TY - JOUR
T1 - The influence of initial conditions on turbulent mixing due to Richtmyer-Meshkov instability
AU - Thornber, B.
AU - Drikakis, D.
AU - Youngs, D. L.
AU - Williams, R. J.R.
PY - 2010/7/1
Y1 - 2010/7/1
N2 - This paper investigates the influence of different three-dimensional multi-mode initial conditions on the rate of growth of a mixing layer initiated via a Richtmyer-Meshkov instability through a series of well-controlled numerical experiments. Results are presented for large-eddy simulation of narrowband and broadband perturbations at grid resolutions up to 3 10 9 points using two completely different numerical methods, and comparisons are made with theory and experiment. It is shown that the mixing-layer growth is strongly dependent on initial conditions, the narrowband case giving a power-law exponent θ≈0.26 at low Atwood and θ≈0.3 at high Atwood numbers. The broadband case uses a perturbation power spectrum of the form P(k) k2 with a proposed theoretical growth rate of θ= 2/3. The numerical results confirm this; however, they highlight the necessity of a very fine grid to capture an appropriately broad range of initial scales. In addition, an analysis of the kinetic energy decay rates, fluctuating kinetic energy spectra, plane-averaged volume fraction profiles and mixing parameters is presented for each case.
AB - This paper investigates the influence of different three-dimensional multi-mode initial conditions on the rate of growth of a mixing layer initiated via a Richtmyer-Meshkov instability through a series of well-controlled numerical experiments. Results are presented for large-eddy simulation of narrowband and broadband perturbations at grid resolutions up to 3 10 9 points using two completely different numerical methods, and comparisons are made with theory and experiment. It is shown that the mixing-layer growth is strongly dependent on initial conditions, the narrowband case giving a power-law exponent θ≈0.26 at low Atwood and θ≈0.3 at high Atwood numbers. The broadband case uses a perturbation power spectrum of the form P(k) k2 with a proposed theoretical growth rate of θ= 2/3. The numerical results confirm this; however, they highlight the necessity of a very fine grid to capture an appropriately broad range of initial scales. In addition, an analysis of the kinetic energy decay rates, fluctuating kinetic energy spectra, plane-averaged volume fraction profiles and mixing parameters is presented for each case.
UR - http://www.scopus.com/inward/record.url?scp=77957151979&partnerID=8YFLogxK
U2 - 10.1017/S0022112010000492
DO - 10.1017/S0022112010000492
M3 - Article
AN - SCOPUS:77957151979
SN - 0022-1120
VL - 654
SP - 99
EP - 139
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
ER -