The position- and direction-dependence of length scales in turbulent channel flow was studied using the data from a series of direct numerical simulations (DNSs) of turbulent channel flow with the wall Reynolds number and the number of grid points ranging up to 5120 and 2048 × 1536 × 2048, respectively. According to the DNSs, there is a region of y in which the mean flow profile fits well with the log-law (log-law region), where y is the distance from the wall. The Taylor microscale is anisotropic, but has a simple y-dependence (∝ y1=2) in this region. The two-point fluctuating-velocity correlation at ∣r∣ ∼ y is also anisotropic and approximately depends on r through r=‘ðyÞ, where r is the displacement vector between two points, ‘ðyÞ is a function of only y, and ‘ðyÞ is close to, but not exactly equal to y.
ASJC Scopus subject areas
- Physics and Astronomy(all)