• DOI:10.1063/1.1355682
• Corpus ID: 13893338

Direct numerical simulation of decaying compressible turbulence and shocklet statistics

@article{Samtaney2001DirectNS,
  title={Direct numerical simulation of decaying compressible turbulence and shocklet statistics},
  author={Ravi Samtaney and D. I. Pullin and Branko Kosovi{\'c}},
  journal={Physics of Fluids},
  year={2001},
  volume={13},
  pages={1415-1430}
}

• R. Samtaney, D. Pullin, B. Kosović
• Published 12 April 2001
• Physics
• Physics of Fluids

We present results from 1283 and 2563 direct numerical simulations (DNS) of decaying compressible, isotropic turbulence at fluctuation Mach numbers of Mt∼0.1–0.5 and at Taylor Reynolds numbers Reλ=O(50–100). The presence or absence of fluctuations of thermodynamic quantities as well as velocity divergence in the initial conditions are found to have a negligible effect on the decay of turbulent kinetic energy. The decay of the turbulent kinetic energy shows no significant effect of Mt and power laws fitted to the timewise decay exhibit exponents n=1.3–1.7 that are similar to those found for decaying incompressible turbulence. The main new phenomenon produced by compressibility is the appearance of random shocklets which form during the main part of the decay. An algorithm is developed to extract and quantify the shocklet statistics from the DNS fields. A model for the probability density function (PDF) of the shocklet strength Mn−1 (Mn is the normal shock Mach number) is derived based on combining weak-sho...