Numerical investigation of aerodynamic of a car with various vortex generators

Öz

In this study, the aerodynamic characteristics of a 1:5 scale passenger car with trapezoidal and curved wing vortex generators was investigated numerically. The vehicle design was made with the CATIA V5R21 and the ANSYS was used for the geometric, numerical solution and meshing. The air velocity was kept constant at 100 km/h and the solution of the flow field was completed with the realizable k-ɛ turbulence model. Eight vortex generators at 100 mm intervals were placed 15 mm ahead of the flow separation point formed at the back of the vehicle roof. The flow structure of the vehicle with vortex generators was examined with velocity distributions, pressure distributions and aerodynamic coefficients, and compared with the results without the vortex generator. The results showed that the flow field and aerodynamic characteristics behind the vehicle were affected by the presence and structure of vortex generators. The use of the curved wing vortex generator caused a 2.87% reduction in the drag coefficient, while this rate was determined as 2.20%, in the model using trapezoidal wing vortex generator. The maximum increase in the lift coefficient was found in the model with the trapezoidal wing vortex generator of 3.3%.

Anahtar Kelimeler

• Vortex generators
• Drag coefficient
• Passenger car
• Lift coefficient

Farklı girdap üreteçlere sahip bir aracın aerodinamiğinin sayısal incelenmesi

Öz

Bu çalışmada 1:5 ölçekli yamuk ve kavisli kanat girdap üreteçlere sahip binek bir aracın aerodinamik özellikleri nümerik olarak araştırılmıştır. Araç tasarımı CATİA V5R21 ile yapılırken, geometrik düzenlemeler, sayısal çözüm işlemleri ve ağ örme için ANSYS programı kullanılmıştır. Hava hızı 100 km/h olarak sabit tutulmuş ve akış alanının çözümü realizable k-ε türbülans modeli ile yapılmıştır. 8 adet girdap, basınç dağılımları ve aerodinamik katsayılar incelenerek, girdap üreteci kullanılmamış durumdaki sonuçlarla karşılaştırılmıştır. Sonuçlar aracın arka kısmındaki akış alanının ve aerodinamik karakteristiklerin girdap üreteçlerin varlığından ve yapısından etkilendiğini göstermiştir. Kavisli kanat girdap üretecin kullanılması sürüklenme katsayısında %2.87 oranında bir azalmaya sebep olurken, yamuk kanat girdap üretecinin kullanılması durumunda bu oran %2.20 olarak tespit edilmiştir. Kaldırma katsayısındaki maksimum artış %3.3 olarak yamuk kanat girdap üreteç kullanılması ile elde edilmiştir.

Anahtar Kelimeler

• girdap üreteçleri
• sürüklenme katsayısı
• binek araç
• Kaldırma katsayısı

Kaynakça

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