# Function works with one input but not the other

2 views (last 30 days)
Samir Chaouki on 14 Apr 2022
Commented: Samir Chaouki on 14 Apr 2022
Im using the optimisation tool and have set everything up following the tutorial on the mathwork website, the tool works when the input is Y but not when the input is T_to, which is what id like it to be. T_to input only works when the number of variables is one, which doesnt give me a useful result.
I should disclose im still very new to matlab so its possible that the problem is very simple.
function F = mymulti1(T_to)
y = 20640000;
%T_to = 3050; %degC
A_choke = 0.0531; %m^2
A_Rat = 78;
A_Exit = A_choke * A_Rat; %m^2
T_Exit = 343.2;
M_Exit = 1.65; %Ratio
Gamma = 1.26; %Const
Gas_const = 287.5; %Const
MFR = ((A_choke * y) ./ (sqrt(T_to))) * (sqrt(Gamma / Gas_const)) * ( ((Gamma + 1) / 2)^-((Gamma + 1) / 2*(Gamma - 1)));
Pressure_Exit = (1 + ((Gamma - 1) / 2) * ((M_Exit) ^ 2))^ - (Gamma /(Gamma - 1)) * y;
Velocity_Exit = M_Exit * sqrt(Gamma * Gas_const * T_Exit);
Thrust = (MFR .* Velocity_Exit) + (A_Exit * Pressure_Exit);
F(2) = Thrust ./ MFR ;
F(1) = (y .* A_choke) ./ MFR;
end

VBBV on 14 Apr 2022
F(2,:) = Thrust ./ MFR ;
F(1,:) = (y .* A_choke) ./ MFR;
Check the size of output matrix
Samir Chaouki on 14 Apr 2022
Hi VBBV,
you've helped already a massive amount but if i could just trouble you a little more.
attached is the plot ive got and the kind of plot im trying to get. what would you recommend i do?
Thanks
Samir

R2021b

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