Development of Pneumatic Aerodynamic Concepts for Control of Lift, Drag and Moments plus Lateral/Directional Stability of Automotive Vehicles

An experimental/computational research program has been conducted to evaluate and confirm a patent-pending pneumatic concept intended to improve aerodynamic problem areas of automobiles. These areas of concern include: separated flow and drag reduction; lift, side force and moment control; and lateral/directional stability. The pneumatic concept applied uses a form of blowing which has proven quite effective in aircraft applications because of its very large aerodynamic returns from minimal blowing input. During this research program, this blowing system was installed in models of generic streamlined automobiles and its effect on aerodynamic and control improvements was investigated. Initial wind-tunnel evaluations revealed that the unblown streamlined model exhibited all of the above areas of concern. Pressure distributions on the vehicle were used to design an effective blowing concept which improved vehicle aerodynamics by enhancing the local flowfields. Control of separating flows and vortex formations was also demonstrated. Experimental and computational results are presented, as are discussions of the test procedures and flow visualizations. These data confirm the potential of these no-moving-part pneumatic concepts in improving the aerodynamic characteristics, control and stability of streamlined automotive vehicles, especially when operating in sidewinds or gusts.