Haci SOĞUKPINAR, Serkan ÇAĞ, Bülent YANIKTEPE

HESAPLAMALI AKIŞKANLAR DİNAMİĞİ KULLANILARAK BASİT ÜÇGEN KANAT MODELİNDE YAKIN YÜZEY AKIŞ YAPISININ İNCELENMESİ

Bu çalışmada, düşük süpürme açısına sahip basit üçgen kanat modeli RANS denklemleri kullanılarak SST k-ω türbülans modeli ile incelenmiş, elde edilen bulgular daha önceden yapılmış deneysel verilerle kıyaslanarak Hesaplamalı Akışkanlar Dinamiğinin (HAD) tutarlılığı doğrulanmaya çalışılmıştır. Bu çalışma için, kiriş uzunluğu 101,6 mm, kanat genişliği 254 mm, et kalınlığı 3 mm, pah açısı 30°, ve süpürme açısı 40° olan üçgen kanat modellenmiştir. Hücum açısının (5 dereceden 17 dereceye kadar) kanat yüzeyi üzerindeki akış yapısına etkisi ve girdap çökmesi, hem üst plan hem de arka plan görüntüsü açısından Reynolds sayısı 10.000’de sabit tutularak incelenmiştir. Kıvrımlı, hücum kenar yanal girdap oluşumu 5 derecede başlamış, girdap çökmesi ilk defa 7 derecelik hücum açısında kanadın arka kısmında oluşmuş ve 10 derecede kanadın ön tarafına (x/c=0.5) doğru ilerlemiştir. Hücum açısı artıkça girdap çökmesi kanadın ön uç kısmına ilerlemiş, yaklaşık 17 derecede akış stol olmuştur.

Anahtar Kelimeler:

LEV, CFD, SST, üçgen kanat, girdap, hücum kenar yanal girdap

CFD INVESTIGATION OF THE NEAR-SURFACE STREAMLINE TOPOLOGY ON A SIMPLE NONSLENDER DELTA WING

In this study, a non-slender simple delta wing was investigated numerically by using RANS with SST ?−? turbulence model and the results were compared with experimental data to validate the simulation accuracy of the Computational Fluid Dynamics (CFD) approach. The delta wing configuration has a straight wing, with thickness 3 mm, chord length 101.6 mm, wingspan 254 mm, 30° beveled angle, and 40° sweep leading edge. Effect of angle of attack on the near-surface patterns of the delta wing was interpreted in terms of streamline topology, particularly bifurcation lines, as well as contours of streamwise and transverse velocity components, and also vorticity contours on the surface at the angle of attack starting from 5° to 17° with Reynolds number of 1x104. The leading-edge vortices (LEV) developed at the angle of 5°, the vortex breakdown happened first time at the angle of 7° and moved upstream direction and reached around x=0.5c at 10°. With the increasing angle of attack further, vortex breakdown moved to upstream a substantial distance and finally, the stall occurred at an angle of attack at 17°.

Keywords:

LEV, CFD, SST, delta wing, vorticity, leading-edge vortices,

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