function doublet_in_uniform_flow % clear all; % close all; x=-2.0:0.1:2.0; y=-2.0:0.1:2.0; [X,Y] = meshgrid(x,y); U=1.0; alpha_deg=0; alpha=alpha_deg/180.0*pi; R=0.8; r=sqrt(X.^2+Y.^2); theta = atan2(Y,X); gamma = 1.0; Phi = U*(r+R^2./r).*cos(theta-alpha); Psi = U*(r-R^2./r).*sin(theta-alpha); contour(X,Y,Phi,50,'LineColor','red'); hold on; contour(X,Y,Psi,50,'LineColor','blue'); t = linspace(0,2*pi,100); patch(R*sin(t),R*cos(t),'yellow','FaceAlpha',0.2); end