TURBULENCE STRUCTURE OF HEAT-TRANSFER THROUGH A 3-DIMENSIONAL TURBULENT BOUNDARY-LAYER

The structure of turbulent heat transfer in the well-documented pressu re-driven, three-dimensional turbulent boundary layer generated by a w ing-body junction was studied experimentally using a constant-current resistance thermometer and a fast-response, thin-layered surface heat flux gauge. Simultaneous time-resolved surface heat nux and temperatur e profile measurements were taken in the spatially developing three-di mensional turbulent boundary layer upstream of the wing. Mean heat tra nsfer was decreased by three dimensionality. Mean temperature profiles showed logarithmic behavior but did not collapse on a law-of-the-wall profile. Statistical and spectral analyses of the temperature fluctua tions provide information on changes to the near-wall turbulent struct ures. The strength of ejections from the near-wall region was decrease d by three dimensionality. Time-delayed correlations of the surface he at flux and now temperature revealed an initially linear turbulent wav e front whose inclination angle increases with three dimensionality. C oherency between wall heat flux and temperature fluctuations in the ou ter boundary layer was decreased by three dimensionality.