Minimization with multiple inputs

You

% Atmosphere 
Ta = 219 %k 
Pa = 4000 %Pa
Ca = 296.4 %m/s 
Rhoa = .06372 %kg/m^3 
As = 585 %m^2 
M = 3  
Cd = .013  
Cl = .094 
alpha = 4.5 * (pi/180) %rad 
Va = M * Ca %m/s 
L = Cl * .5 * Rhoa * (Va.^2) * As
D = Cd * .5 * Rhoa * (Va.^2) * As 
FtTotal = D / cos(alpha) %Total 
Thrust Ft = FtTotal / 3 %Thrust per Engine (3) 
AirFrame = 1.128e6 %N 
FuelWeight = 272000 %N 
FuelMass = 27700 %kg 

Engine Design and Optimization Validation with Nominal Configuration

% Diffuser 
ka=1.4 
Poa = Pa*((1 + ((ka-1)/2)*(M^2))^(ka/(ka-1))) %Pa 
Toa = Ta*((1 + ((ka-1)/2)*(M^2))) %K 
T1 = Toa %K 
rd = .80886 
P1 = rd * Poa %Pa 
% Fan
rf = 1.99 
P2 = rf * P1  
npf = .89 
T2a = T1 * (rf)^((ka-1)/(ka*npf)) 
% Compressor 
rc = 15 
P3 = rc * P2 
npc = .89 
T3a = T2a * (rc)^((ka-1)/(ka*npf)) 
% Combustor 
Cpa = 1005 %J/kgK 
Cpg = 1157 %J/kgK 
hc = 43.1e6 %J/kg Assume Jet Fuel 
T4 = 2000 %K 
Tref = 298 %K 
= (Cpg*(T4-Tref) - Cpa*(T3a-Tref))/(hc - Cpg*(T4-Tref)) 
Plc = .97 
P4 = Plc * P3 
% Turbine 
BPR = 1 
nm = .99 
T5a = T4 - (((1+BPR)*Cpa*(T2a-T1) + Cpa*(T3a-T2a))/(nm*(1+f)*Cpg)) 
npt = .93 
kg = 1.33 
P5 = P4*((T5a/T4)^(kg/((kg-1)*npt))) 
% Nozzle Exit 
% Guess Unchoked 
Pln = 1 
Poce = Pln * P5 
Pce = Pa 
Mce = sqrt(2*(((Poce/Pce)^((kg-1)/kg))-1)/(kg-1)) 
Toce = T5a 
Tce = Toce/(1 + ((kg-1)/2)*(Mce^2)) 
R = 287 %J/kgK 
Vce = Mce * sqrt(kg*R*Tce) 
rhoce = Pce/(R*Tce) Ace = 7.8407 %m^2 
mdotce = rhoce * Vce * Ace %kg/s 
mdotca = mdotce / (1+f) 
% Bypass Duct Nozzle 
% Assume Choked 
Pld = 1 
Pofe = Pld * P2 
Mfe = 3.32 
Pfe = Pofe/((1+ ((ka-1)/2)*(Mfe^2))^(ka/(ka-1))) 
Tofe = T2a  
Tfe = Tofe/(1 + ((ka-1)/2)*Mfe^2) 
Cfe = sqrt(ka*R*Tfe) 
Vfe = Mfe * Cfe 
mdotfe = BPR * mdotca 
mdota = mdotca + mdotfe 
rhofe = Pfe/(R*Tfe) 
mdotf = mdotce - mdotca 
Afe = 4.4065 
Ft = mdotfe*Vfe + mdotce*Vce - mdota*Va + (Pfe-Pa)*Afe

Code above works entirely. Need to minimize 'mdotf' while holding 'Ft' to 64000. Plc and Pld cannot exceed 1. BPR cannot exceed 2. Rc and Rf must be 1.0 or greater. Would like to display mdotf, BPR, rc, rf, Afe, Ace, Pld, Plc.

[Image Analyst]

Please format your code as code with the code button.

Explain what these two lines mean:

Tref = 298 %K 
= (Cpg*(T4-Tref) - Cpa*(T3a-Tref))/(hc - Cpg*(T4-Tref)) 

[R]

The "fmincon" function in MATLAB's Optimization Toolbox might help you solve this optimization problem. Refer to the following documentation:

https://www.mathworks.com/help/optim/ug/fmincon.html