The Experimentally and Numerically Determination Of The Drag Coefficient Of A Bus Model

Cihan Bayındırlı, Mehmet Çelik
229 77


In this study, the drag coefficient of a 1/33 scaled bus model were determined by experimentally in wind tunnel and numerically in Fluent®. The tests were performed at 6 different free flow rates and between the range of 382 866- 792 900 Reynolds numbers and 13.54m/s - 28.05m/s free flow velocity. The three similarity conditions were provided in tests. The flow analyses were conducted in 1/40 scaled wind tunel as experimentally using Reynolds independent. The aerodynamic drag coefficient (CD) of the bus model was calculated as 0.633 in wind tunnel. The experimental results of bus model are verificated by numerical flow analysis in Fluent® program. According to numerical results, the drag coefficient of bus model is calculated as 0.645 with 1.81% error margin.


Vehicle aerodynamic, drag coefficient, wind tunnel, bus model, CFD, Fluent

Full Text:



-Wood, R.M. and Bauer, S.X.S. (2003), Simple and low cost aerodynamic drag reduction devices for tractor-trailer trucks. SAE Technical Paper, 01–3377, 1-18.

- Cui, W. Zhu, H. Xia, C. Yanga, Z. (2015). Comparison of steady blowing and synthetic jets for aerodynamic drag reduction of a simplified vehicle. Procedia Engineering 126, 388 – 392.

- Mohamed- Kassim, Z. Filippone, A. (2010). Fuel savings on a heavy vehicle via aerodynamic drag reduction. Transportation Research Part D 15, 275–284.

- Ji-qiang, N. Dan, Z. Xi-feng, L. (2017). Experimental research on the aerodynamic characteristics of a high-speed train under different turbulence conditions. Experimental Thermal and Fluid Science 80,117–125.

-Hassan S.M.R. Islam, T. Ali, M. Islam, Md. Q.(2014). Numerical Study on Aerodynamic Drag Reduction of Racing Cars. Procedia Engineering 90, 308 – 313.

-Chilbule, C. Upadhyay, A. Mukkamala, Y. (2014). Profile modification of truck-trailer to prune the aerodynamic drag and its repercussion on fuel consumption. Procedia Engineering 97, 1208 – 1219.

- Patil, C.N. Shashishekar, K.S. Balasubramanian, A.K. Subbaramaiah, S.V. (2012). Aerodynamic Study and drag coefficient optimization of passenger vehicle. International Journal of Engineering Research & Technology (IJERT), 1(7), 1-8.

- Chowdhury, H. Moria, H. Abdulkadir, A. Khan I. Alam, F. and Watkins, S. (2013). A Study on aerodynamic drag of a semi-trailer truck. Procedia Engineering, 56, 201–205.

- Akansu, Y. E. Özmert, M. Fırat E. (2011). The effect of attack angle to vortex shedding phenomenon of flow around a square prism with a flow control rod. Journal of Thermal Science and Technology, 31, 1, 109-120.

- Bayındırlı, C., Çelik, M., Demiralp, M. (2018). The investigation of flow characteristic around a bus model by CFD method and improvement of drag force by passive flow control method. Journal Of Politeknik, Early appearance format (DOI:10.2339/politeknik.403993)

- Çengel, Y.A., and Cimbala, J.M. (2008). Akışkanlar Mekaniği Temelleri ve Uygulamaları, Güven Bilimsel Yayınları, 562-599.

- İnce, İ.T.(2010). Aerodynamic Analysis of GTD Model Administrative Service Vehicle PhD Thesis, Gazi Universty Institute of Science,Ankara, 30-66.

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

ISSN: 2146-9067