S. Mano1, S. Arunvinthan1, and S. Nadaraja Pillai This email address is being protected from spambots. You need JavaScript enabled to view it.1

1School of Mechanical Engineering, SASTRA Deemed University, Thanjavur, Tamil Nadu, India


Received: November 19, 2019
Accepted: February 28, 2020
Publication Date: December 1, 2020

Download Citation: ||https://doi.org/10.6180/jase.202012_23(4).0004  


In recent times, air transport has emerged as an important force in driving the globalization process, resulting in an ever increasing passenger growth, which in turn demands reduced in-between timings of preceding flights. One of the prominent factors which influence this in-between timings is the downstream wake characteristics. Therefore, in this current study, a series of wind tunnel investigations were performed to assess the downstream near wake characteristics of the NACA 0015 airfoil at various angles of attack corresponding to Re =1.83×105. The downstream near wake measurements and turbulence quantities were measured using a Pitot-static probe and a simultaneous pressure scanner, with a sampling frequency of 700Hz. Experimental results revealed the complex nature of the downstream near wake characteristics featuring substantial asymmetry arising out of the incoherent flow separations prevailing over the suction and the pressure side of the airfoil. Aiming at systematically investigating the downstream near wake characteristics, the following parameters like wake width, dissipation length, wake width coefficient, downstream velocity ratio and turbulence intensities were considered in this study. Based on the experimental results, it is found that the wake width and the downstream velocity ratio decreases with the increase in the angle of attack. However, the dissipation length, wake width coefficient and turbulence intensity increase with the increase in the angle of attack. Additionally, attempts were made to understand the physical nature of the near wake characteristics at two and four axial chord downstream locations.

Keywords: wake velocity; dissipation length; downstream velocity ratio; wake width coefficient


  1. [1]IATA report based on 2017 data https://www.iata.org/pressroom/pr/Pages/2018-10-24-02.aspx.
  2. [2]Tony Diana, An evaluation of departure throughputs before and after the implementation of wake vortex re categorization at Atlanta Hartsfield/Jackson International Airport: A Markov regime-switching approach Transportation Research Part E: Logistics and Transportation Review 2015, Volume 83, Pages 216-224, ISSN 1366-5545,https://doi.org/10.1016/j.tre.2015.09.005.
  3. [3]Spalart P.R. 1998, Airplane trailing vortices, Annu. Rev. Fluid Mech. 30 (1998) 107–138.
  4. [4]Kopp F. 1994. Doppler Lidar investigation of wake vortes transport between closely spaced runways. AIAA J. 32(4):805–10.Foster, I., Kesselman, C.: The Grid: Blueprint for a New Computing Infrastructure. Mor¬gan Kaufmann, San Francisco (1999).
  5. [5]Rudis RP, Burnham DC, Janota P. 1996. Wake vortex decay near the ground under conditions of strong stratification and wind shear. Presented at Advis. Group Aerosp.
  6. [6]Lee GH. Trailing vortex wakes. Aeronaut. J. 79:377–88. 1975.
  7. [7]Garodz LJ, Clawson KL. 1993. Vortex wake characteristics of B757–200 and B767–200 aircraft using the tower fly-by technique. NOAA Tech. Mem. ERL.
  8. [8]Garodz LJ ,DM Lawrence and NJ Miller 1974, Measurement of the Trailing Vortex Systems of Large Transport Aircraft, Using Tower Fly-by and Flow Visualization (Summary, Comparison and Application).
  9. [9]De Bruin AC, Hegen SH, Rohne PB, Spalart PR. 1996. Flow field survey in trailing vortex system behind a civil aircraft model at high lift. Presented at Advis. Group Aerosp. Res. Dev. (AGARD) Symp., Trondheim, Norway, 25:1–1
  10. [10]Hallock J.N., Aircraft Wake Vortices: An Assessment of the Current Situation. Report No. DOT-FAA-RD-90–29, January 1991, p. 59.
  11. [11]Spalart PR, Wray AA. 1996. Initiation of the Crow instability by atmospheric turbulence. Presented at Advis. Group Aerosp. Res. Dev. (AGARD) Symp., Trondheim, Norway, 18:1–8.
  12. [12]Gerz T and Ehret T 1996. Wake dynamics and exhaust distribution behind cruising aircraft. Presented at Advis. Group Aerosp. Res. Dev. (AGARD) Symp., Trondheim, Norway, 1996. 35:1–12.
  13. [13]Thomas Gerz, Frank Holzäpfel, Denis Darracq 2002, Commercial aircraft wake vortices, Progress in Aerospace Sciences, Volume 38, Issue 3, Pages 181-208, ISSN 0376-0421, https://doi.org/10.1016/S0376-0421(02)00004-0.
  14. [14]Hallock J.N., G.C. Greene, D.C. Burnham 1998, Wake vortex research – A retrospective look, Air Traffic Contr. Q. 6 (3) 161–178. Dev. (AGARD) Symp., Trondheim, Norway, 11:1–10
  15. [15]Breitsamter C. 2011, Wake vortex characteristics of transport aircraft, Prog. Aero. Sci. 47 (2011) 89–134.
  16. [16]Wei Zhang, Wan Cheng, Wei Gao, Adnan Qamar, Ravi Samtaney, Geometrical effects on the airfoil flow separation and transition, Computers & Fluids, Volume 116,2015, Pages 60-73, ISSN 0045-7930, https://doi.org/10.1016/j.compfluid. (2015).
  17. [17]Hah C. and Lakshminarayana B 1982, Measurement and prediction of mean velocity and turbulence structure in the near wake of an airfoil, J. Fluid Mech. , vol. 115, pp. 261-282.
  18. [18]Balaji G. Nadaraja Pillai S. And Senthil Kumar C 2017. Wind Tunnel Investigation of Downstream Wake Characteristics on Circular Cylinder with Various Taper Ratios. Journal of Applied Fluid Mechanics, Vol. 10, Special Issue, pp. 69-77. ARL—199 Silver Spring, MD: Air Resources Lab.
  19. [19]Lung-Jieh Yang, Cheng-Kuei Hsu, Hsieh-Cheng Han and Jr-Ming Miao 2012, Light Flapping Micro Aerial Vehicle Using Electrical-Discharge Wire-Cutting Technique, 46, No .6, J. of Aircraft.


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