Wavenumber analysis of visualized turbulent flowfields

A methodology for performing wave-number analysis on complex visualized flowfields is presented using decaying grid turbulence and turbulent boundary layer flow as example flow cases (a smoke wire is used to make the flows visible). An analysis of two-dimensional wave-number distributions is carried out in order to determine dominant scales. Selected scales are then examined in an effort to determine their physical connections. The approach proposed here provides information that cannot be easily obtained from hot-wire measurements and is complementary to the more conventional experimental methods.