World Academy of Science, Engineering and Technology
Published May 20, 2011 | Version 11901
Journal article Open

Passive Flow Control in Twin Air-Intakes

Creators

Description

Aircraft propulsion systems often use Y-shaped subsonic diffusing ducts as twin air-intakes to supply the ambient air into the engine compressor for thrust generation. Due to space constraint, the diffusers need to be curved, which causes severe flow non-uniformity at the engine face. The present study attempt to control flow in a mild-curved Y-duct diffuser using trapezoidalshaped vortex generators (VG) attached on either both the sidewalls or top and bottom walls of the diffuser at the inflexion plane. A commercial computational fluid dynamics (CFD) code is modified and is used to simulate the effects of SVG in flow of a Y-duct diffuser. A few experiments are conducted for CFD code validation, while the rest are done computationally. The best combination of Yduct diffuser is found with VG-2 arranged in co-rotating sequence and attached to both the sidewalls, which ensures highest static pressure recovery, lowest total pressure loss, minimum flow distortion and less flow separation in Y-duct diffuser. The decrease in VG height while attached to top and bottom walls further improves axial flow uniformity at the diffuser outlet by a great margin as compared to the bare duct.

Files

11901.pdf

Files (434.6 kB)

Name Size Download all
md5:787e6b4199ea91ca41aa7bc42d71c547
434.6 kB Preview Download

Additional details

References

  • J. Seddon, and E. L. Goldsmith, Intake Aerodynamics, Collins Professional Books, London, 1985.
  • D. D. William, and L. E. Surber, Intake Engine Compatibility, In: Goldsmith, E.L., Seddon (Eds.), Practical Intake Aerodynamic Design, Blackwell Scientific Publications, Oxford, pp. 1993, 21-71.
  • J. C. Lin, G. V. Selvy, F. G. Howard, "Exploratory study on vortex generator devices for turbulent flow separation control", AIAA paper No. AIAA-91-0042, 1991.
  • B. A. Reichert, and B. J. Wendt, "Improving diffusing S-duct performance by secondary flow control" , NASA Technical Memorandum 106492, 1994.
  • R. K. Sullerey, S. Mishra, and A. M. Pradeep, "Application of boundary layer fences and vortex generators in improving performance of S-duct diffusers", ASME J. of Fluids Engineering, vol. 124, no. 3, pp. 136-142, 2002.
  • O. E. Abdellatif, "Experimental study of turbulent flow characteristics inside a rectangular S-shaped diffusing duct", AIAA paper No. AIAA- 2006-1501, 2006.
  • R. W. Fox, and S. J. Kline, "Flow regimes in curved subsonic diffusers", Journal of Basic Engineering, vol. 84, pp. 303-316, 1962.
  • K. A. Ahmad, J. K. Watterson, J. S. Cole, and I. Briggs, "Sub-boundary layer vortex generator control of a separated diffuser flow", AIAA paper No. 2005-4650, 2005.
  • A. R. Paul, K. Kuppa, M. S. Yadav, and U. Dutta, "Flow improvement in rectangular air-intake by submerged vortex generators, Journal of Applied Fluid Mechanics, vol. 4, no. 2, 2011 (to be published in July 2011). [10] S. B. Pope, Turbulent Flows, 6th Reprint, Cambridge Univ. Press, NY, 2009, pp. 373-384. [11] W. P. Jones, and B. E. Launder, "The prediction of laminarization with a two-equation model of turbulence", Int. J. of Heat and Mass Transfer, vol. 15, pp. 301-314, 1972. [12] B. E. Launder, and B. I. Sharma, "Application of the energy-dissipation model of turbulence to the calculation of flow near a spinning disc", Letters of Heat and Mass Transfer, vol. 1, pp. 131-138, 1974. [13] B. E. Launder, Phenomenological Modeling: Present... and Future?, In: J.L. Lumley (Ed.), Whither Turbulence? Turbulence at the Crossroads, Springer-Verlag, Berlin, 1990, pp. 439-485. [14] K. Hanjalić, "Advanced turbulence closure models: A view of current status and future prospects", J. of Heat and Fluid Flow, vol. 15, pp. 178- 203, 1994. [15] V. Yakhot, and S. A. Orszag, "Renormalized group analysis of turbulence: I. Basic theory", J. of Scientific Computation, vol. 1, 1986, pp. 3-51. [16] L. M. Smith, and W. C. Reynolds, "On the Yakhot-Orszag renormalization group method for deriving turbulence statistics and models", Physics of Fluids, vol. A4, pp. 364-390, 1992. [17] L. M. Smith, and S. L. Woodruff, "Renormalization-group analysis of turbulence", Annual Review of Fluid Mechanics, vol. 30, pp. 275-310, 1998. [18] S. A. Orszag, I. Staroselsky, W. S. Flannery and Y. Zhang, Introduction to renormalization group modeling of turbulence, In. T. B. Gatski, M. Y. Hussaini and J. L. Lumly (Eds.), Simulation and Modeling of Turbulent Flows, Oxford Univ. Press, NY, Chapter 4, 1996, pp. 155-183. [19] D. Choudhury, Introduction to the renormalization group method and turbulence modeling, Fluent Technical Memorandum 107, 1993, Lebanon, NH. [20] S. V. Patankar, Numerical Heat Transfer and Fluid Flow, Taylor and Francis Publication, London, 1980.