F35 Savaş Uçağının Deneysel ve Nümerik Yöntemlerle İncelenmesi
Bu makalede, orijinal F35 uçak modelinin düşük hızda aerodinamik akış yapısı kapalı devre su tüneli deneyinde araştırılmış ve ayrıca hesaplamalı akışkanlar dinamiği (CFD) yaklaşımı kullanılarak sayısal olarak incelenmiştir. Her iki çalışma için, kiriş uzunluğu c = 168 mm, kanat geri süpürme açısı Λ = 21.59°, pah açısı 45°, et kalınlığı 5 mm, Reynolds sayısı 10.000 ve akış hızı 0,6 cm/s olan parametreler kullanılarak 5°-25° aralığındaki hücum açıları için araştırma yapılmıştır. Deneysel kısım için boya görselleştirme deneyi ve parçacık görüntü hız ölçümü (PIV) deneyleri yapılmış, nümerik yöntem olarak SST türbülans modeli kullanılmıştır, elde edilen veriler deneysel ve nümerik sonuçlarla kıyaslanmıştır. Ön kenar girdabının oluşması ve girdap dağılması/çökmesi ve akış alanı ile ilgili etkileşimler araştırılmış ve elde edilen veriler tartışılmıştır. Ön kenar girdap oluşumu 5°’de kısmen başlamış, 10°’de girdap kırılması belirginleşmiş ve hücum açısının artmasına bağlı olarak girdap çökme noktası ön tarafa doğru ilerlemiştir. 25°’lik hücum açısına gelindiğinde girdap çökme/dağılma noktası tepe noktasına kadar ilerlememiş, kanat üzerinde kalmış, uçağın bütünüyle stol’a girme durumu gözlemlenmemiştir. Anahtar Kelimeler: F35 savaş uçağı; LEV; Girdap çökmesi; Girdap; PIV; Boya görüntüleme.
Numerical Investigation and Water Tunnel Experiment for F35 Fighter Jet
In this paper, a low-speed aerodynamic flow structure of the original F35 aircraft model was investigated in a closed-circuit water tunnel experiment, and the investigation was also conducted numerically by using a computational fluid dynamic (CFD) approach. Both studies were performed for the model with a chord length of c =168 mm and wing sweepback angle of Λ = 21.59°, thickness 5 mm and beveled leading edges with an angle of 45°, and for the Reynolds numbers 10.000 at the angle of attack from 5° to 25° with the airflow speed of 0.6 cm/s. For the experimental part, dye visualization and Particle Image Velocimetry (PIV) experiments were performed, and for the numerical part, SST turbulence model was used to solve the flow field around model aircraft and obtained data were compared with experiment. Detail about the flow field including, the development of leading-edge vortex and formation of vortex breakdown and interactions were discussed and presented. Leading-edge vortices were partially developed at the angle of 5°, vortex breakdown pronounced at the angle of 10°, as the increasing angle of attack, location of vortex breakdown moved further up to the front side. At 25°, there was no complete stall condition, and the location of the vortex breakdown stayed on the wing surface. Keywords: F35 fighter jet; LEV; Vortex breakdown; Vorticity; PIV; Dye visualization.
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- Waldmann, A., Unsteady wake flow analysis of an aircraft under low-speed stall conditions using DES and PIV, In 53rd AIAA Aerospace Sciences Meeting, 1096, 2015.
- Yokokawa, Y., Murayama, M., Ito, T., Yamamoto, K., Experiment and CFD of a highlift configuration civil transport aircraft model, In 25th AIAA aerodynamic measurement technology and ground testing conference, 3452, 2006.
- Johnson, F.T., Tinoco, E.N., Yu, N.J., Thirty years of development and application of CFD at Boeing Commercial Airplanes, Seattle, Computers & Fluids, 34(10), 1115-1151, 2005.
- Sogukpinar, H., Numerical investigation of influence of diverse winglet configuration on induced drag, Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, 44, 1-13, 2019.
- Gursul, I., Gordnier, R., Visbal, M., Unsteady aerodynamics of nonslender delta wings, Progress in Aerospace Sciences, 41(7), 515-557, 2005.
- Canpolat, C., Yayla, S., Sahin, B., Akilli, H., Dye visualization of the flow structure over a yawed nonslender delta wing, Journal of Aircraft, 46(5), 1818-1822, 2009.
- Muir, R.E., Arredondo-Galeana, A., Viola, I.M., The leading-edge vortex of swift wingshaped delta wings, Royal Society Open Science, 4(8), 170077, 2017.
- Jardin, T., David, L., Spanwise gradients in flow speed help stabilize leading-edge vortices on revolving wings, Physical Review E, 90(1), 013011, 2014.
- Yaniktepe, B., Rockwell, D., Flow structure on diamond and lambda planforms: Trailing-edge region, AIAA journal, 43(7), 1490-1500, 2005.
- Yaniktepe, B., Ozalp, C., Canpolat, C., Aerodynamics and flow characteristics of X45 delta wing planform, Kahramanmaras Sutcu Imam University Journal of Engineering Sciences, 19(1), 1-10, 2016.
- Canpolat, C., Yayla S., Sahin, B., Akilli, H., Observation of the Vortical Flow over a Yawed Delta Wing, Journal of Aerospace Engineering, 25, 613-626, 2012.
- Watanabe, S., Kato, H., Stereo PIV applications to large-scale low-speed wind tunnels, In 41st Aerospace Sciences Meeting and Exhibit, 919, 2003.
- Watanabe, S., Mungal, M.G., Velocity field measurements of mixing-enhanced compressible shear layers, AIAA, 99-0088, 1999.
- Humphreys, W.M., A survey of particle image velocimetry applications in Langley Aerospace Facilities, AIAA Paper, 93-0411, 1993.
- Wiegand, C., F-35 Air vehicle technology overview, 2018 Aviation Technology, Integration, and Operations Conference, 1-28, 2018.
- Raffel, M., Willert, C.E., Wereley, S.T., Kompenhans, J., Particle image velocimetry: A practical guide, 2nd ed., Springer, 2007.
- Arroyo, M.P., Greated, C.A., Stereoscopic particle image velocimetry, Measurement Science & Technology, 2(12), 1181-1186, 1991.
- Westerweel, J., Digital particle image velocimetry, Theory and Application, Delft University Press, 1993.
- Adrian, R.J., Twenty years of particle image velocimetry, Experimental Fluids, 39, 159–169, 2005.
- Raffel, M., Willert, C.E., Wereley, S.T., Kompenhans, J., Particle image velocimetry: A practical guide, 2nd ed., Springer, 2007.
- Menter, F.R., Two-equation Eddy-viscosity turbulence models for engineering applications, AIAA Journal, 32(8), 1598-1605, 1994.
- Menter, F.R., Kuntz, M., Langtry, R., Ten years of ındustrial experience with the SST turbulence model, Turbulence Heat and Mass Transfer, 4, 625-632, 2003.
- COMSOL CFD Module user guide, http://www.comsol.com (Accessed on April 8, 2019).
- Fontes, E., Using the algebraic multigrid (AMG) method for large CFD simulations, https://www.comsol.com (Accessed on April 8, 2019).
- Sogukpinar, H., Effect of hairy surface on heat production and thermal insulation on the building, Environmental Progress & Sustainable Energy, e13435, 1-8, 2020.
- Cummings, R.M., Scott, A.M., and Stefan, G.S., Numerical prediction and wind tunnel experiment for a pitching unmanned combat air vehicle, Aerospace Science and Technology, 12(5), 355-364, 2008.
- Sogukpinar, H., Low speed numerical aerodynamic analysis of new designed 3D transport aircraft, International Journal of Engineering Technologies, 4(4), 153-160, 2019.
- Sogukpinar, H., Numerical calculation of wind tip vortex formation for different wingtip devices, INCAS Bulletin, 10(3), 167-176, 2018.