M = 100/6*pi*0.04^3; g=9.8; A=0.25*pi*0.04^2;Re = @(U) 1.25*0.04*U/0.000015;CD = @(Re) 24./Re+(2.6*Re/5)./(1+(Re/5).^1.52)+(0.411*(Re/263000).^(-7.94))./(1+(Re/263000).^(-8))+(0.25*Re/10^6)./(1+Re/10^6);function Udot = Velocity(t,U) Udot = g -(0.5*1.25*U^2*A*CD)/M; [t,U]=ode45 (@Velocity, [0, 20], 0); plot(t,U)end
I'm in agony with this coding for 5hours….. I can solve easy function but it is very complicate function for me. I'm confused how to make up 'Re' 'CD' coding clearly.
Thanks for reading.. how could I get right plotting?
Best Answer