Numerical investigation of the shock formation process in underexpanded jets

S. Li, B. Muddle, Mahnaz Jahedi, J. Soria

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearch


Supersonic jets can be found in a wide range of aeronautical applications. The general shock structures underlying both free and impinging underexpanded jets is well understood. The present numerical investigation is an attempt to characterise the shock formation process of underexpanded impinging and free jets. To do this, a moving planar shock is passed through a pipe into the ambient air. The resulting flow field exhibits the characteristics of either a highly or moderately underexpanded jet depending on the shock propagation speed. In the present study, a planar shock travelling at Ms =1.5 and 1.8 was used to reproduce the shock diamonds and Mach disks commonly associated with moderately and highly underexpanded jets respectively. The study revealed that the the inner, outer and tail shocks are formed near the pipe wall along with the production of a large convecting vortex rotating in the counter clockwise direction.

Original languageEnglish
Title of host publication14th Australian International Aerospace Congress, AIAC 2011
Subtitle of host publicationMelbourne, VIC, Australia; 28 February 2011 through 3 March 2011
Place of PublicationMelbourne, VIC, Australia
PublisherEngineers Australia
Number of pages10
ISBN (Print)9780987086303
Publication statusPublished - 2011
EventAustralian International Aerospace Congress 2011 - Melbourne Convention Centre, Melbourne, Australia
Duration: 28 Feb 20113 Mar 2011
Conference number: 14th


ConferenceAustralian International Aerospace Congress 2011
Abbreviated titleAIAC 2011
Internet address


  • Density and velocity
  • Jets
  • Pressure
  • Shocks
  • Supersonic
  • Underexpanded
  • Vortex

Cite this