The effect of nozzle outlet diameter of a single-spool, mixed-flow turbofan engine on its performance

Document Type : Original Article

Authors

1 BSc., Faculty of Renewable Energies, Urmia University of Technology, Urmia, Iran

2 Assistant Prof., Faculty of Renewable Energies, Urmia University of Technology, Urmia, Iran

10.22034/joae.2023.364648.1137

Abstract

Thrust and specific fuel consumption are two essential parameters in a gas turbine engine. The fundamental design of various engine components is required to enhance thrust and provide optimum specific fuel consumption. This paper studies the effects of the nozzle exit area on the operating lines of fan, compressor, and turbine in a single-spool, mixed-flow, and low bypass ratio turbofan engine. The zero-dimensional modeling of the engine is examined in GasTurb, and the nozzle area is changed in 6 cases by ±5, ±10, and ±15 percent relative to design point. The inlet temperature of turbine rotor and the spool speed of the engine are limited to their maximum amount. The results show that any change in the nozzle exit area will reduce the net thrust of the engine. On the other hand, with the reduction of the nozzle area, the operating line of the fan and compressor becomes closer to the surge line, reducing the surge margin, while with the increase of the nozzle area, the surge margin of the fan and compressor increases. Also, the changes in specific fuel consumption are inversely proportional to the changes in the nozzle outlet area.

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  • [1] A. F. ElSayed, Aircraft Propulsion and Gas Turbine Engines, 2th ed. Boca Raton: CRC Press, 2008.
  • [2] H. Gong, "Numerical study of jet noise generated by turbofan engine nozzles equipped with internal forced lobed mixers using the lattice boltzmann method", M.S. thesis, Dept. Mech. Eng., McGill Univ., Montreal, Canada, 2013.
  • [3] J. Kurzke and I. Halliwell, Propulsion and Power (An Exploration of Gas Turbine Performance Modeling): Springer, 2018.
  • [4] J. Wachter and F. Ko¨ pf, "Advanced Exhaust Performance Modelling of Mixed Turbofan Engines: Less is More," in Turbo Expo: Power for Land, Sea, and Air 2009, Vol. 48821, pp. 155-164.
  • [5] M. UIF, "The benefits of variable area fan nozzles on turbofan engines," in 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011, pp. 226.
  • [6] B. Sankar, G. Gouda, V. Iyengar and J. Soumendu, "Study of design modification effects through performance analysis of a legacy gas turbine engine," Journal of Aerospace Technology and Management, Vol. 12, 2020.
  • [7] R. H. Sundararaj, T. C. Sekar, R. Arora and A. Kushari, "Effect of nozzle exit area on the performance of a turbojet engine," Aerospace Science and Technology, Vol. 116, 2021.
  •  
  • [8] R. H. Sundararaj, T. C. Sekar, R. Arora, A. N. Rao and A. Kushari, "Performance simulation of an engine retrofitted with thrust vectoring capabilities," in Gas Turbine India Conference 2019, Vol. 83532, pp. V002T009A007.
  • [9] A. Gharbi, "Dynamic Simulation of a Turbofan Engine", M.S. thesis, Dept. Aerospace. Eng., Amirkabir Univ. of Technology, Tehran, Iran, 2008. (inPersian)
  • [10] S. Jafari panah, "Modeling And Functional characteristics Analysis of a Light Aircraft Engine (SATS)", M.S. thesis, Dept. of Aerospace. Eng., Tarbiat Modares Univ., Tehran, Iran, 2012. (inPersian)
  • [11] S. L. Dixon and  C. A. Hall, Fluid Mechanics and Thermodynamics of Turbomachinery,  7th ed.: Elsevier, 2014.
  • [12] S. Farokhi, Aircraft Propulsion, 2th ed.: Wiley, 2014.