% pressure gradient (if convection is used)
dpdx = 5; 
% A = 0 -> pure conduction problem (heat eqn)
% A = 1 -> conduction and convection problem (CD eqn)
A = 0;
% velocity
U = A*(dpdx/(2*alpha))*( (Ly/2)^2 - (Y-Ly/2).^2); 
V = 0*U;