Passive flow control around the airfoil with slot
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Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Adana Alparslan Türkeş Bilim ve Teknoloji Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu tez çalışmasında, NACA 0018 kanat profili etrafındaki akışın yarık ile kontrol edilmesinin değişken hücum açılarında sayısal analizi yapılmıştır. Reynolds sayısı Re=3x10^5 olarak belirlenmiştir. Yarık girişi kanat profilinin basınç tarafında veter uzunluğuna göre x/c=%5'lik kısmında konumlandırılırken, yarık çıkışı kanat profilinin emme tarafında üç farklı lokasyonda konumlandırılmıştır. Sayısal analizler, K-? SST ve K-? RNG olmak üzere iki farklı türbülans modeli kullanılarak gerçekleştirilmiştir. Sayısal analizlerden elde edilen sonuçlar, yarığın akış yapısı ve aerodinamik kuvvetler üzerindeki etkisi açısından değerlendirilmiştir. Yarığın konumunun, kanat profili üzerindeki akışı önemli ölçüde etkilediği gözlenmiştir. Model 40'ın, kanat profili üzerinde oluşan dolanımlı bölgesinin oluşumunu engellediği gözlemlenmiştir. Ayrıca yarıksız kanadın stall açısı ?=16° iken Model 40 modelinin bu açıyı ?=20°'ye kadar ötelediği gözlemlenmiştir. Ayrıca Model 40'ın ?=19° hücum açısında kaldırma katsayısını %154 arttığı gözlemlenmiştir. Öte yandan Model 20'nin ? ?13° hücum açılarında yarıksız kanat profiline göre akış kontrolü üzerinde önemli ölçüde etkili olduğu, düşük hücum açılarında ise önemsiz bir etkiye sahip olduğu görülmüştür. Düşük hücum açılarında Model 60 için de benzer sonuçlar elde edilmiştir. Her iki türbülans modelinden elde edilen sonuçlara göre, özellikle stall açılarında kanat etrafındaki akışı kontrol etmek için en etkili modelin Model 40 olduğu gözlemlenmiştir.
In this thesis, numerical analysis was performed to control of flow over NACA 0018 airfoil with slot at variant angles of attack. The Reynolds number was set to Re=3x10^5. Inlet of slot was posiniated on the pressure side of airfoil at chordwise location of x/c=5% while outlet of slot was located on the suction side of airfoil at three different chordwise location. Numerical analyzes were carried out using two different turbulence models, K-? SST and K-? RNG. Obtained results from the numerical analyzes were evaluated in terms of effect of the slot on flow structure and aerodynamic forces. It was observed that the location of slot remarkably affect flow over airfoil and delays stall angle. The model 40 suppress the formation of recirculation region formed over the airfoil. Furthermore, it was observed that while the stall angle of base airfoil is ?=16°, it was delayed up to ?=20° for Model 40. Also, it was observed that the lift coefficient was increased by 154% for Model 40 at ?=19°. On the other hand, it was observed that Model 20 significantly effective on the flow control in comparison with the base airfoil at angles of attack of ? ?13°, while it has insignificant effect at low angles of attack. Similar observation was also obtained for Model 60 at low angles of attack. According to obtained results from both turbulence models, the most efficient model was determined as Model 40 in order to control flow around the airfoil especially for post stall angles.
In this thesis, numerical analysis was performed to control of flow over NACA 0018 airfoil with slot at variant angles of attack. The Reynolds number was set to Re=3x10^5. Inlet of slot was posiniated on the pressure side of airfoil at chordwise location of x/c=5% while outlet of slot was located on the suction side of airfoil at three different chordwise location. Numerical analyzes were carried out using two different turbulence models, K-? SST and K-? RNG. Obtained results from the numerical analyzes were evaluated in terms of effect of the slot on flow structure and aerodynamic forces. It was observed that the location of slot remarkably affect flow over airfoil and delays stall angle. The model 40 suppress the formation of recirculation region formed over the airfoil. Furthermore, it was observed that while the stall angle of base airfoil is ?=16°, it was delayed up to ?=20° for Model 40. Also, it was observed that the lift coefficient was increased by 154% for Model 40 at ?=19°. On the other hand, it was observed that Model 20 significantly effective on the flow control in comparison with the base airfoil at angles of attack of ? ?13°, while it has insignificant effect at low angles of attack. Similar observation was also obtained for Model 60 at low angles of attack. According to obtained results from both turbulence models, the most efficient model was determined as Model 40 in order to control flow around the airfoil especially for post stall angles.
Açıklama
Fen Bilimleri Enstitüsü, Havacılık ve Uzay Mühendisliği Ana Bilim Dalı
Anahtar Kelimeler
Havacılık ve Uzay Mühendisliği, Aeronautical Engineering
