Spatio-temporal turbulent structures of thermal boundary layer subjected to non-equilibrium adverse pressure gradient

We have experimentally investigated a non-equilibrium turbulent boundary layer subjected to an adverse pressure gradient developing on a uniformly heated flat wall. The spatio-temporal structures educed from a multi-point simultaneous measurement are reasonably interpolated based on the proper orthogonal decomposition (POD). In the near-wall region, elongated hot regions stay dull and less active, whereas, large-scale cold regions having strong energy frequently intrude into the near-wall region. The energy-containing events in the near-wall region are discussed based on the results of wavelet analysis. (C) 2008 Elsevier Inc. All rights reserved.