updated range/cruise/power

Model/Propulsion/cruise_comp.py

@@ -13,6 +13,7 @@ def setup(self):
         self.add_input('AR',desc='Aspect Ratio')
         self.add_input('S',desc='Refernce Area')
         self.add_input('V',desc='Airspeed')
+        self.add_input('cd0',desc='zero lift drag')
 
         self.add_output('P_C',desc='Power required for cruise')
 
@@ -22,4 +23,9 @@ def setup(self):
 
     def compute(self,inputs,outputs):
         W = inputs['W']*9.81 
-        outputs['P_C'] = (( (2*(W**3)*(inputs['Cd']**2))/(inputs['S']*rho*(inputs['Cl']**3)) )**.5)/1000
+        # add Cl & Cd if airfoil code doesnt work
+        cl = 2*W/(rho*(inputs['V']**2)*inputs['S'])
+        k = 1/(3.14*0.8*inputs['AR']) # e = 0.8
+        cd = inputs['cd0'] + k*cl**2
+        #outputs['P_C'] = (( (2*(W**3)*(inputs['Cd']**2))/(inputs['S']*rho*(inputs['Cl']**3)) )**.5)/1000
+        outputs['P_C'] = (( (2*(W**3)*(cd**2))/(inputs['S']*rho*(cl**3) ))**.5)/1000

Model/Propulsion/power_comp.py

@@ -27,12 +27,13 @@ def compute(self, inputs, outputs):
         rho = inputs['rho']
         tip_speed = inputs['TS']
         cd0 = inputs['cd0']
+        sol = 0.1 
 
 
         S = 3.14*(r**2)
         T = n*W/8 # thrust required per motor
         ct = T/( rho *S* (tip_speed**2) )
-        cp = ( 1.15*( (ct**(3/2)) /(2**.5) ) + (1/8)*0.1*cd0 )
+        cp = ( 1.15*( (ct**(3/2)) /(2**.5) ) + (1/8)*sol*cd0 ) # solidity
         PI = T * ((T/(2*S*rho))**.5)
         PH = cp*rho*S*(tip_speed**3)
         FM = PI/PH

Model/Propulsion/range_comp.py

@@ -21,7 +21,7 @@ def setup(self):
     def compute(self,inputs,outputs):
         LO_Wh = inputs['P_L']*LO_time*1000  # Energy spent on liftoff
         time = ( (B_density*inputs['B_W']*res)-LO_Wh-(LO_Wh/2) ) / (1000*inputs['P_C'])
-        dist = (time-FAA)*inputs['V']
+        dist = (time-FAA)*inputs['V']*3.6   #conversion from [m/s]->[kph]
 
         outputs['R'] = dist
         outputs['t'] = time

solver.py

@@ -17,12 +17,12 @@
 
 ivc.add_output('m',val=0.0)
 ivc.add_output('r',val=0.0)
-ivc.add_output('TS',val=170)
+ivc.add_output('TS',val=175) # ~55% of mach @ Sl
 ivc.add_output('cd0',val=0.0197)
 ivc.add_output('rho',val=1.225)
 
-ivc.add_output('V',val=180)
-ivc.add_output('Cd',val=0.0255)
+ivc.add_output('V') # [m/s],~230[mph]
+ivc.add_output('Cd',val=0.03)
 ivc.add_output('Cl',val=0.32)
 ivc.add_output('S',val=13.2)
 ivc.add_output('AR',val=7)
@@ -52,6 +52,7 @@
 model.connect('AR','cruiseP.AR')
 model.connect('S','cruiseP.S')
 model.connect('V','cruiseP.V')
+model.connect('cd0','cruiseP.cd0')
 
 # connecting to range comp
 model.connect('Wb','range.B_W')
@@ -62,36 +63,46 @@
 
 prob.driver = ScipyOptimizeDriver()
 prob.driver.options['optimizer'] = 'SLSQP'
-prob.driver.options['tol'] = 1e-7
+prob.driver.options['tol'] = 1e-9
 prob.driver.options['disp'] = True
 
 model.add_design_var('r',lower=0.5,upper=1.5)
-model.add_design_var('We/W0',lower=0.30,upper=0.70) # 30% - 70%, from lecture
-model.add_constraint('weight.W0',lower = 1700,upper=2500)
-model.add_constraint('FOM.FM',equals=0.8)
-model.add_objective('FOM.PH')
+model.add_design_var('We/W0',lower=0.50,upper=0.70) # 30% - 70%, from lecture
+model.add_design_var('V',lower=67,upper=103)
+
+
+model.add_constraint('FOM.FM',equals=0.80)
+model.add_constraint('weight.W0',lower=1700,upper=2500)
+model.add_constraint('FOM.PH',upper=500)
+model.add_constraint('cruiseP.P_C',upper=90)
+model.add_objective('range.R')
 
 prob.setup()
 
 # Initial Guesses
-prob['We/W0'] = 0.60
-prob['r'] = 1.5
+prob['We/W0'] = 0.6
+prob['r'] = 1
 # guesses from CDR
+#BASED ON INITIAL GUESS THE OPTIMZER MIGHT PICK A LOCAL MINIMA INSTEAD OF GLOBAL
 prob['AR'] = 7
 prob['S'] = 13.2
-prob['V'] = 230
-prob['Cd'] = 0.03
-prob['Cl'] = 0.32
+prob['V'] = 90
+prob['Cd'] = 0.03 # not used for calculation but here to run
+prob['Cl'] = 0.32 # not used for calculation but here to run
+#prob['TS'] = 170
+
 
 
 #prob.run_model()
 prob.set_solver_print(level=0)
 prob.run_driver()
-print('Gross Weight Fraction:',prob['We/W0'])
+print('Tip Speed',prob['TS'],'[m/s]')
+print('Empty Weight Fraction:',prob['We/W0'])
 print('Gross Weight:',prob['weight.W0'],'[kg]')
 print('Figure of Merit:',prob['FOM.FM'])
 print('Required Radius:',prob['FOM.r'],'[m]')
 print('Required Power for Hover:',prob['FOM.PH'],'[kW]')
 print('Required Power for Cruise:',prob['cruiseP.P_C'],'[kW]')
-print('Range Not Using Reserve and battHealth :',prob['range.R'],'[km]')
+print('Max Trip Range @',prob['V'],'[m/s]:',prob['range.R'],'[km]','Time',prob['range.t'],'[hr]')
+