Computing multi-mode shock-induced compressible turbulent mixing at late times

T. Oggian, D. Drikakis, D. L. Youngs, R. J. R. Williams

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Both experiments and numerical simulations pertinent to the study of self-similarity in shock-induced turbulent mixing often do not cover sufficiently long times for the mixing layer to become developed in a fully turbulent manner. When the Mach number of the flow is sufficiently low, numerical simulations based on the compressible flow equations tend to become less accurate due to inherent numerical cancellation errors. This paper concerns a numerical study of the late-time behaviour of a single-shocked Richtmyer–Meshkov instability (RMI) and the associated compressible turbulent mixing using a new technique that addresses the above limitation. The present approach exploits the fact that the RMI is a compressible flow during the early stages of the simulation and incompressible at late times. Therefore, depending on the compressibility of the flow field, the most suitable model, compressible or incompressible, can be employed. This motivates the development of a hybrid compressible–incompressible solver that removes the low-Mach-number limitations of the compressible solvers, thus allowing numerical simulations of late-time mixing. Simulations have been performed for a multi-mode perturbation at the interface between two fluids of densities corresponding to an Atwood number of 0.5, and results are presented for the development of the instability, mixing parameters and turbulent kinetic energy spectra. The results are discussed in comparison with previous compressible simulations, theory and experiments.
LanguageEnglish
Pages411-431
Number of pages21
JournalJournal of Fluid Mechanics
Volume779
Early online date19 Aug 2015
DOIs
Publication statusPublished - 1 Sep 2015

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turbulent mixing
shock
Compressible flow
compressible flow
simulation
Mach number
Computer simulation
Compressibility
flow equations
Kinetic energy
Flow fields
cancellation
compressibility
Experiments
flow distribution
energy spectra
kinetic energy
Fluids
perturbation
fluids

Keywords

  • shock waves
  • turbulence simulation
  • turbulent mixing

Cite this

Oggian, T. ; Drikakis, D. ; Youngs, D. L. ; Williams, R. J. R. / Computing multi-mode shock-induced compressible turbulent mixing at late times. In: Journal of Fluid Mechanics. 2015 ; Vol. 779. pp. 411-431.
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Computing multi-mode shock-induced compressible turbulent mixing at late times. / Oggian, T.; Drikakis, D.; Youngs, D. L.; Williams, R. J. R.

In: Journal of Fluid Mechanics, Vol. 779, 01.09.2015, p. 411-431.

Research output: Contribution to journalArticle

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AU - Drikakis, D.

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