Numerical simulation of a tandem configuration of both I-shape and circular cylinder at two-dimensional. Diameter of circular cylinder is D as the bluff body and I-shaped cylinder has diameter of d with a cutting angle 53o as passive control, that is located in front of the bluff body. Navier Stokes equations are used to solve this problem and solved with a finite difference method. When we put the Reynolds number of Re = 100, the domain distance between bluff body and passive control is a S=D = 0:6; 1:2; 2:4 and 3:0 then we obtain profile streamline around the bluff body,
pressure distribution, separation point on the top around the 125o and on the bottom around 225o, and mathematical models of drag cofficient.