A PROPOSITION TO DETERMINE WINDOW AVERAGE FOR TURBULENT FLOWS BY MULTIRESOLUTION DECOMPOSITION

Authors

  • Franco Cassol Grupo de Modelagem Atmosférica de Santa Maria
  • Franciano Scremin Puhales Grupo de Modelagem Atmosférica de Santa Maria
  • Otávio Costa Acevedo Universidade Federal de Santa Maria
  • Gervásio Annes Degrazia Universidade Federal de Santa Maria
  • Vagner Anabor Grupo de modelagem atmosférica de Santa Maria
  • Everson Dal Piva Grupo de modelagem atmosférica de Santa Maria
  • Felipe Denardin Costa Universidade Federal do Pampa

DOI:

https://doi.org/10.5902/2179460X19956

Keywords:

Stable boundary layer. Reynolds average. Spectral gap. Multiresolution spectrum.

Abstract

The estimative of turbulent quantities by Reynolds average depend on time scale average. This average window should be great enough to describe all turbulent contributions and small enough to filter the largest scales (low frequencies contributions). In this work are applied the multiresolution decomposition to find the spectral gap that split the turbulent of non-turbulent motions, this way the best time scale for the Reynolds average. The results of that methodology are compared with 1, 5, 15, and 30min windows average. This task is accomplished by the linear correlation between tubulent kinetic energy and friction velocity scale. The results reveal a better linear relationship between kinetic energy and friction velocity scale with adaptative time scale average than ones found with frozen window average.

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References

Acevedo, O. C., Costa, F. D., Oliveira, P. E., Puhales, F. S., Degrazia, G. A., Roberti, D.R. (2014). The influence of submeso processes on stable boundary layer similarity relationships. Journal of the Atmospheric Sciences, 71(1), 207–225.

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Wyngaard, J. C. (2010). Turbulence in the atmosphere. Cambridge University Press, Cambridge.

Published

2016-07-20

How to Cite

Cassol, F., Puhales, F. S., Acevedo, O. C., Degrazia, G. A., Anabor, V., Piva, E. D., & Costa, F. D. (2016). A PROPOSITION TO DETERMINE WINDOW AVERAGE FOR TURBULENT FLOWS BY MULTIRESOLUTION DECOMPOSITION. Ciência E Natura, 38, 61–65. https://doi.org/10.5902/2179460X19956

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