Drag reduction of a bus model by passive flow canal

Öz

In this study, the drag force of 1/33 scale bus model was improved by passive flow control method. The effect of passive air canal application to drag coefficient was experimentally and numerically investigated on a bus model. Experiments were carried out in the range of 3.8x105 - 7.9x105 Reynolds numbers. The similarity conditions were provided in experimental studies with the exception of the moving road. To provide the geometric similarity condition, the model bus was produced in 3D printer by scanning 3 dimensions. Reynolds number independence was used for dynamic similarity condition. The rate of blockage is 6.81% for kinematic similarity, which is lower than the rate of blockage accepted in the literature. Respectively 4.21%, 7.48% and 12.19% aerodynamic improvement achieved with 1, 3, and 5 passive air canals whose diameter 6 mm. Flow analysis was performed in Fluent® program of the model 3 bus to view the flow structure around the bus. The numerical results support to wind tunnel results. In this study the effect of obtained aerodynamic improvements by applied passive flow control method can decrease fuel consumption about 2-6% at high vehicle speeds.

Anahtar Kelimeler

• Aerodynamic,bus model,wind tunnel,CFD,passive flow control method

Kaynakça

1. Bellman, M. Agarwal, R. Naber, J. and Chusak, L. (2010) Reducing energy consumption of ground vehicles by active flow control. In ASME 2010 4th International Conference on Energy Sustainability. pp 785-793. American Society of Mechanical Engineers.
2. Moussa, A.A. Fischer, J. and Yadav, R. (2015). Aerodynamic Drag Reduction for a Generic Truck Using Geometrically Optimized Rear Cabin Bumps Journal of Engineering vol. (2015). pp:2-14.
3. Jonathan, M. Erik, F. Gregory, R. Rajan, K. Kunihiko, T. Farrukh, A., Yoshihiro, Y. and Kei M. (2015). Drag reduction on a flat-back ground vehicle with active flow control. J. Wind Eng. Ind. Aerodyn. 145, 292–303.
4. Shim, H.S. Lee, Y.N. Kim, K.Y. (2017). Optimization of bobsleigh bumper shape to reduce aerodynamic drag” Journal of Wind Engineering & Industrial Aerodynamics 164,108–118.
5. 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.
6. Gurlek, C. Sahin, B. Ozkan, G.M. (2012). PIV studies around a bus model”, Experimental Thermal and Fluid Science 38, 115–126.
7. Lin, M. Dajun, Z. Wanshui H. Jun, W. and Jianxin, L. (2016). Transient aerodynamic forces of a vehicle passing through a bridge tower’s wake region in crosswind environment. Wind and Structures, 22-2, 211-234.
8. 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.

9. 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.
10. 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.
11. Bayindirli, C. and Çelik, M. (2018). The Experimentally and Numerically Determination Of The Drag Coefficient Of A Bus Model International Journal of Automotive Engineering and Technologies, 7 (3) 117-123.
12. Çengel, Y.A., and Cimbala, J.M. (2008). Akışkanlar Mekaniği Temelleri ve Uygulamaları. Güven Bilimsel Yayınları, 562-599.
13. Ince, İ.T.(2010). Aerodynamic Analysis of GTD Model Administrative Service Vehicle. PhD Thesis, Gazi Universty Institute of Science, Ankara, 30-66.
14. Akansu, Y. E., Bayındırlı, C., Seyhan M. (2016). The improvement of drag force on a truc trailer vehicle by passive flow control methods, J. of Thermal Science and Technology, 36, 1, 133-141.