Experimental study on the aerodynamic effects of a forward-sweep angle

An experimental study to investigate some aerodynamic features of forward-swept wings is described. Pressure distributions on two wing models with different sweep angles (A = 0 deg and A = — 25 deg) were evaluated by means of 320 measurement points, up to angles of attack of 28 deg, in low subsonic and transonic regimes. A comparison of the aerodynamic behavior of the two wings, both at low and high angles of attack (stall and poststall conditions) is presented. At low Mach numbers and low angles of attack the experimental data were also compared with numerical results obtained with a panel code. Some characteristics of the forward sweep are discussed and the benefits that can be obtained by applying it in conditions of interference with other lifting surfaces are pointed out.