A novel configuration of using a multiple hot-wire probe and an array of skin-friction sensors is developed to study the three dimensional conditional organization of large scale structures in a high Reynolds number turbulent boundary layer. The current study is an extension of the previous work carried out by Hutchins et al. in analyzing the conditional average maps and the amplitude modulation of small scale fluctuations. However, we here report results based on all three components of velocity. The results are significant in two distinct ways, providing deeper insights to the dynamics of the large-scale structures; (1) They show that small-scale v, w and (-uw) are modulated in a very similar manner to that of u, and (2) They demonstrate the existence of roll-modes associated with superstructure events. These have not previously been shown for laboratory data at high Reynolds numbers.
展开▼
