Effect of a Flush to Outer Skin Arrangement on the Aerodynamic Characteristics of Active Grille Shutters

In the present work, it is investigated how a flush arrangement to the outer skin affects the aerodynamic characteristic curve of active grille shutters (AGS). For this purpose, a recently developed theory, which analytically describes the aerodynamic behavior of AGS arranged in a straight flow channel, is extended accordingly, and the influence of an arrangement of AGS flush with the outer skin is first theoretically analyzed. The theoretical results are then validated experimentally. For this purpose, measurements of real vehicles with suitable AGS are used. The results show a good agreement of the theoretical predictions with the experiment. The theoretical and experimental analyses allow conclusions to be drawn as to how and under what conditions an arrangement flush with the outer skin affects the aerodynamic behavior of AGS.