The effect of Reynolds number on the scaling range along the centreline of a round turbulent jet

作者：Sadeghi Hamed; Lavoie Philippe; Pollard Andrew^*

来源：Journal of Turbulence, 2014, 15(6): 335-349.

DOI：10.1080/14685248.2014.906810

• Reynolds number
• structure functions
• energy spectra
• turbulent jet
• scaling range

In this paper, the effect of Reynolds number on the scaling range of the velocity spectra and structure functions along the centreline in a round turbulent jet is considered. Hot-wire measurements were taken over a range of exit Reynolds numbers (). Both axial (u) and transverse (v) energy spectra in the scaling range demonstrate considerable departure from the k(-5/3) (Kolmogorov inertial range scaling). Over the present range of Reynolds numbers, the scaling wave number exponent for axial, m(1), and transverse, m(2), spectra exhibit monotonic changes with Taylor Reynolds number: , . On the jet centreline, the data are in close agreement with the earlier findings for grid-generated turbulence. In addition, the structure functions are investigated. The scaling exponent for the second-order structure functions increases with in a power-law fashion () similar to the spectra. The peak value of the normalised third-order structure function C-3 asymptotically approaches 4/5 as the Reynolds numbers increases: . The present round jet data confirm that a proper inertial range is unlikely to be established along the jet axis unless a very high Reynolds number of can be reached.

• 出版日期2014-6-3