Asymmetric and Unsteady Flow Separation in High Mach Number Planar Nozzles

E Shimshi, G Ben-Dor, A Krothapalli, Abraham Levy

Research output: Contribution to journalArticlepeer-review


This paper presents numerical and experimental findings regarding flow separation phenomenon in a high Mach number over expanded planar nozzle. The experimental work is done using a tapered nozzle with a variable area ratio that can produce separation Mach numbers in the range 2.6-3.5. Shadowgraph visualization reveals that depending on the nozzle pressure ratio and the area ratio, steady symmetric, unsteady symmetric and steady asymmetric separations can occur. These separation types are reproduced by numerical simulations. The unsteady separation produces a sharp tone, which does not match the characteristics of familiar tone producing mechanisms. The transition to asymmetric separation results in attachment of the jet to the nozzle wall, and the reverse transition is accompanied by a hysteresis effect.
Original languageEnglish
Pages (from-to)65-80
Number of pages15
JournalInternational Journal of Aeronautical Science & Aerospace Research
Issue number6
StatePublished - Dec 2015


Dive into the research topics of 'Asymmetric and Unsteady Flow Separation in High Mach Number Planar Nozzles'. Together they form a unique fingerprint.

Cite this