INTERMITTENCY AND REYNOLDS-NUMBER

Hot wire measurements of longitudinal and transverse increments are pe rformed in three different types of flows on a large range of Reynolds numbers (100 less than or equal to R lambda less than or equal to 300 0). An improved technique based on cumulant expansion of velocity stru cture functions is used to estimate the spreading of the pdfs and to s tudy their scaling properties in the inertial range. Thus, the rate of intermittency depth through the scales of flow, called here beta(R la mbda), is experimentally introduced, and it is shown that beta(R lambd a) has a universal behavior on a very large Reynolds numbers range. (C ) 1998 American Institute of Physics.