An extensive investigation of velocity fluctuation spectra has been performed in the weakly compressible, decaying turbulent field established in the test section of a small scale hypersonic wind tunnel. The measured one-dimensional spectra exhibits a non-Kolmogorov power-law behavior over a significant wavenumber range, with a -11/3 exponent which is not predicted by available scaling relations for compressible turbulence. On the other hand, such power-law exponent is in agreement with recent EDQNM and LES results for the irrotational component of velocity fluctuations in weakly compressible flows. Based on these result, a new dimensionallybased scaling relation is obtained for the compressible energy spectrum, which is in agreement with the numerically observed radiative behavior for weakly compressible turbulence.
Measurements of Energy Spectra in Weakly Compressible Turbulence
D'AGOSTINO, LUCA
1999-01-01
Abstract
An extensive investigation of velocity fluctuation spectra has been performed in the weakly compressible, decaying turbulent field established in the test section of a small scale hypersonic wind tunnel. The measured one-dimensional spectra exhibits a non-Kolmogorov power-law behavior over a significant wavenumber range, with a -11/3 exponent which is not predicted by available scaling relations for compressible turbulence. On the other hand, such power-law exponent is in agreement with recent EDQNM and LES results for the irrotational component of velocity fluctuations in weakly compressible flows. Based on these result, a new dimensionallybased scaling relation is obtained for the compressible energy spectrum, which is in agreement with the numerically observed radiative behavior for weakly compressible turbulence.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
