Effectiveness of Drag Reduction Device on Simplified Vehicle Model: A CFD Study

Md. Bulbul Ahmed Rubel; Prasanjit Das Das; Itquan Hossen

doi:10.38032/scse.2026.4.139

Authors

Md. Bulbul Ahmed Rubel Department of Mechanical Engineering, Chittagong University of Engineering & Technology, Chattogram-4349, Bangladesh
Prasanjit Das Das Department of Mechanical Engineering, Chittagong University of Engineering & Technology, Chattogram-4349, Bangladesh
Itquan Hossen Department of Mechanical Engineering, Chittagong University of Engineering & Technology, Chattogram-4349, Bangladesh

DOI:

https://doi.org/10.38032/scse.2026.4.139

Keywords:

Aerodynamic Drag, Wake Region, Diffuser, Turbulence, Optimization

Abstract

Aerodynamic drag significantly influences vehicle performance and fuel efficiency, making its reduction a key focus in automotive design. This study examines the drag reduction of the simplified Ahmed body model by integrating diffusers at 8° and 10° angles. Using Computational Fluid Dynamics (CFD) simulations, airflow analysis was conducted on Ahmed bodies with 25° and 30° slant angles, both in baseline and modified configurations. The results show that diffuser-equipped models achieved a notable reduction in drag coefficient compared to the original design and previous literature. This improvement is primarily due to minimized turbulence in the wake region, as the diffuser slows airflow and enhances pressure recovery, thereby lowering drag. Both 25° and 30° slant configurations demonstrated substantial aerodynamic benefits with diffuser integration, with greater improvements observed at higher slant angles. Overall, the study highlights the effectiveness of diffusers in enhancing aerodynamic efficiency, offering valuable insights for vehicle design aimed at improving fuel economy, performance, and sustainability.

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References

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