Vol. 2 (2026)

Articles

Numerical Simulation and Visualization of Plug Truncation Effects on Supersonic Turbulent Flow in a Conical Aerospike Nozzle

Published 2026-10-07

  • O. Anwar Bég
    • ,
  • C. Okuzu
    • ,
  • Tasveer A. Bég
    • ,
  • M.M. Bhatti
    • ,
  • S. Kuharat
    • ,
  • Henry J. Leonard
    • ,
  • Ali Kadir
    • ,
  • W.S. Jouri

O. Anwar Bég
Multi-Physical Engineering Sciences Group, Mechanical Engineering Department, Corrosion and Coatings Lab, Room 3-08, SEE Building, University of Salford, Manchester, M54WT, UK

C. Okuzu
Formerly, Aeronautical Engineering Programme, SEE Building, Salford University, Manchester, M54WT, UK

Tasveer A. Bég
Engineering Mechanics Research, Israfil House, Dickenson Rd., Manchester, M13, UK

M.M. Bhatti
"Department of Physics, College of Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea" & "Material Science Innovation and Modelling (MaSIM) Research Focus Area, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa"

S. Kuharat
Multi-Physical Engineering Sciences Group, Mechanical Engineering Department, Corrosion and Coatings Lab, Room 3-08, SEE Building, University of Salford, Manchester, M54WT, UK

Henry J. Leonard
Multi-Physical Engineering Sciences Group, Mechanical Engineering Department, Corrosion and Coatings Lab, Room 3-08, SEE Building, University of Salford, Manchester, M54WT, UK

Ali Kadir
Multi-Physical Engineering Sciences Group, Mechanical Engineering Department, Corrosion and Coatings Lab, Room 3-08, SEE Building, University of Salford, Manchester, M54WT, UK

W.S. Jouri
Multi-Physical Engineering Sciences Group, Mechanical Engineering Department, Corrosion and Coatings Lab, Room 3-08, SEE Building, University of Salford, Manchester, M54WT, UK

Abstract

Truncation of aerospike plug nozzles in high-speed propulsion has become widely adopted to reduce structural length and cooling demands. However, it introduces a low-pressure base region and wake losses which can offset performance gains. To explore possible improvements to this mode of propulsion, we present a numerical assessment of truncated conical aerospike nozzles at four plug-length ratios (40%, 50%, 62.5% and 75%) operating at nozzle pressure ratios and . Two-dimensional axisymmetric Reynolds-averaged Navier–Stokes turbulent gas dynamic simulations were performed for supersonic gas dynamics in ANSYS Fluent using a density-based solver with the SST turbulence model. Grid independence was established prior to the parametric study. Flow characteristics were quantified i.e. Mach number contours, static pressure fields, base pressure recovery trends, and net axial thrust/thrust coefficient comparisons. Results show that base pressure recovery increases with plug length; however, thrust does not improve monotonically with truncation ratio. Across both NPR conditions, the 50% truncated configuration delivered the highest net axial thrust (4556.82 N at ; 5204.34 N at ), indicating an optimum compromise between wake/base losses and expansion effectiveness. A simple idealised thrust estimate was used as a consistency check; as expected, CFD predicts lower effective performance due to base/wake losses and viscous/shock effects. The novelties of the present study include a generalization of the plug-length ratios (40%, 50%, 62.5% and 75%), operating at nozzle pressure ratios and , inclusion of a sophisticated turbulence model, and the extensive visualization of multiple scenarios to capture key gas dynamic characteristics, which provide a detailed insight into modern supersonic aerospace propulsion.

Keywords

Aerospike rocket nozzle gas dynamics, Mach contours, Nozzle pressure ratio (NPR), SST k"-" ω turbulence model, Base pressure recovery, ANSYS FLUENT, Wake losses

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References

  1. Flinn ED. Aerospike engine powers RLV savings. Aerospace America. 1996 Nov;34(11):18-19.
  2. Letchworth G. X-33 Reusable launch vehicle demonstrator, spaceport and range. In: AIAA Space 2011 Conference and Exposition; 2011 Sep 27-29; Long Beach, CA, USA. AIAA 2011-7314; 2011.
  3. Verma SB. Performance characteristics of an annular conical aerospike nozzle with freestream effect. AIAA J Propulsion and Power. 2009;25(3):783-791.
  4. Korte JJ, Trexler CA, Spaid FW. Investigation of altitude compensation for aerospike nozzles. Hampton, VA: NASA Langley; 1997 Feb. NASA Technical Memorandum 19970014941.
  5. Hagemann G, Immich H, Terhardt M. Flow phenomena in advanced rocket nozzles - The plug nozzle. In: 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit; 1998 Jul 13-15; Cleveland, USA. AIAA Paper 98-3522; 1998.
  6. Nair PP, Suryan A, Kim HD. Computational study on flow through truncated conical plug nozzle with base bleed. Propulsion and Power Research. 2019;8(2):108-120.
  7. Sullivan G. CFD and heat transfer analysis of rocket cooling techniques on an aerospike nozzle [MSc thesis]. Statesboro, GA: Georgia Southern University; 2022.
  8. Verma SB, Stark R, Haidn O. Relation between shock unsteadiness and the origin of side-loads in a thrust optimized parabolic rocket nozzle. Aerospace Science and Technology. 2006;10(6):474-483.
  9. Dutton JC, Carroll BF. A review of shock wave/boundary-layer interactions in high-speed flows. Progress in Aerospace Sciences. 1989;26(5):413-485.
  10. ANSYS FLUENT Theory Manual. Version 25. New Hampshire, USA: ANSYS Inc.; 2025.
  11. Daud HA, Li Q, Bég OA, Ghani SAA. Numerical investigations of wall-bounded turbulence. Proc Institution of Mechanical Engineers - Part C: Journal of Mechanical Engineering Science. 2011;225:1163-1174.
  12. Bég OA, Kuharat S, Bég TA, Pattison J, Kadir A, Jouri WS. Two-way fluid-structure interaction hydroelastic simulation of vibrating membranes with applications in marine renewable wave power. In: Soni A, Tripathi D, Sahariya J, Sharma KN, editors. Eco-Materials and Green Energy for a Sustainable Future. USA: CRC Press; 2024. p. 295-329.
  13. Menter FR. Two-equation eddy-viscosity turbulence models for engineering applications. AIAA Journal. 1994;32(8):1598-1605.
  14. Versteeg HK, Malalasekera W. An Introduction to Computational Fluid Dynamics: The Finite Volume Method. 2nd ed. Harlow, England: Pearson; 2007.
  15. Miller A, Bég OA, Bég TA, Bhatti MM, Kuharat S, Kadir A. Computational fluid dynamics simulation of rotor blade aerodynamics for the Mars ingenuity helicopter. J Computational Applied Mechanics. 2026;57(2):296-325.
  16. Angelino G. Approximate method for plug nozzle design. AIAA Journal. 1964;2(10):1834-1835.
  17. Rao GVR. Exhaust nozzle contour for optimum thrust. Jet Propulsion. 1958;28(6):377-382.
  18. Gorle S, Chaganti SS, Mandapudi S, Gudikandula S, Dussa G. Three-dimensional computational flow simulation of truncated aerospike nozzle considering different plug lengths. Indian Journal of Science and Technology. 2017;10(13).
  19. Escher WJD, Kaye TG. XRS-2200 linear aerospike rocket engine. Journal of Propulsion and Power. 2000;16(4):620-625.
  20. Merryman EL, et al. Supersonic drag reduction via base bleed technique. Journal of Propulsion and Power. 2005;21(2):240-247.
  21. Kadir A, Bég OA, El Gendy ME, Bég TA, Shamshuddin M. Computational fluid dynamic and thermal stress analysis of coatings for high-temperature corrosion protection of aerospace gas turbine blades. Heat Transfer. 2019;48(6):2302-2328.
  22. Chen H, Sun M, Xiong D, Yang Y, Wang T, Wang H. Large eddy simulation of supersonic flow in ducts with complex cross-sections. Theoretical and Applied Mechanics Letters. 2023;13(6):100469.
  23. Smirnov R, Shi S, Celik I. Random flow generation technique for Large Eddy Simulations (LES) and particle-dynamics modelling. ASME Journal of Fluids Engineering. 2001;123:359-371.
  24. Waqas M. Diffusion of stratification based chemically reactive Jeffrey liquid featuring mixed convection. Surfaces and Interfaces. 2021;23:100783.
  25. Waqas M. Analysis of thermally radiative magnetized viscoelastic (second grade) fluid by impermeable vertical cylinder. Waves in Random and Complex Media. 2026;35(7):12952-12966. DOI: 10.1080/17455030.2022.2139006.