Rayleigh–Taylor and Richtmyer–Meshkov instability induced flow, turbulence, and mixing. II

Zhou, Ye

doi:10.1016/j.physrep.2017.07.008

Cited by 457 publications

(254 citation statements)

References 1,022 publications

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“…However, as the perturbation amplitudes become large with respect to the wavelength, the layer growth enters the nonlinear regime, whereby numerical simulation is required to calculate the subsequent evolution. For a comprehensive and up-to-date review of the literature on RMI, the reader is referred to Zhou [3,4].…”

Section: Introductionmentioning

confidence: 99%

The influence of initial perturbation power spectra on the growth of a turbulent mixing layer induced by Richtmyer–Meshkov instability

Groom

Thornber

2020

Physica D: Nonlinear Phenomena

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This paper investigates the influence of different broadband perturbations on the evolution of a Richtmyer-Meshkov turbulent mixing layer initiated by a Mach 1.84 shock traversing a perturbed interface separating gases with a density ratio of 3:1. Both the bandwidth of modes in the interface perturbation, as well as their relative amplitudes, are varied in a series of carefully designed numerical simulations at grid resolutions up to 3.2×10 9 cells. Three different perturbations are considered, characterised by a power spectrum of the form P (k) ∝ k m where m = −1, −2 and −3. The growth of the mixing layer is shown to strongly depend on the initial conditions, with the growth rate exponent θ found to be 0.5, 0.63 and 0.75 for each value of m at the highest grid resolution. The asymptotic values of the molecular mixing fraction Θ are also shown to vary significantly with m; at the latest time considered Θ is 0.56, 0.39 and 0.20 respectively. Turbulent kinetic energy (TKE) is also analysed in both the temporal and spectral domains. The temporal decay rate of TKE is found not to match the predicted value of n = 2 − 3θ, which is shown to be due to a time-varying normalised dissipation rate C . In spectral space, the data follow the theoretical scaling of k (m+2)/2 at low wavenumbers and tend towards k −3/2 and k −5/3 scalings at high wavenumbers for the spectra of transverse and normal velocity components respectively. The results represent a significant extension of previous work on the Richtmyer-Meshkov instability evolving from broadband initial perturbations and provide useful benchmarks for future research.

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Section: Introductionmentioning

confidence: 99%

The influence of initial perturbation power spectra on the growth of a turbulent mixing layer induced by Richtmyer–Meshkov instability

Groom

Thornber

2020

Physica D: Nonlinear Phenomena

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“…For example, in combustion applications, the initial amounts of pure fluids can vary significantly from fuel rich to lean conditions.. Different initial amounts of heavy and light fluids also pose a new challenge for mix models, and have not been tested before [20,21]. We thus choose to alter the initial composition ratio to identify possible effects of differential initial density distributions in HVDT mixing with the low (1.1 : 1) and high (7 : 1) density ratios.…”

Section: Introductionmentioning

confidence: 99%

Variable-density buoyancy-driven turbulence with asymmetric initial density distribution

Aslangil

Livescu

Banerjee

2020

Physica D: Nonlinear Phenomena

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The effects of different initial density distributions on the evolution of buoyancy-driven homogeneous variable-density turbulence (HVDT) at low (0.05) and high (0.75) Atwood numbers are studied by using high-resolution direct numerical simulations. HVDT aims to mimic the acceleration-driven Rayleigh-Taylor and shock-driven Richtmyer-Meshkov instabilities and reveals new physics that arise from variable-density effects on the turbulent mixing. Here, the initial amounts of pure light and pure heavy flows are altered primarily to mimic the variable-density turbulence at the different locations of the Rayleigh-Taylor and Richtmyer-Meshkov instabilities' mixing layers where the amounts of the mixing fluids are not equal. It is found that for the low Atwood number cases, the asymmetric initial density distribution has limited effects on both global and local flow evolution for HVDT. However, at high Atwood number, both global flow evolution and the local flow structures are strongly affected by the initial composition ratio. The flow composed of more light fluid reaches higher turbulent levels and the local statistics reach their fully-developed behavior earlier in the time evolution. During the late time decay, where most of the flow is well-mixed, all parameters become independent of the initial composition ratio for both low and high Atwood number cases.

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“…[76,77]. While, in previous studies, nearly all numerical investigations were based on hydrodynamic equations at the Euler level [8,10,18,25,26,[33][34][35][36][37]48] which assume that the system is always in its local thermodynamic equilibrium.…”

Section: Introductionmentioning

confidence: 99%

Nonequilibrium and morphological characterizations of Kelvin–Helmholtz instability in compressible flows

Gan

Zhang

et al. 2019

Front. Phys.

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We investigate the effects of viscosity and heat conduction on the onset and growth of Kelvin-Helmholtz instability (KHI) via an efficient discrete Boltzmann model. Technically, two effective approaches are presented to quantitatively analyze and understand the configurations and kinetic processes. One is to determine the thickness of mixing layers through tracking the distributions and evolutions of the thermodynamic nonequilibrium (TNE) measures; the other is to evaluate the growth rate of KHI from the slopes of morphological functionals. Physically, it is found that the time histories of width of mixing layer, TNE intensity, and boundary length show high correlation and attain their maxima simultaneously. The viscosity effects are twofold, stabilize the KHI, and enhance both the local and global TNE intensities. Contrary to the monotonically inhibiting effects of viscosity, the heat conduction effects firstly refrain then enhance the evolution afterwards. The physical reasons are analyzed and presented.

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Rayleigh–Taylor and Richtmyer–Meshkov instability induced flow, turbulence, and mixing. II

Cited by 457 publications

References 1,022 publications

The influence of initial perturbation power spectra on the growth of a turbulent mixing layer induced by Richtmyer–Meshkov instability

The influence of initial perturbation power spectra on the growth of a turbulent mixing layer induced by Richtmyer–Meshkov instability

Variable-density buoyancy-driven turbulence with asymmetric initial density distribution

Nonequilibrium and morphological characterizations of Kelvin–Helmholtz instability in compressible flows

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