Experimental analysis of the scaling law and the flow structure in turbulent boundary layer
K Zhang · Yunnan Daxue xuebao. Shehui kexue ban · 2015
As a universal principle of turbulence cascade,scaling law is important in the research on statistics of turbulence. In the thesis PIV system has been used to measure the fluctuating velocity in order to analyze the parameters( the intermittence factor and the exponent of the most intermittent structure) of SL scaling law in boundary layer at Reθ= 2 694. The method of wavelet and statistics have been used in this paper. At different distances from the wall and different scale,the results show the intermittence factor is changeable. However,with rising the distance from wall and scale,the exponent of the most intermittent structure tends to be stable. When the scale is big enough,the exponent of the most intermittent structure doesn't relate to the distances from the wall.The original graph and the picture of wavelet reconstruction demonstrate the process of turbulent cascade and correctness of the scaling law.