Date of Award


Publication Type


Degree Name



Mechanical, Automotive, and Materials Engineering

First Advisor

Shaohong Cheng

Second Advisor

David S-K Ting


Applied sciences



Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.


The continuously increasing gasoline and diesel fuel costs generated immense interest in road vehicle efficiency. Because the aerodynamic drag of road vehicles is a major contributor to the fuel consumption at highway speeds, renewed interests are focusing on attempts to find novel drag-reducing technology. In this project, a newly designed air deflector with the shape of three concave surfaces was proposed. The effect of the deflector shape on the aerodynamic performance of a truck model, such as drag coefficient, was investigated. The results were compared to the same truck model with conventional convex deflector and without deflector. The relationship between the deflector shape and the drag force coefficient, as well as Reynolds number was revealed in all cases. The impact of deflector details on the characteristics of the airflow around the truck model, focusing on the wake area behind the trailer was also investigated.