Advances in aircraft and spacecraft science

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Enlarge duct length optimization for suddenly expanded flows

  • Pathan, Khizar A. (Department of Mechanical Engineering, Trinity College of Engineering and Research) ;
  • Dabeer, Prakash S. (Department of Mechanical Engineering, Acharya Institute of Technology) ;
  • Khan, Sher A. (Department of Mechanical Engineering, International Islamic University Malaysia)
  • Received : 2019.03.30
  • Accepted : 2019.11.19
  • Published : 2020.05.25
⟨ Previous Next ⟩

Abstract

In many applications like the aircraft or the rockets/missiles, the flow from a nozzle needs to be expanded suddenly in an enlarged duct of larger diameter. The enlarged duct is provided after the nozzle to maximize the thrust created by the flow from the nozzle. When the fluid is suddenly expanded in an enlarged duct, the base pressure is generally lower than the atmospheric pressure, which results in base drag. The objective of this research work is to optimize the length to diameter (L/D) ratio of the enlarged duct using the CFD analysis in the flow field from the supersonic nozzle. The flow from the nozzle drained in an enlarged duct, the thrust, and the base pressure are studied. The Mach numbers for the study were 1.5, 2.0 and 2.5. The nozzle pressure ratios (NPR) of the study were 2, 5 and 8. The L/D ratios of the study were 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. Based on the results, it is concluded that the L/D ratio should be increased to an optimum value to reattach the flow to an enlarged duct and to increase the thrust. The supersonic suddenly expanded flow field is wave dominant, and the results cannot be generalized. The optimized L/D ratios for various combinations of flow and geometrical parameters are given in the conclusion section.

Keywords

References

  1. Aabid, A., Khan, A., Mazlan, N.M., Ismail, M.A., Akhtar, M.N. and Khan, S.A. (2019), "Numerical simulation of suddenly expanded flow at Mach 2.2", Int. J. Eng. Adv. Technol., 8(3), 457-462.
  2. Allison, D.L., Morris, C.C., Schetz, J.A., Kapania, R.K., Watson, L.T. and Deaton, J.D. (2015), "Development of a multidisciplinary design optimization framework for an efficient supersonic air vehicle", Adv. Aircraft Spacecraft Sci., 2(1), 17-44. https://doi.org/10.12989/aas.2014.2.1.017.
  3. Asadullah, M., Khan, S.A., Asrar, W. and Sulaeman, E. (2018b), "Low-cost base drag reduction technique", Int. J. Mech. Eng. Robot. Res., 7(4), 428-432. https://doi.org/10.18178/ijmerr.7.4.428-432
  4. Asadullah, M., Khan, S.A., Asrar, W. and Sulaeman, E. (2018a), "Counter-clockwise rotation of cylinder with variable position to control base flows", Proceedings of the International Conference on Aerospace and Mechanical Engineering (AeroMech17), Penang, Malaysia, November.
  5. Candon, M.J., Ogawa, H. and Dorrington, G.E. (2015), "Thrust augmentation through after-burning in scramjet nozzles", Adv. Aircraft Spacecraft Sci., 2(2), 183-198. https://doi.org/10.12989/aas.2015.2.2.183.
  6. Hoerner, S.F. (1949), "Base drag and thick trailing edges", J. Aeronaut. Sci., 17(10), 622-628. https://doi.org/10.2514/8.1750.
  7. Khan, A., Aabid, A. and Khan, S.A. (2018), "CFD analysis of convergentdivergent nozzle flow and base pressure control using micro-JETS", Int. J. Eng. Technol., 7(3.29), 232-235. https://doi.org/10.14419/ijet.v7i3.29.18802.
  8. Khan, S.A., Fatepurwala, M.A. and Pathan, K.N. (2018), "CFD analysis of human powered submarine to minimize drag", Int. J. Mech. Prod. Eng. Res. Dev., 8(3), 1057-1066. https://doi.org/10.24247/ijmperdjun2018111.
  9. Kuzmin, A. (2019), "Shock wave instability in a bent channel with subsonic/supersonic exit", Adv. Aircraft Spacecraft Sci., 6(1), 19-30. https://doi.org/10.12989/aas.2019.6.1.019
  10. Kuzmin, A. and Babarykin, K. (2018), "Supersonic flow bifurcation in twin intake models", Adv. Aircraft Spacecraft Sci., 5(4), 445-458. https://doi.org/10.12989/aas.2018.5.4.445.
  11. Mehta, R.C. and Natarajan, G. (2014), "Numerical simulations of convergent-divergent nozzle and straight cylindrical supersonic diffuser", Adv. Aircraft Spacecraft Sci., 1(4), 399-408. https://doi.org/10.12989/aas.2014.1.4.399.
  12. Pathan, K.A., Dabeer, P.S. and Khan, S.A. (2018a), "Optimization of area ratio and thrust in suddenly expanded flow at supersonic Mach numbers", Case Stud. Therm. Eng., 12, 696-700. https://doi.org/10.1016/j.csite.2018.09.006.
  13. Pathan, K.A., Dabeer, P.S. and Khan, S.A. (2019a), "Investigation of base pressure variations in internal and external suddenly expanded flows using CFD analysis", CFD Lett., 11(4), 32-40.
  14. Pathan, K.A., Dabeer, P.S. and Khan, S.A. (2019b), "Effect of nozzle pressure ratio and control jets location to control base pressure in suddenly expanded flows", J. Appl. Fluid Mech., 12(4), 1127-1135. https://doi.org/10.29252/jafm.12.04.29495.
  15. Pathan, K.A., Dabeer, P.S. and Khan, S.A. (2019c), "Influence of expansion level on base pressure and reattachment length", CFD Lett., 11(5), 22-36.
  16. Pathan, K.A., Dabeer, P.S. and Khan, S.A. (2019d), "An investigation of effect of control jets location and blowing pressure ratio to control base pressure in suddenly expanded flows", J. Therm. Eng.
  17. Pathan, K.A., Dabeer, P.S. and Khan, S.A. (2018b), "An investigation to control base pressure in suddenly expanded flows", Int. Rev. Aerosp. Eng., 11(4), 162-169. https://doi.org/10.15866/irease.v11i4.14675.
  18. Pathan, K.A., Khan, S.A. and Dabeer, P.S. (2017a), "CFD analysis of the effect of Mach number, area ratio, and nozzle pressure ratio on velocity for suddenly expanded flows", Proceedings of the 2nd International Conference for Convergence in Technology (I2CT), Pune, India, April.
  19. Pathan, K.A., Khan, S.A. and Dabeer, P.S. (2017b), "CFD analysis of the effect of area ratio on suddenly expanded flows", Proceedings of the 2nd International Conference for Convergence in Technology (I2CT), Pune, India, April.
  20. Pathan, K.A., Khan, S.A. and Dabeer, P.S. (2017c), "CFD analysis of the effect of flow and geometry parameters on thrust force created by flow from nozzle", Proceedings of the 2nd International Conference for Convergence in Technology (I2CT), Pune, India, April.