High-speed unsteady flows around spiked-blunt bodies

Argyris G. Panaras, Dimitris Drikakis

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

This paper presents a detailed investigation of unsteady supersonic and hypersonic flows around spiked-blunt bodies, including the investigation of the effects of the flow field initialization on the flow results. Past experimental research has shown that if the geometry of a spiked-blunt body is such that a shock formation consisting of an oblique foreshock and a bow aftershock appears, then the flow may be unsteady. The unsteady flow is characterized by periodic radial inflation and collapse of the conical separation bubble formed around the spike (pulsation). Beyond a certain spike length the flow is ‘stable’, i.e. steady or mildly oscillating in the radial direction. Both unsteady and ‘stable’ conditions have been reported when increasing or decreasing the spike length during an experimental test and, additionally, hysteresis effects have been observed. The present study reveals that for certain geometries the numerically simulated flow depends strongly on the assumed initial flow field, including the occurrence of bifurcations due to inherent hysteresis effects and the appearance of unsteady flow modes. Computations using several different configurations reveal that the transient (initial) flow development corresponds to a nearly inviscid flow field characterized by a foreshock–aftershock interaction. When the flow is pulsating, the further flow development is not sensitive to initial conditions, whereas for an oscillating or almost ‘steady’ flow, the flow development depends strongly on the assumed initial flow field.
LanguageEnglish
Pages69-96
Number of pages28
JournalJournal of Fluid Mechanics
Volume632
DOIs
Publication statusPublished - 1 Aug 2009

Fingerprint

blunt bodies
unsteady flow
Unsteady flow
Flow fields
high speed
flow distribution
Hysteresis
spikes
Hypersonic flow
Geometry
Supersonic flow
Steady flow
hysteresis
inviscid flow
hypersonic flow
supersonic flow
steady flow
bows
geometry
bubbles

Keywords

  • unsteady supersonic flows
  • unsteady hypersonic flows
  • spiked-blunt bodies

Cite this

Panaras, Argyris G. ; Drikakis, Dimitris. / High-speed unsteady flows around spiked-blunt bodies. In: Journal of Fluid Mechanics. 2009 ; Vol. 632. pp. 69-96.
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High-speed unsteady flows around spiked-blunt bodies. / Panaras, Argyris G.; Drikakis, Dimitris.

In: Journal of Fluid Mechanics, Vol. 632, 01.08.2009, p. 69-96.

Research output: Contribution to journalArticle

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