Abstract:

A general processing method is set forth that the di screte orthogonal wavelet theory is used to analyze the 1-D turbulent signal, mainly including decomposition of the pulse velocity and pulse acceleration signals into different scale components. It is got about the profile curves of magnitude and frequency of the scale components having the max turbulent dynamic energy density, and it is also to do so for other scale components having max turbulent dissipation energy density. Under three Reynold numbers the instantaneous velocity and acceleration signals are measured using hot-wire anemometry in a smooth turbulent boundary layer, and then analyzed using the above method. It is concluded that the profile curves ( along y+) of non-dimensional quantity of the two scale lengths have no relation with Reynold number in the boundary layer, that their occurring frequency increases with Reynold numbers, but the frequency of the scale component having the max turbulent dynamic energy density is a constant along y+.

Key words: turbulence, w av elet, or thog onal analy sis, tur bulent dy namic energ y, turbulent dissipatio n