removal of error in matlab code

I have had various errors, read through the guidance on Integral and function handles, but cannot seem to find the solution...Any help or guidance would be very much appreciated.... Here is my code (it requires the Optimization Toolbox):

%Us=;%.1-10
%Ch and Cmb frm the eqn 34 and 47
i=0;
x=zeros(31);
y=zeros(31);
D=.05;
dp=.003;
Cb=.52;
Cs=11;%4.2 7.6 11.7 15.5
Ch=Cs;
alph=.046;
bth=.2;

%((180*acos((2*yb/D)-1)/pi)-((2*yb/D)-1)*(1-((2*yb/D)-1)*sqrt((2*yb/D)-1)));%11
%plot(Us,press_loss)

%Re=rowh*Uh*Dh/muh;
rows=1240;
rowL=1000;%not confirm
s=rows/rowL;
g=9.81;
rowh=rows*Ch+rowL*(1-Ch);

for Us=1:.1:4
    i=i+1;      

      CD=.44;
      omega_0=sqrt((4/3)*(((s-1)*dp*g)/CD));
      C=.001;%this is wrong
      m=2.39;
      omega=omega_0*((1-C)^m);%from the eqn 21
      i=0;
      D=.05;
      incr=pi/(2*100);
      for gamma=pi/(2*200):pi:incr
          Ryb=.5*D-.5*cos(pi*gamma/180);
          Ah=.25*D*D*((180/pi)*acos(2*Ryb/D-1)-(2*Ryb/D-1)*sqrt(1-(2*Ryb/D-1)*(2*Ryb/D-1)));
          Sh=D*(180*acos((2*Ryb/D)-1)/pi);
          Si=D*sqrt(1-(2*Ryb/D-1)*(2*Ryb/D-1));
          Dh=4*Ah/(Sh+Si);
          A=pi*D*D*.25;
          %yb=.04;%wrong next line is for yb
          eps=.000000001;
          Uh=Us*A/Ah;
          muh=rowh*Uh*Dh/500;%from reynolds number put muh
          fh=alph*(rowh*Uh*Dh/muh)^bth;
          tauh=.5*rowh*Uh*Uh*fh;
          Reh=rowh*Uh*Dh/muh;
          f=@(z) 1/sqrt(2*z)+.86*log((dp/Dh)/3.7+2.52/(Reh*sqrt(2*z)));
          f1=fsolve(f,10e-3);
          r=Dh;
          Ustar=Uh*sqrt(f1/2);
          ep=.052*Ustar*r;%from the eqn 20
          thtb=gamma;
          func=(D*D/(2*Ah))*exp(-(omega*D/(2*ep))*(sin(x)-sin(gamma)))*(cos(x))^2;
          intgr=integral(func,thtb,pi);
          if Cs/Cb-intgr<eps
              i=i+1;%this will count the number times the loop continue
              Rthtb=thtb;
          end
      end 
      x(i)=Us;
      y(i)=press_loss;
      yb=.5*D-.5*cos(pi*Rthtb/180);
      RSh=D*(180*acos((2*yb/D)-1)/pi);
      RSi=D*sqrt(1-(2*yb/D-1)*(2*yb/D-1));
      taui=.5*f1*rowh*Uh*Uh;
      press_loss=(-(tauh*RSh)-(taui*RSi))/Ah;
  end
  %although in previous it is written that Ryb as variable and yb as value of
  %exact yb RSh and RSi as value of exact and RSi and RSh as variable
plot(x,y)

Answer 1

[Star Strider]

It’s obvious just by looking that this is a significant problem:

func=(D*D/(2*Ah))*exp(-(omega*D/(2*ep))*(sin(x)-sin(gamma)))*(cos(x))^2;

You’re intending to create an anonymous function, but you’re missing the function handle creation and argument list. What argument do you want to integrate over? It should go where the ‘?’ is here:

func = @(?) (D*D/(2*Ah))*exp(-(omega*D/(2*ep))*(sin(x)-sin(gamma)))*(cos(x))^2;

Don’t worry about the other variables — the anonymous function will get them from your workspace.