpha = alpha, c = 1.,
x_ref = x_hinge, y_ref = 0.,
flap = True)
return Cm
def calculate_flap_coefficients(x, y, alpha, x_hinge, deflection, Reynolds = 0,):
"""For a given airfoil with coordinates x and y at angle of attack
alpha, calculate the moment coefficient around the joint at x_hinge
and deflection """
def separate_upper_lower(x, y, Cp = None, i_separator=None):
"""Return dictionaries with upper and lower keys with respective
coordiantes. It is assumed the leading edge is frontmost point at
alpha=0"""
#TODO: when using list generated by xfoil, there are two points for
#the leading edge
def separate(variable_list, i_separator):
if type(i_separator) == int:
variable_dictionary = {'upper': variable_list[0:i_separator+1],
'lower': variable_list[i_separator+1:]}
elif type(i_separator) == list:
i_upper = i_separator[0]
i_lower = i_separator[1]
variable_dictionary = {'upper': variable_list[0:i_upper],
'lower': variable_list[i_lower:]}
return variable_dictionary
#If i is not defined, separate upper and lower surface from the
# leading edge
if i_separator == None:
i_separator = x.index(min(x))
if Cp == None:
x = separate(x, i_separator)
y = separate(y, i_separator)
return x, y
else:
x = separate(x, i_separator)
y = separate(y, i_separator)
Cp = separate(Cp, i_separator)
return x, y, Cp
# If x and y are not dictionaries with keys upper and lower, make them
# be so
if type(x) == list:
x, y = separate_upper_lower(x, y)
upper = {'x': x['upper'], 'y': y['upper']}
lower = {'x': x['lower'], 'y': y['lower']}
#Determining hinge
hinge = af.find_hinge(x_hinge, upper, lower)
upper_static, upper_flap = af.find_flap(upper, hinge)
lower_static, lower_flap = af.find_flap(lower, hinge, lower = True)
upper_rotated, lower_rotated = af.rotate(upper_flap, lower_flap, hinge, deflection)
flapped_airfoil, i_separator = af.clean(upper_static, upper_rotated, lower_static,
lower_rotated, hinge, deflection, N = 5,
return_flap_i = True)
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#Third step: get new values of pressure coefficient
xf.create_input(x = flapped_airfoil['x'], y_u = flapped_airfoil['y'],
filename = 'flapped', different_x_upper_lower = True)
Data = xf.find_coefficients('flapped', alpha, NACA = False,
Reynolds = Reynolds, iteration=500)
return Data