//Example 7.5 //Drag force //Page No. 433 clc;clear;close; U=3; //in m/s b=1; //in m L=1; //in m Re_x=5*10^5; //no unit rho=1025; //in kg/m^3 nu=1.044*10^-6; //in m^2/s Re_l=U*L/nu; //reynolds number on the basis of keel length //assuming turbulent boundary-layer Cf=0.074/Re_l^(1/5); Tw=rho*U^2*Cf/2; D1=Tw*b*L; Df=2*D1; printf('\nTotal Drag Force on the keel (assuming turbulent boundary-layer)= %f N',Df); //taking into account the growth of laminar growtn boundary x_tr=Re_x*nu/U; d_tr=x_tr*5/sqrt(Re_x); Cf_lam=1.328/sqrt(Re_x); D1=rho*U^2*b*(Cf*L-Cf*x_tr+Cf_lam*x_tr)/2; Df=2*D1; printf('\nTotal Drag Force on the keel (taking into account the growth of laminar growtn boundary)= %f N\n\n\nNote: Computational Error in the book',Df);