how can i find point of separation for flow past a circular cylinder?

R=0.1;v=2/10^6;U=1;L=7.052; %z=(1/63)^2*(37/5-L/15-L*L/144)^2*sqrt(L*DU/v); x=0:0.01:1; i=1; z(1)=91.7324; while L<12 t=x(i)/R;DU=2*U*cos(t)/R; f1=63*(3-L/12)/10/(37/5-L/15-L*L/144); f2=(1/63)*(2+L/6)*(37/5-L/15-L*L/144); k=(1/63)^2*(37/5-L/15-L*L/144)^2*L; H=2*f2-2*(2+f1)*k; z(i+1)=z(i)+H/U*0.01; c= 0 ; while abs(z(i+1)-(1/63)^2*(37/5-L/15-L*L/144)^2*sqrt(L*DU/v))>0.01 &&L<12 L=L+0.001; c= c+1 ; end

    i=i+1;
end

disp(x(i-1)/R); disp(i)

disp(L)

%t=0;R=0.1;v=2/10^6;U=1;L=7.052;DU=2*U*cos(t)/R; %z=(1/63)^2*(37/5-L/15-L*L/144)^2*sqrt(L*DU/v); %disp(z);Z=90; %while abs(Z-z)>0.01 % L=L+0.001; % z=(1/63)^2*(37/5-L/15-L*L/144)^2*sqrt(L*DU/v); %end %disp(L);