S809 Kanat Profili Etrafındaki Sınır Tabaka Akışının Emme Tekniği ile Aktif Kontrolünün Sayısal İncelenmesi

Year 2020, , 461 - 472, 28.06.2020

Gurbet Çankaya , Onur Erkan , Musa Özkan

https://doi.org/10.35193/bseufbd.729822

Abstract

Bu çalışmada, sınır tabaka akışı aktif kontrol yöntemlerinden biri olan, sınır tabakadan kanat içerisine hava emilmesi prensibine dayanan emme tekniği kullanılarak bir rüzgar türbini kanadının aerodinamik performansının arttırılması hedeflenmiştir. Emme işlemi daimi bir jet vasıtasıyla gerçekleştirilmiş, kanat modeli olarak rüzgar türbini uygulamalarında yaygın olarak kullanılan S809 kanat profili tercih edilmiştir. Çalışma parametreleri olarak, üç ayrı jet konumu (Ljet = 0.1c, 0.26c, 0.36c) ve üç ayrı jet oranı (Rjet = 0.1, 0.3, 0.5) seçilmiştir. Emme jeti genişliği sabit olup veter uzunluğunun %2.5’i kadar ve emme jeti açısı (θjet) bölgesel jet yüzeyine 90° olacak şekilde ayarlanmıştır. İki boyutlu türbülanslı akış için sayısal analiz; α = 15° hücum açısında ve Re = 106’da SST k-ω türbülans modeli kullanılarak gerçekleştirilmiştir. İlk olarak emme jeti konumunun etkisi, ardından en iyi sonucu veren emme jeti konumu seçilerek emme jeti oranının etkisi araştırılmıştır. Kanat profili etrafındaki akışa ait simülasyon sonuçları incelendiğinde, en iyi sonuç emme jeti konumu 0.36c (Jet-3) ve emme jeti oranı 0.5 olduğunda alınmıştır. Jet kullanılmadığı duruma göre CL/CD oranı 17.92’den 273.03’e yükselmiştir. Emme jeti ile kontrol yönteminin uygulanması ile kontrolsüz duruma göre Cl değeri yaklaşık olarak 1.211’den 1.8’e yükselmiş, Cd değeri ise 0.068’den 0.0066’ya düşmüştür.

Keywords

Aktif kontrol yöntemi, Emme jeti, S809 kanat profili, Sınır tabaka akışı

Numerical Investigation of Active Control of Boundary Layer Flow Around S809 Airfoil with Suction Method

Abstract

In this study, it is aimed to increase the aerodynamic performance of a wind turbine blade by using the suction technique which is one of the active control methods of boundary layer flows based on the principle of air intake from the boundary layer into the blade. Suction is defined as a continuous jet and the S809 airfoil is preferred which is widely used in wind turbine applications as a blade model. Three different jet positions (Ljet = 0.1c, 0.26c, 0.36c) and three different jet ratios (Rjet = 0.1, 0.3, 0.5) are selected as study parameters. The suction jet width is fixed and is 2.5% of chord length and the suction jet angle (θjet) is 90° to the local jet surface. Numerical analysis for a two-dimensional turbulent flow is performed using SST k-ω turbulence model with an angle of attack of α =15° and Re=106. Firstly, the effect of the suction jet position is investigated and then the effect of the suction jet ratio is examined with an optimum suction jet position that showed the best result. When the simulation results of the flow around the airfoil are examined, the best result is obtained when the suction jet position is jet-3 (0.36c) and the suction jet ratio is 0.5. CL/CD ratio is increased from 17.92 to 273.03 compared to the no-jet situation. By the application of the suction jet control method, the CL is increased approximately from 1.211 to 1.8 and the CD is decreased from 0.068 to 0.0066 in comparison to the uncontrolled case.

Keywords

Active control method, Suction jet, S809 airfoil, Boundary layer flow

References

• Yousefi, K., Saleh, S. R., & Zahedi, P. (2013). Numerical investigation of suction and length of suction jet on aerodynamic characteristics of the NACA 0012 airfoil. International Journal of Materials, Mechanics and Manufacturing, 1(2), 136-142.
• Kang, T. J., & Park, W. G. (2013). Numerical investigation of active control for an S809 wind turbine airfoil. International Journal of Precision Engineering and Manufacturing, 14(6), 1037-1041.
• Hassan, A. (2006). A two-point active flow control strategy for improved airfoil stall/post-stall aerodynamics. In 44th AIAA Aerospace Sciences Meeting and Exhibit (p. 99).
• Genç, M. S., & Kaynak, Ü. (2009). Control of laminar separation bubble over a NACA2415 aerofoil at low re transitional flow using blowing/suction. In International Conference on Aerospace Sciences and Aviation Technology (Vol. 13, No. Aerospace Sciences and Aviation Technology, ASAT-13, May 26–28, 2009, pp. 1-17). The Military Technical College.
• Liu, P. Q., Duan, H. S., Chen, J. Z., & He, Y. W. (2010). Numerical study of suction-blowing flow control technology for an airfoil. Journal of aircraft, 47(1), 229-239.
• Wilcox, D.C. (2004). Turbulence modelling for CFD, 2nd Edition, DCW Industries, Inc., ISBN 1-928729-10-X.
• Pehlivanoğlu, Y. V., Yağız, B., Kandil, O., & Baysal, O. (2010). Particle swarm optimization of suction and blowing on airfoils at transonic speeds. Journal of aircraft, 47(6), 1955-1965.
• Goodarzi, M., Rahimi, M., & Fereidouni, R. (2012). Investigation of active flow control over NACA0015 airfoil via blowing. International Journal of Aerospace Sciences, 1(4), 57-63.
• Menter, F.R. (1994). Two-equation eddy-viscosity turbulence models for engineering applications. AIAA Journal, 32(8), 1598-1605.
• Azim, R., Hasan, M. M., & Ali, M. (2015). Numerical investigation on the delay of boundary layer separation by suction for NACA 4412. Procedia Engineering, 105, 329-334.
• Shi, Y., Bai, J., Hua, J., & Yang, T. (2015). Numerical analysis and optimization of boundary layer suction on airfoils. Chinese Journal of Aeronautics, 28(2), 357-367.
• Langtry, R.B., & Menter, F.R. (2009). Correlation-based transition modeling for unstructured parallelized computational fluid dynamics codes. AIAA Journal, 47(12), 2894-2906.
• Douvi, E. C., & Margaris, D. P. (2012). Aerodynamic Characteristics of S809 vs. NACA 0012 Airfoil for Wind Turbine Applications. In Proceedings of the 5th International Conference from Scientific Computing to Computational Engineering, 5th IC-SCCE, Athens Greece, 4-7 July.
• Airfoil Tools, http://airfoiltools.com/airfoil/details?airfoil=s809-nr, (23.04.2020).
• Erkan, O. & Özkan, M. (2020). Investigation of the flow over NACA 63-415 airfoil. Black Sea Journal of Engineering and Science, 3(2), 50-56.
• Özkan, M., Thomas, P. J., Cooper, A. J., & Garrett, S. J. (2016). Comparison of the effects of surface roughness and confinement on rotor-stator cavity flow. Engineering Applications of Computational Fluid Mechanics, 11(1), 142-158.
• Ramsay, R. F., Hoffman, M. J., & Gregorek, G. M. (1995). Effects of grit roughness and pitch oscillations on the S809 airfoil (No. NREL/TP-442-7817). National Renewable Energy Lab., Golden, CO (United States).