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

Year 2020, Volume: 40 Issue: 1, 77 - 86, 30.04.2020

Haci Soğukpınar , Serkan Çağ Bülent Yanıktepe

Abstract

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.

Keywords

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

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

Abstract

In this study, a non-slender simple delta wing was investigated numerically by using RANS with SST 𝑘−𝜔 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

References

• Canpolat C., Yayla S., Sahin B., Akilli H., 2011, Observation of the vortical flow over a yawed delta wing, Journal of Aerospace Engineering, 25(4), 613-626.
• Canpolat C., Yayla S., Sahin B., Akilli H., 2009, Dye visualization of the flow structure over a yawed nonslender delta wing. Journal of Aircraft, 46(5), 1818-1822.
• Cummings R.M., Morton S.A., Siegel S.G., 2008, Numerical prediction and wind tunnel experiment for a pitching unmanned combat air vehicle, Aerospace Science and Technology 12(5), 355-364.
• Cummings R.M., Schütte, A., 2013, Detached-Eddy Simulation of the vortical flow field about the VFE-2 delta wing, Aerospace Science and Technology, 24(1), 66-76.
• Elkhoury M., Yavuz M.M., and Rockwell D., 2005, Near-surface topology of unmanned combat air vehicle planform: Reynolds number dependence, Journal of aircraft 42(5), 1318-1330.
• Gordnier R.E., Visbal M.R., 2003, Higher-order compact difference scheme applied to the simulation of a low sweep delta wing flow, 41st AIAA Aerospace Sciences Meeting and Exhibit, 6–9 January, Reno, NV. AIAA 0620.
• Gursul I., Gordnier R., Visbal M., 2005, Unsteady aerodynamics of nonslender delta wings, Progress in Aerospace Sciences, 41(7), 515-557.
• Gülsaçan B., Şencan G., Yavuz, M.M., 2018, Effect of Thickness-to-Chord Ratio on Flow Structure of a Low Swept Delta Wing, AIAA Journal, 56(12), 4657-4668.
• Johnson F. T., Tinoco E. N., Yu, N. J., 2005, Thirty years of development and application of CFD at Boeing Commercial Airplanes, Computers & Fluids, 34(10), 1115-1151.
• Kyriakou M., Missirlis D., Yakinthos K., 2010, Numerical modeling of the vortex breakdown phenomenon on a delta wing with trailing-edge jet-flap, International Journal of Heat and Fluid Flow, 31(6), 1087-1095.
• Mary I., 2003, Large eddy simulation of vortex breakdown behind a delta wing. International journal of heat and fluid flow, 24(4), 596-605.
• Menter F.R., 1994, Two-Equation Eddy-Viscosity Turbulence Models for Engineering Applications, AIAA Journal, 32, 1598-1605.
• Muir R. E., Arredondo-Galeana A., Viola I.M., 2017, The leading-edge vortex of swift wing-shaped delta wings, Royal Society open science, 4(8), 1-14.
• OL M.V., Gharib M., 2003, Leading-edge vortex structure of nonslender delta wings at low Reynolds number, AIAA Journal, 41(1), 16–26.
• Saha S., and Majumdar B., 2012, Flow visualization and CFD simulation on 65 delta wing at subsonic condition, Procedia engineering, 38, 3086-3096.
• Sogukpinar H., 2019, Numerical Investigation of Influence of Diverse Winglet Configuration on Induced Drag, Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, 44, 203-215.
• Sogukpinar H., 2018, Low Speed Numerical Aerodynamic Analysis of New Designed 3D Transport Aircraft, International Journal of Engineering Technologies, 4(4), 153-160.
• Taylor G.S., Schnorbus T., Gursul I., 2003, An investigation of vortex flows over low sweep delta wings, AIAA Fluid Dynamics Conference, 23–26 June, Orlando FL, AIAA 4021, 1-13
• Wentz W.H., Kohlman D.L., 1971, Vortex breakdown on slender sharp-edged wings. Journal of Aircraft, 8(3), 156–61.
• Yayla S., Canpolat C., Sahin B., Akilli H., 2010, Elmas Kanat Modelinde Oluşan Girdap Cokmesine Sapma Acisinin Etkisi, Isi Bilimi ve Teknigi Dergisi/Journal of Thermal Science & Technology, 30(1),79-89.
• Yaniktepe B., and Rockwell D., 2004, Flow structure on a delta wing of low sweep angle, AIAA journal, 42(3), 513-523.
• Yavuz M., Elkhoury M., and Rockwell D., 2004, Near-Surface Topology and Flow Structure on a Delta Wing, IAA Journal, 42(2), 332–340.
• Internet, 2019, Pardiso Parallel Sparse Direct and Multi - Recursive Iterative Linear Solvers, User Guide Version 6.0, https://pardiso-project.org [accessed 20 February 2019].
• Internet, 2019, COMSOL CFD module user guide http://www.comsol.com, [accessed 20 February 2019].