Drag Coefficient Determination Of A Bus Model Using Reynolds Number Independence

Öz

It is needed to great time and cost to determine drag coefficients of vehicles with full-scale wind tunnels. In this study, drag coefficient of a blunt bus model was tried to be determined using Reynolds number independence. A low speed wind tunnel having a free flow velocity is 28 m/s and has a rectangular cross section of high and wide, was used in experiments. The flow around the bus model was simulated with ANSYS CFX at wind tunnel conditions. As a result, aerodynamic drag coefficient of the bus model was determined as 0,66 and 0,65 according to results of CFX and experiment respectively after Reynolds number 57000. It is determined that the drag coefficient of the blunt vehicles can be determine by using low speed wind tunnel and Reynolds number independence.

Anahtar Kelimeler

• Drag coefficient, Reynolds number, vehicle aerodynamic, drag force, performance

Reynolds sayısı Bağımsızlık kullanma A Otobüs Modelinin sürükleyin Katsayısı Tayini

Öz

Bu tam ölçekli rüzgar tünellerinin araçların sürükleme katsayıları belirlemek için büyük bir zaman ve maliyet gereklidir. Bu çalışmada, künt otobüs modelinin sürtünme katsayısı Reynolds sayısı bağımsızlığı kullanılarak tespit edilmeye çalışılmıştır. Serbest akış hızına sahip olan bir düşük hız rüzgar tüneli 28 m / s olup, yüksek ve geniş bir dikdörtgen şeklinde bir enine kesite sahiptir, deneylerinde kullanılmıştır. Otobüs modeli etrafında akış rüzgar tüneli koşullarında ANSYS CFX ile simüle edildi. Sonuç olarak, otobüs modelinin aerodinamik sürtünme katsayısı sırasıyla Reynolds sayısı 57000. Bu künt araçların sürtünme katsayısı kullanarak belirlemek olabilir tespit edildikten sonra CFX sonuçlarına ve deneye göre 0,66 ve 0.65 olarak tespit edildi düşük hız rüzgar tüneli ve Reynolds sayısı bağımsızlığı.

Anahtar Kelimeler

• Sürükle katsayısı,Reynolds sayısı,araç aerodinamik,sürükleme kuvveti,performans

Kaynakça

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