Análise experimental da aerodinâmica de um veículo coletivo de transporte de passageiros em túnel de vento

Abstract

This study aims to experimentally analyze the aerodynamic behavior of a heavy passenger vehicle, aiming to determine its dimensionless coefficients and quantify the impact of aerodynamic drag on fuel consumption and carbon dioxide ( CO2) emissions. The methodology was divided into qualitative and quantitative approaches conducted in a wind tunnel. Qualitatively, smoke injection was employed to visualize the flow topology, highlighting boundary layer separation and the formation of a large turbulent wake inherent to bluff bodies. Quantitatively, the incident forces were measured on a scaled model inspired by the Marcopolo Paradiso New G7 1800 DD coach. The acquired data underwent time-averaged statistical treatment and analytical refinement through force superposition, isolating the parasitic drag from the mounting support. The results demonstrated that the Reynolds number independence regime was reached for flows above 13,9 𝑚/𝑠, consolidating a drag coefficient of 0.7480. An incomplete dimensionless analysis extrapolating the scaled model to the full-size prototype operating at a cruising speed of 90 𝑘𝑚/ℎ indicated a power requirement of 119,43 kW, resulting in an estimated fuel economy of 2,98 𝑘𝑚/𝐿 and an emission factor of 0,8998 kgCO2/km. It is concluded that aerodynamic drag constitutes the dominant portion of energy losses, and that the experimental obtainment of these parameters provides essential data for the geometric refinement of commercial fleets, promoting the reduction of logistical costs and the mitigation of environmental impacts.