Shock Interactions in Thrust Optimised Parabolic (TOP) Nozzles during Start-Up and Shutdown

  • Ijaz Mohamed
  • G. RajeshEmail author
Conference paper


The separation phenomenon in parabolic nozzles has long been studied in detail and is well documented. The parabolic nozzles are normally being operated in those regimes of pressure ratios where separation does not occur. However, during the start-up and shutdown transience, the operation of the nozzles inherently falls in the separation regimes due to the lower total pressures they experience. The present work is an attempt to study the shock structures in a thrust optimised parabolic (TOP) which occur during the separation process in nozzle and its interaction due to which either a free shock separation (FSS) or restricted shock separation is observed (RSS). The hysteresis of FSS↔RSS transition during the start-up and shutdown transiency is also studied. A complete transient analysis on shock structure interactions in 2D axisymmetric TOP nozzle of area ratio 36 was carried out, and the results were used to interpret the shock interactions, separation patterns and hysteresis effects.


  1. 1.
    L.H. Nave, G.A. Coffey, “Sea level side loads in high-area-ratio rocket engines, in AIAA Paper 73-1284, AIAA/SAE 9th Propulsion Conference, Las Vegas, Neveda, 1973Google Scholar
  2. 2.
    C.L. Chen, S.R. Chakravarthy, C.M. Hung, Numerical investigation of separated nozzle flows. AIAA J. 32, 1836–1843 (1994)CrossRefGoogle Scholar
  3. 3.
    F. Nasuti, M. Onofri, Viscous and Inviscid Vortex generation during Nozzle flow transients, AIAA 96-0076, June 1996Google Scholar
  4. 4.
    M. Frey, G. Hagemann, Status of flow separation prediction in Rocket Nozzles, AIAA 98-3619, 1998Google Scholar
  5. 5.
    M. Frey, G. Hagemann, Flow separation and side-loads in Rocket Nozzles, AIAA 99-2815, 1999Google Scholar
  6. 6.
    J. Östlund, Flow processes in Rocket Engine Nozzles with focus on flow separation and side-loads, Technical reports, Royal Institute of Technology Department of Mechanics, S-100 44 Stockholm, Sweden. (2002)Google Scholar
  7. 7.
    J. Östlund, T. Damgaard, M. Frey, Side-load phenomena in highly overexpanded Rocket Nozzles, AIAA-2001-3684Google Scholar
  8. 8.
    S.B Verma, Flow separation characteristics of a thrust optimized parabolic Nozzle in a high altitude simulation chamber, AIAA 2012-6658, 2012Google Scholar
  9. 9.
    F. Nasuti, M. Onofri, Shock structure in separated nozzle flows. Shock Waves 19, 229–237 (2009)CrossRefGoogle Scholar
  10. 10.
    E. Martelli, F. Nasuti, M. Onofri, Numerical calculation of FSS/RSS transition in highly overexpanded rocket nozzle flows. Shock Waves 20, 139–146 (2010)CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Aerospace EngineeringIndian Institute of Technology MadrasChennaiIndia

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