Investigation of the effect of turbulence models for CFD simulations of dynamic airfoils

Öz

This study presents a numerical investigation into the aerodynamic behavior of a pitching NACA 0012 airfoil under dynamic conditions. The analysis was carried out using a sliding mesh method in Fluent, incorporating sinusoidal pitching motion with various turbulence models, including SST, SST with intermittency, and Transition SST. The effects of different turbulence models on the aerodynamic performance of the airfoil at various angles of attack (AoA) were studied, focusing on the pressure coefficient (Cp), flow structure, and laminar separation bubble (LSB) formation. Additionally, the results for pitch-up and pitch-down motions were compared to evaluate the hysteresis effects and dynamic flow behaviors. The study found that the SST model exhibited inviscid flow characteristics, while the SST with intermittency and Transition SST models captured the boundary layer behavior more effectively, including the separation and reattachment processes. Significant differences were observed in the Cp distribution and turbulence characteristics, with pitch-down motion resulting in higher Cp values and more complex flow phenomena. The results contribute to the understanding of aerodynamic behavior during dynamic motions, offering insights into the role of turbulence models on airfoil performance.

Anahtar Kelimeler

• Pitching airfoil
• turbulence model
• pressure distribution
• sinusoidal motion

Dinamik kanat profilinin CFD simülasyonları için türbülans modellerinin etkisinin incelenmesi

Öz

Bu çalışma, dinamik koşullarda yunuslama hareketi yapan bir NACA 0012 kanat profilinin aerodinamik davranışına ilişkin sayısal bir araştırma sunmaktadır. Analiz, SST, SST- intermittency ve Transition SST dahil olmak üzere çeşitli türbülans modelleriyle sinüzoidal hareketini birleştiren Fluent'te kayan bir ağ yöntemi kullanılarak gerçekleştirilmiştir. Farklı türbülans modellerinin, çeşitli hücum açılarında kanat profilinin aerodinamik performansı üzerindeki etkileri, basınç katsayısı, akış yapısı ve laminer ayrılma kabarcığı oluşumuna odaklanılarak incelenmiştir. Ek olarak, yukarı ve aşağı hareketlerinin sonuçları, histerezis etkilerini ve dinamik akış davranışlarını değerlendirmek için karşılaştırılmıştır. Çalışma, SST modelinin görünmez akış karakteristikleri sergilediğini, SST- intermittency ve Transition SST modellerinin ise ayrılma ve yeniden bağlanma süreçleri dahil olmak üzere sınır tabakası davranışını daha etkili bir şekilde yakaladığını bulmuştur. Cp dağılımında ve türbülans özelliklerinde önemli farklılıklar gözlemlendi, aşağı yunuslama hareketi daha yüksek Cp değerleri ve daha karmaşık akış fenomenleriyle sonuçlandı. Sonuçlar dinamik hareketler sırasında aerodinamik davranışın anlaşılmasına katkıda bulunarak türbülans modellerinin rolü kanat profili performansı üzerindeki etkisi hakkında fikir vermiştir.

Anahtar Kelimeler

• yunuslayan kanat profili
• türbülans modeli
• basınç dağılımı
• sinüzoidal hareket

Kaynakça

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