Análise da influência de suportes mecânicos no coeficiente de arrasto em um modelo veicular referência: corpo de ahmed

Abstract

The study of aerodynamic characteristics in simplified models used as a reference in the automotive industry has been crucial for the development of new designs and technologies in vehicles. In this context, the Ahmed body stands out for being a vehicle prototype that allows the study of complex aerodynamic flows, without the need for a complete vehicle model, reducing costs and analysis time. Despite its simple physical characteristics, several studies further simplify Ahmed's models by removing certain elements, such as the supports at the base of the body, the “stilts”. Although this simplification helps to understand specific aspects of aerodynamic behavior, it can leave aside the reality of how the vehicle interacts with the environment in real conditions. In this context, this study experimentally determined the influence of the mechanical support present at the base of the model on the drag coefficient (CD) for a vehicle prototype, known as the Ahmed body. The tests were conducted in a wind tunnel, where a load cell was integrated internally into the model, allowing more reliable measurements without compromising its original geometry. The results showed that with the presence of mechanical support, the CD ranged from 0.35 to 0.39, with an average of 0.37, and for the absence of mechanical support, the CD ranged from 0.37 to 0.31, with an average of 0.34. The presence of support presented CD values from 4.99% to 13.35% higher than without support, with an average of 9.45%. These values indicated that the simplification of removing the support base distances the model from real traffic conditions and should be performed with caution