Aerodynamic Characteristics of Semi-spiroid Winglets at Subsonic Speed
In recent years, owing to the improving global socio-economic conditions, the number of air passengers grows rapidly. Despite the phenomenal increase in the passenger growth, the airline fuel cost continues to dominate with 27% of the total airline operating cost. Induced drag due to the pressure differential induced between the wings being the major contributor accounts for 25% of total drag at cruise to around 60% during take-off. With a view to overcome this, end plates were introduced in the 1980s to reduce the wingtip vortices. Several studies have been performed by researchers over various configurations and found that the angle at which the winglets are inclined greatly influences the strength of the wingtip vortices shed away from the winglets. In order to understand the effect of eccentricity on aerodynamic performance, a baseline swept wing with vertical winglets and seven different modified models featuring curved winglets with different eccentricities were computationally investigated for various angles of attack at Re = 4.0 × 106. Results reveal that the curved semi-spiroid winglet with eccentricity e (0.2) outperforms clean wing showing a 9.85% increment in the aerodynamic efficiency over the pre-stall regions.
KeywordsSpiroid winglets Eccentricity Induced drag CFD
Funding: This work was supported by “Research and Modernization fund, SASTRA University” grant number R&M/0035/SoME-008/2015-16. The authors thank SASTRA University for their financial assistance.
- 1.IATA: Annual review (2016)Google Scholar
- 2.Anderson, J.D.: Fundamentals of Aerodynamics. McGraw–Hill, New York (2011)Google Scholar
- 3.Whitcomb, R.T.: A design approach and selected wind-tunnel results at high subsonic speeds for wing-tip mounted winglets. NASA Technical Note, NASA TN D-8260, July 1976Google Scholar
- 4.Chambers, J.R.: Concept to Reality: Contributions of the NASA Langley Research Center to US Civil Aircraft of the 1990s. NASA SP-2003-4539 (2003)Google Scholar
- 6.Falcão, L., Gomes, A., Suleman, A.: Design and analysis of an adaptive wingtip. In: 19th AIAA/ASME/AHS Adaptive Structures Conference, Denver, CO, USA, pp. 1–13 (2011)Google Scholar
- 7.Soltani, M.R., Ghorbanian, K., Nazarinia, M.: Experimental investigation of the effect of various winglet shapes on the total pressure distribution behind a wing. In: Proceeding of the 24th International Council of the Aeronautical Sciences, Yokohama, Japan (2004)Google Scholar
- 9.Air Force Studies Board Division on Engineering and Physical Sciences: Assessment of Wingtip Modifications to Increase the Fuel Efficiency of Air Force Aircraft. Committee on Assessment of Aircraft Winglets for Large Aircraft Fuel Efficiency. The National Academies Press (2007)Google Scholar
- 10.Jackson, P., et al.: Jane’s all the World’s Aircraft. Jane’s Information Group (2004)Google Scholar
- 13.Bardina, J.E., Huang, P.G., Coakley, T.J.: Turbulence modeling validation, testing, and development. NASA Technical Memorandum 11044 (1997)Google Scholar