Power law of decaying homogeneous isotropic turbulence at low Reynolds number
DSpace at IIT Bombay
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Title |
Power law of decaying homogeneous isotropic turbulence at low Reynolds number
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Creator |
BURATTINI, P
LAVOIE, P AGRAWAL, A DJENIDI, L ANTONIA, RA |
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Subject |
grid-generated turbulence
lattice boltzmann method direct numerical simulations energy-dissipation rate boundary-conditions passive scalar velocity-field statistics similarity pressure |
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Description |
We focus on an estimate of the decay exponent (m) in the initial period of decay of homogeneous isotropic turbulence at low Taylor microscale Reynolds number R-lambda (similar or equal to 20-50). Lattice Boltzmann simulations in a periodic box of 256(3) points are performed and compared with measurements in grid turbulence at similar R-lambda. Good agreement is found between measured and calculated energy spectra. The exponent m is estimated in three different ways: from the decay of the turbulent kinetic energy, the decay of the mean energy dissipation rate, and the rate of growth of the Taylor microscale. Although all estimates are close, as prescribed by theory, that from the Taylor microscale has the largest variability. It is then suggested that the virtual origin for the decay rate be determined from the Taylor microscale, but the actual value of m be estimated from the decay rate of the kinetic energy. The dependence of m on R-lambda(0) (the value of R-lambda at the beginning of the simulation) is also analyzed, using the present data as well as data from the literature. The results confirmed that m approaches 1, as R-lambda(0) increases.
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Publisher |
AMERICAN PHYSICAL SOC
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Date |
2011-07-17T18:25:13Z
2011-12-26T12:50:26Z 2011-12-27T05:35:06Z 2011-07-17T18:25:13Z 2011-12-26T12:50:26Z 2011-12-27T05:35:06Z 2006 |
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Type |
Article
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Identifier |
PHYSICAL REVIEW E, 73(6), -
1539-3755 http://dx.doi.org/10.1103/PhysRevE.73.066304 http://dspace.library.iitb.ac.in/xmlui/handle/10054/4805 http://hdl.handle.net/10054/4805 |
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Language |
en
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