Modern fighter jets are some of the most sophisticated and complex machines ever built and understanding their aerodynamic behavior is of great interest to improve flying performance and cost reduction design. The present study was devised to analyze the characteristics that fighter jets’ wings experience when flying at subsonic and supersonic conditions. This study was divided into two parts, as follows:
The first part of this study investigated the vortex formation on a 65-degree delta wing with a blunt leading edge at subsonic conditions. To this effect, a NASA’s wind tunnel experiment done to this same wing configuration in the Langley National Transonic Facility (NTF) was used as a reference to perform a numerical study using computational fluid dynamic techniques. Later, both results, the experimental and the numerical analysis were compared to validate the CFD techniques employed to apply these CFD procedures to a full-scale J-31 jet fighter.
Upon completion of the first case, CFD techniques were employed to analyze the aerodynamic characteristics encountered on a J-31 jet fighter when flying at 1.2 Mach including vortex formation and shock waves by analyzing its lift, drag, and pressure coefficient.

[1] D. Ahlmark, "Trajectory Optimization for Aircraft Evasive Maneuvering," Royal Institute of Technology, Stockholm, 2017.
[2] R. L. Hanson, "Evolution of Modern Dogfigh," Air Commanad and Staff College Air University, Alabama, 1987.
[3] P. S. Meilinger, "Supremacy in the Skies," Lt. Gen. (Ret.) Bruce "Orville" Wright, 2016.
[4] T. Naegele, "Agile Fighter Development," Lt. Gen. (Ret.) Bruce "Orville" Wright, 2019.
[5] C. L. Johnson, "Airplane Configurations for High-Speed Flight," SAE Transactions, vol. 62, p. 163–172, 1954.
[6] J. Chambers and S. Grafton, "Aerodynamic Charactheristics of Airplanes at High Angles of Attack," in AGARD/VKI Lecture Series on Aerodynamic Inputs for Problems in Aircraft Dynamics, Belgium, 1977.
[7] R. P. Hallion, "Remembering the Legacy: Highlights of the First 100 Years," The Bridge, vol. 34, no. 1, p. 5, 2014.
[8] Science Learning Hub – Pokapū Akoranga Pūtaiao, "A Progression of Flight," 9 September 2011. [Online]. Available: https://www.sciencelearn.org.nz/resources/1691-a-progression-of-flight-timeline. [Accessed 10 March 2019].
[9] D. L. Haulman, One Hundred Years of Flight: USAF Chronology of Significant Air and Space Events 1903-2002, Montgomery: Air University Press, 2003.
[10] A. J. Hebert, "Fighter Generations," Air Force Magazine, p. 32, September 2008.
[11] Air Power Development Centre, "Five Generations of Jet Aircraft," Pathfinder: Airpower Development Centre Bulletin, no. 170, January 2012.
[12] Fighter World Aviation Museum , "Five Generations of Jet," RAAF Base, Williamtown.
[13] J. A. Tirpak, "The Sixth Generation Fighter," Lt. Gen. (Ret.) Bruce "Orville" Wright, 2009.
[14] C. G. Grey and L. Bridgman, "Jane's All the World's Aircraft 1938," Jane's All the World's Aircraft, no. 2O, 1938.
[15] N. Wolchover, "How Do Stealth Planes Evade the Enemy?," Live Science, 2011.
[16] P. E. Illman, The Pilot's Handbook of Aeronautical Knowledge, Oklahoma City: McGraw-Hill Education, 1999.
[17] O. Maurer, "Supersonic Speed Through Swept Wings," ARTS Blog & Press, 07 03 2017. [Online]. Available: https://arts.eu/blog/blog-3/post/supersonic-speed-through-swept-wings-53. [Accessed 12 March 2019].
[18] J. D. Anderson, "Historical Note: The Origin of the Swept-Wings Concept," in Fundamentals of Aerodynamics, New York, McGraw-Hill, 2011, pp. 784-785.
[19] L. K. Loftin Jr., Quest for Performance: The Evolution of Modern Aircraft, Washington D.C.: CreateSpace Independent Publishing Platform, 2014.
[20] S. Corda, "Delta Wings," in Introduction to Aerospace Engineering with a Flight Test Perspective , West Sussex, John Wiley & Sons, 2017, pp. 408-409.
[21] E. C. Polhamus, "A Concept of the Vortex Lift of Sharp-Edge Delta Wings Based on a Leading-Edge-Suction Analogy," NASA, Hampton, 1966.
[22] J. M. Luckring, "A Survey of Factors Affecting Blunt-Leading Edge Separation for Swept and Semi Slender Wings," in AIAA 28th Applied Aerodynamics Conference, Chicago, 2010.
[23] J. M. Luckring, "Reynolds Number, Comprensibility, and Leading Edge Bluntess Effect on Delta Wing Aerodynamics," in 24th International Congress of the Aeronautical Sciences , Hampton, 2004.
[24] J. Anderson, in Computational Fluid Dynamics. The Basic with Applications, New York, McGraw-Hill , 1995.
[25] J. D. Anderson, Hypersonic and High Temperature Gas Dynamics, Washington DC: AIAA, 2006.
[26] A. R. Choudhuri, "The Physics of Fluids and Plasma," Bengaluru.
[27] M. H. Sadraey, Aircraft Design: A System of Engineering Approach, West Sussex : John Wiley & Sons, 2013.
[28] S. Desai, "Relative Roles of Computational Fluid Dynamics and Wint Tunnel Testing in the Development of Aircraft," Current Science, vol. 84, no. 1, pp. 49-64, 2003.
[29] J. Wendt, Computational Fluid Dynamics: An Introduction, Berlin: Springer, 2009.
[30] C. Carnagio, "CFD-RANS Study of horizontal axis wind turbines," Dipartimento di Ingegneria Meccanica, Universita degli Studi di Cagliari, Clagiari, 2008.
[31] CD-adapco, "STAR-CCM+ v.11.04 Product Overview," 2016.
[32] H. Peiris, P. Nirmal, H. Bandara, D. Mahindarathne, S. Rangajeeva and R. Bandara, "Aerodynamics Analysis of F-16 Aircraft," in 8th IEA International Research Conference, Sri Lanka, 2015.
[33] F. R. Menter, "Zonal Two Equation k-[omega] Turbulence Models for Aerodynamics Flows," in 24th Fluid Dynamics Conference, Orlando, 1993.
[34] M. Pavlovich and P. Victorovich, "Comparison of Turbulence Models in the Calculation of Surpersonic Separated Flows," World Applied Science Journal , vol. 27, no. 10, pp. 1263-1266, 2013.
[35] F. Menter, "Two-Equation Eddy-Viscosity Turbulence Models for Engineering Applications," AIAA, vol. 32, no. 8, pp. 1598-1605, 1994.
[36] J. Chu and J. M. Luckring, Experimental Surface Pessure Data Obtained on 65 Delta Wing Across Reynolds Number and Mach Number Ranges, Hampton: National Aeronautics and Space Administration, 1996.
[37] S. Crippa, "Advances in Vortical Flows Predictions Methods for Design of Delta Wing Aircraft," KTH Engineering Sciences, Stockholm, 2008.
[38] A. F. Tehcnology, "Air Force Technology," Air Force Technology , 27 November 2011. [Online]. Available: https://www.airforce-technology.com/projects/shenyang-j-31-stealth-fighter/. [Accessed 15 March 2019].
[39] M. Weisgerber, "China’s Copycat Jet Raises Questions About F-35," Defense One, 23 September 2015. [Online]. Available: https://www.defenseone.com/threats/2015/09/more-questions-f-35-after-new-specs-chinas-copycat/121859/. [Accessed 15 March 2019].