摘要
Scaling laws are addressed by analysing moments of velocity increments which obtained by Particle-image Velocimetry(PIV)system in the boundary layer of a flat plate.In the paper,we measure the moments of increments of upstream velocity(u'),longitudinal velocity(v')and ponderance of vorticity(dv'/dx)at Reθ=2167 in different wall distance and verify the anomaly of the scaling exponents of high-order structure functions with the increasing order of the moments,discuss the scaling of non-integer moments of order between+2 and-1.The difference of scaling exponents of low-order structure functions between the experimental data and Kolmogorov's,SL's(She & Leveque)prediction increases as the moment order decreases toward-1,which shows that the anomaly is manifested in low-oeder moments as well.However,for same order structure functions,the scaling exponents of v' and dv'/dx are not changeable in different wall distance.
Scaling laws are addressed by analysing moments of velocity increments which obtained by Particleimage Velocimetry （PIV） system in the boundary layer of a flat plate. In the paper, we measure the moments of increments of upstream velocity （u＇）, longitudinal velocity （v＇） and ponderance of vorticity （dv＇/dx） at Reo = 2167 in different wall distance and verify the anomaly of the scaling exponents of hlgh-order structure functions with the increasing order of the moments, discuss the scaling of non-integer moments of order between ＋ 2 and - 1. The difference of scaling exponents of low-order structure functions between the experimental data and Kolmogorov＇ s, SL＇s （She ＆ Leveque） prediction increases as the moment order decreases toward -l, which shows that the anomaly is manifested in low-oeder moments as well. However, for same order structure functions, the sealing exponents of v＇ and dv＇/dx are not changeable in different wall distance.
基金
Sponsored by the National Natural Science Foundation of China(Grant No.10372033)
