Numerical Analysis of Two Models of Air Deflectors to Improve the Aerodynamics of a Heavy Truck

Abstract

Fuel consumption and pollutant gas emissions are major issues that affect the heavy-duty truck industry. The installation of air deflectors on the roof of truck cabins is a widely adopted strategy to reduce drag and improve aerodynamics. The latter is directly related to fuel consumption and pollutant gas emissions. This study aims to identify the optimal air deflector design to improve aerodynamic performance. Seven vehicle body configurations were modelled using SolidWorks 3D design software: a basic model (truck without a deflector) and six models equipped with deflectors. Computational fluid dynamics (CFD) analyses were conducted for each configuration to determine the most aerodynamically efficient structure. The results reveal that models with air deflectors achieved reductions in static pressure (ranging from 0.17% to 1.73%) and velocity (ranging from 1.2% to 5%) compared to the basic model. These findings confirm the critical role of air deflectors in enhancing aerodynamic performance and reducing drag force. Among the different models, the first deflector (case 1) stands out for its best performance, with an estimated drag coefficient reduction of 19.80% and a corresponding decrease in fuel consumption of 19.79%. In conclusion, these results show that drag reduction directly impacts fuel economy.