As always look carefully at your code. Learn to use the debugger. It would tell you the problem, and in which line there was a problem. I scanned through your code, and I saw the error, just waiting to be found. But we can do it the hard way too.
Cs1=4; Cs2=5.6; Cl1=2; Cl2=2.8; ns1=1.5; ns2=-1.5; nl1=1.5; nl2=-1.5;
rho=1.22; A=10; V=44.72; l=20; n=1;Ua=20;
yaw=0:0.5:90;
t=1:1:60;
u=[4.16886273000000 -5.46160601200000 -2.21536928300000 -0.107926889000000 4.17995704900000 2.70294649300000 -3.57644741500000 2.00451722300000 0.881703288000000 4.62541932200000 1.63637915200000 5.73084754400000 0.961007086000000 0.350184264000000 1.37768570200000 -7.64386640500000 1.09384013000000 -3.32210770200000 1.06977546700000 3.77699477800000 -2.80761673400000 -2.51814521100000 -2.56997163700000 -0.434123529000000 -7.33456835300000 3.18164556400000 -2.46259887500000 -2.81705263700000 -6.11824449800000 4.20959983600000 0.958003023000000 1.34911158700000 -3.66536927800000 1.33702769200000 0.951579011000000 4.81211100200000 1.70504507900000 7.08168644200000 3.20839901100000 -0.438521707000000 2.92055007900000 -0.280320940000000 -1.25512163200000 -2.68273256600000 -5.07343734300000 -1.42260189600000 4.56907055100000 3.27623428200000 -1.23514645600000 -2.86948142600000 1.75847520500000 2.79193783800000 -4.18180552400000 -3.14073219500000 -2.43496557500000 -1.28117719800000 4.95079755900000 -3.52809836900000 1.96375591300000 -5.66592848200000]
for i=1:length(yaw)
ms(i)=2*sin(yaw(i)*pi/180)*V/l;
ml(i)=2.5*sin(yaw(i)*pi/180)*V/l;
if yaw(i)<=40
Cs(i)=Cs1*(sin(yaw(i)*pi/180)/sin(30*pi/180))^ns1;
Cl(i)=Cl1*(sin(yaw(i)*pi/180)/sin(30*pi/180))^nl1;
elseif yaw(i)>40
Cs(i)=Cs2*(sin(yaw(i)*pi/180)/sin(30*pi/180))^ns2;
Cl(i)=Cl2*(sin(yaw(i)*pi/180)/sin(30*pi/180))^nl2;
end
S1(i)=0.5*rho*A*(V^2)*Cs(i); % Steady side forces (Uniform along each row)
L1(i)=0.5*rho*A*(V^2)*Cl(i); % Steady lift forces (Uniform along each row)
Msi=ms(i);
Mli=ml(i);
Csi=Cs(i);
Cli=Cl(i);
Yawi=yaw(i*pi/180);
for j=1:length(t)
Tj=t(j);
Uj=u(j);
fun1=@(t1)(((2.*pi.*n.*Msi)^2).*t1.*exp(-2.*pi.*n.*Msi.*t1)).*Uj.*(Tj-t1);
fun2=@(t1)(((2.*pi.*n.*Mli)^2).*t1.*exp(-2.*pi.*n.*Mli.*t1)).*Uj.*(Tj-t1);
S2(i,j)=rho*A*Csi*Ua*(1+(1/(2*Csi))*diff(Csi)*cot(Yawi))*integral(fun1,0,inf); % Unsteady side forces (noniform along each row and column)
L2(i,j)=rho*A*Csi*Ua*(1+(1/(2*Csi))*diff(Csi)*cot(Yawi))*integral(fun2,0,inf); % Unsteady lift forces (noniform along each row and column)
S(i,j)=Sl(i)+S2(i,j); % Total side forces
L(i,j)=S1(i)+S2(i,j); % Total lift forces
j=j+1
end
i=i+1;
end
Now, where are you indexing an array or vector? I found it pretty quickly. What is yaw? yaw is a vector. What do you do with it?
Yawi=yaw(i*pi/180);
Is i*pi/180 a positive integer? I think that is unlikely, given that pi is a transcendental number. What you wanted to do there, I don't know. Maybe you wanted to index the vector yaw to find the ith element, then convert to radians? I cannot guess. Your code, not mine. I'll gues, however, that you WANTD to write:
Yawi = yaw(i)*pi/180;
Since you do something similar in other places.
There may be other errors of this sort, but that was the only one that jumps out.
