Comparison of Lift and Drag Forces for Some Conical Bodies in Supersonic Flow Using Perturbation Techniques


Mechanical Engineering, Ferdowsi University of Mashhad


Numerical methods are not always convergent especially in higher velocities when shock waves are involved. A comparison analysis is performed to study the supersonic flow over conical bodies of three different cross sections circular, elliptic and squircle (square with rounded corners) shaped using  Perturbation techniques to find flow variables analytically. In order to find lift and drag forces the pressure force on the body is found, the component along x is drag and the component along z is lift. Three equations are obtained for lift to drag ratio of each cross section. The graphs for L/D show that for a particular cross section an increase in angle of attack, increases L/D. Comparing L/D in the three mentioned cross sections depicted that L/D is the greatest in squircle then in ellipse and the  least in circle. The results are efficient in design of flying objects.